0001558370-20-006274 | 10-Q | XBRL Viewer

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2020	May 07, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-36279
Entity Registrant Name	CARA THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	75-3175693
Entity Address, Address Line One	4 Stamford Plaza
Entity Address, Address Line Two	107 Elm Street
Entity Address, Address Line Three	9th Floor
Entity Address, City or Town	Stamford
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06902
City Area Code	203
Local Phone Number	406-3700
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	CARA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		46,796,059
Entity Central Index Key	0001346830
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 17,036	$ 18,305
Marketable securities	103,160	136,701
Income tax receivable	938	816
Other receivables	847	971
Prepaid expenses	10,688	8,863
Total current assets	132,669	165,656
Operating lease right-of-use asset	2,876	3,036
Marketable securities, non-current	59,568	63,159
Property and equipment, net	652	700
Restricted cash	408	408
Total assets	196,173	232,959
Current liabilities:
Accounts payable and accrued expenses	17,371	19,665
Operating lease liability, current	991	967
Current portion of deferred revenue	14,241	22,262
Total current liabilities	32,603	42,894
Operating lease liability, non-current	3,096	3,352
Commitments and contingencies (Note 15)
Stockholders' equity:
Preferred stock; $0.001 par value; 5,000,000 shares authorized at March 31, 2020 and December 31, 2019, zero shares issued and outstanding at March 31, 2020 and December 31, 2019
Common stock; $0.001 par value; 100,000,000 shares authorized at March 31, 2020 and December 31, 2019, 46,727,725 shares and 46,720,225 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	47	47
Additional paid-in capital	590,144	587,223
Accumulated deficit	(429,649)	(400,727)
Accumulated other comprehensive income (loss)	(68)	170
Total stockholders' equity	160,474	186,713
Total liabilities and stockholders' equity	$ 196,173	$ 232,959

Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Total revenue	$ 8,093	$ 4,382
Operating expenses:
Research and development	33,536	23,608
General and administrative	4,558	3,908
Total operating expenses	38,094	27,516
Operating loss	(30,001)	(23,134)
Other income, net	957	1,089
Loss before benefit from income taxes	(29,044)	(22,045)
Benefit from income taxes	122	85
Net loss	$ (28,922)	$ (21,960)
Net loss per share:
Basic and Diluted	$ (0.62)	$ (0.56)
Weighted average shares:
Basic and Diluted	46,724,951	39,552,277
Other comprehensive income (loss), net of tax of $0:
Change in unrealized gains (losses) on available-for-sale marketable securities	$ (238)	$ 187
Total comprehensive loss	(29,160)	(21,773)
License and Milestone Fees [Member]
Revenue:
Total revenue	8,021	4,242
Clinical Compound Revenue [Member]
Revenue:
Total revenue	$ 72	$ 140

Condensed Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance, Value at Dec. 31, 2018	$ 39	$ 428,059	$ (294,354)	$ (114)	$ 133,630
Balance, Shares at Dec. 31, 2018	39,547,558
Stock-based compensation expense		2,234			2,234
Shares issued upon exercise of stock options, Value		234			234
Shares issued upon exercise of stock options, Shares	17,291
Shares issued for consulting services		197			197
Shares issued for consulting services, Shares	10,195
Net loss			(21,960)		(21,960)
Other comprehensive income (loss)				187	187
Balance, Value at Mar. 31, 2019	$ 39	430,724	(316,314)	73	114,522
Balance, Shares at Mar. 31, 2019	39,575,044
Balance, Value at Dec. 31, 2019	$ 47	587,223	(400,727)	170	186,713
Balance, Shares at Dec. 31, 2019	46,720,225
Stock-based compensation expense		2,846			2,846
Shares issued upon exercise of stock options, Value		75			75
Shares issued upon exercise of stock options, Shares	7,500
Net loss			(28,922)		(28,922)
Other comprehensive income (loss)				(238)	(238)
Balance, Value at Mar. 31, 2020	$ 47	$ 590,144	$ (429,649)	$ (68)	$ 160,474
Balance, Shares at Mar. 31, 2020	46,727,725

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
Condensed Statements of Cash Flows - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Operating activities
Net loss	$ (28,922)	$ (21,960)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,846	2,234
Depreciation and amortization	48	50
Amortization expense component of lease expense	160	145
Accretion of available-for-sale marketable securities, net	(65)	(478)
Deferred revenue	(8,021)	(4,242)
Changes in operating assets and liabilities:
Income tax receivable	(122)	(85)
Other receivables	124	(93)
Prepaid expenses	(1,825)	(2,574)
Accounts payable and accrued expenses	(2,294)	(312)
Operating lease liability	(232)	(211)
Net cash used in operating activities	(38,303)	(27,526)
Investing activities
Proceeds from maturities of available-for-sale marketable securities	55,475	79,295
Proceeds from the redemptions of available-for-sale marketable securities, at par	2,500
Purchases of available-for-sale marketable securities	(21,016)	(52,885)
Purchases of property and equipment		(11)
Net cash provided by investing activities	36,959	26,399
Financing activities
Proceeds from the exercise of stock options	75	234
Net cash provided by financing activities	75	234
Net decrease in cash, cash equivalents and restricted cash	(1,269)	(893)
Cash, cash equivalents and restricted cash at beginning of period	18,713	15,850
Cash, cash equivalents and restricted cash at end of period	$ 17,444	14,957
Noncash investing and financing activities
Shares of common stock issued in exchange for consulting services		$ 197

Basis of Presentation

3 Months Ended

Mar. 31, 2020

Basis of Presentation

Basis of Presentation

2. Basis of Presentation

The unaudited interim condensed financial statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission, or SEC. Accordingly, they do not include all information and disclosures necessary for a presentation of the Company’s financial position, results of operations and cash flows in conformity with generally accepted accounting principles in the United States of America, or GAAP. In the opinion of management, these unaudited interim financial statements reflect all adjustments, consisting primarily of normal recurring accruals, necessary for a fair presentation of results for the periods presented. The results of operations for interim periods are not necessarily indicative of the results for the full year. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by SEC rules and regulations; however, the Company believes that the disclosures are adequate to make the information presented not misleading. The condensed balance sheet data as of December 31, 2019 were derived from audited financial statements, but do not include all disclosures required by GAAP. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and accompanying notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, as of the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Significant estimates include the fair value of marketable securities that are classified as level 2 of the fair value hierarchy, useful lives of fixed assets, the periods over which certain revenues will be recognized, including licensing and collaborative revenue recognized from non-refundable up-front and milestone payments, the determination of prepaid research and development, or R&D, clinical costs and accrued research projects, the amount of non-cash compensation costs related to share-based payments to employees and non-employees and the periods over which those costs are expensed, the incremental borrowing rate used in lease calculations and the likelihood of realization of deferred tax assets.

The COVID-19 pandemic is expected to result in a slowdown of economic activity that is likely to interrupt business operations across the globe. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these condensed financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the reported amounts of assets and liabilities or the disclosure of contingent assets and liabilities. These estimates, however, may change as new events occur and additional information is obtained, and are recognized in the condensed financial statements as soon as they become known.

Actual results could differ materially from the Company’s estimates and assumptions.

Significant Accounting Policies

There have been no material changes to the significant accounting policies previously disclosed in Note 2 to the Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, except for the recent adoption of new accounting pronouncements as disclosed below.

Accounting Pronouncements Recently Adopted

On January 1, 2020, the Company adopted Accounting Standards Update, or ASU, No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, or ASU 2016-13, which replaces the incurred loss impairment methodology in prior GAAP that delays recognition of a credit loss until it is probable that such loss has been incurred, with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates.

The Company deems certain of its investments to be marketable securities if the investment, or in the case of money market funds, the securities underlying the money market fund, meet the definition of a debt security in Accounting Standards Codification, or ASC, section 320-10-20. The Company considers its marketable securities to be available-for-sale, which are its only financial instruments that are within the scope of ASU 2016-13 as of March 31, 2020. The Company’s investments in marketable securities, including U.S. Treasury securities, U.S. government agency obligations, corporate bonds, commercial paper and municipal bonds, are highly rated by Moody’s and S&P and have maturities primarily of less than one year but no longer than two years. Accordingly, credit risk associated with the Company’s available-for-sale debt security portfolio is mitigated.

ASU 2016-13 modifies the prior other-than-temporary impairment model for available-for-sale debt securities by requiring (1) estimating expected credit losses (the portion of the amortized cost basis of a financial asset that the

Company does not expect to collect) only when the fair value is below the amortized cost of the asset; (2) recording a credit loss without regard to the length of time a security has been in an unrealized loss position; (3) limiting the measurement of the credit loss to the difference between the security’s amortized cost basis and its fair value; and (4) presenting credit losses as an allowance rather than as a write-down, which will allow the Company to record reversals of credit losses in current period net income, a practice that was previously prohibited. In April and November 2019, respectively, codification improvements were issued to help clarify and correct certain portions of ASU 2016-13.

The Company reviews each of its available-for-sale marketable securities for unrealized losses (declines in fair value below its amortized cost basis) at each balance sheet date presented in its financial statements and whenever events or changes in circumstances indicate that the amortized cost basis of an asset may not be recoverable. In accordance with the adoption of ASU 2016-13, the Company is required to determine whether any portion of the unrealized loss for any available-for-sale debt security is due to a credit loss, and if so, to measure the amount of the credit loss.

The Company will rely on both qualitative and quantitative factors to determine whether the unrealized loss for each available-for-sale debt security at any balance sheet date is due to a credit loss.

Qualitative factors may include a credit downgrade, severity of the decline in fair value below amortized cost and other adverse conditions related specifically to the security, as well as the intent to sell the security, or whether the Company will more likely than not be required to sell the security before recovery of its amortized cost basis. The Company’s assessment of whether a security is impaired could change in the future due to new developments or changes in assumptions related to any particular security. If material qualitative factors indicate that a credit loss has occurred, the Company will determine the magnitude of that credit loss using a discounted cash flow model or other quantitative method.

If the Company intends to sell the security or it is more likely than not that the Company will be forced to sell the security before recovery of the amortized cost of the security, the entire unrealized loss is deemed to be a credit loss, which is recognized in net income (loss). Otherwise, the portion of the unrealized loss that is due to a credit loss will be recorded as an Allowance for Credit Loss, which will offset the balance of Marketable Securities on the Condensed Balance Sheets and as credit loss expense within other income, net on the Condensed Statements of Comprehensive Loss. The portion of the unrealized loss that is not due to a credit loss as well as all unrealized gains will be recorded in Accumulated Other Comprehensive Income (Loss), or AOCI, net of taxes, on the Condensed Balance Sheets. There was no cumulative effect adjustment as a result of the adoption of ASU 2016-13 on January 1, 2020 (see Note 3, Available-for-Sale Marketable Securities, and Note 5, Fair Value Measurements).

Accrued interest receivables are excluded from the Company’s amortized cost bases for its available-for-sale marketable securities and are included within Other Receivables on the Company’s Condensed Balance Sheets. The Company’s policy is to not measure an allowance for credit losses on accrued interest receivable balances at each reporting period since it elects to write off uncollectible accrued interest receivable balances as credit loss expense in a timely manner, which is by maturity date for all categories of its debt securities.

On January 1, 2020, the Company adopted ASU 2019-08, Compensation – Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606), or ASU 2019-08, which requires the Company to measure and classify share-based payment awards granted to a customer by applying the guidance in Topic 718. The amount recorded as a reduction to the transaction price is required to be measured on the basis of the grant-date fair value of the share-based payment award in accordance with Topic 718. The grant date is the date at which a grantor (supplier) and a grantee (customer) reach a mutual understanding of the key terms and conditions of a share-based payment award. The classification and subsequent measurement of the award are subject to the guidance in Topic 718 unless the share-based payment award is subsequently modified and the grantee is no longer a customer. The adoption of ASU 2019-08 did not

have a material effect on its results of operations, financial position or cash flows since the Company has not historically granted share-based payment awards to customers.

On January 1, 2020, the Company adopted ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, or ASU 2018-18, which clarifies the interaction between Topic 808 and Topic 606 by (1) clarifying that certain transactions between collaborative arrangement participants should be accounted for under Topic 606; (2) adding unit-of-account guidance in Topic 808 to align with the guidance in Topic 606; and (3) clarifying presentation guidance for transactions with a collaborative arrangement participant that are not accounted for under Topic 606. The adoption of ASU 2018-18 did not have any effect on its financial position, results of operations or cash flows since all three of its collaboration and licensing agreements are accounted for under Topic 606 (see Note 10, Collaboration and Licensing Agreements and Note 11, Revenue Recognition).

On January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, or ASU 2018-13, which modifies the disclosure requirements on fair value measurements in Topic 820 to remove the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements. ASU 2018-13 also amends Topic 820 to clarify that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. ASU 2018-13 also requires additional disclosure for changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period as well as the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. Upon adoption of ASU 2018-13, the Company did not have any assets or liabilities that are included in Level 3 fair value measurements and no retrospective treatment was applicable. As a result, the adoption of ASU 2018-13 did not have a material effect on its results of operations, financial position or cash flows.

Accounting Pronouncements Not Yet Adopted

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740), or ASU 2019-12, which removes specific exceptions to the general principles in Topic 740. ASU 2019-12 eliminates the need for an organization to analyze whether the following apply in a given period: i) exception to the incremental approach for intra-period tax allocation; ii) exceptions to accounting for basis differences when there are ownership changes in foreign investments; and iii) exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss. ASU 2019-12 also simplifies the accounting for income taxes for: i) franchise taxes that are partially based on income; ii) transactions with a government that result in a step up in the tax basis of goodwill; (iii) separate financial statements of legal entities that are not subject to tax; and iv) enacted changes in tax laws in interim periods. The amendments in ASU 2019-12 are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of the amendments is permitted. An entity that elects to early adopt the amendments in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period and must adopt all the amendments in the same period. The amendments in ASU 2019-12 related to separate financial statements of legal entities that are not subject to tax should be applied on a retrospective basis for all periods presented. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The amendments related to franchise taxes that are partially based on income should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. All other amendments should be applied on a prospective basis. As such, the Company expects to adopt ASU 2019-12 on January 1, 2021 and is currently evaluating the effect it will have on its results of operations, financial position and cash flows.

Available-for-Sale Marketable Securities

3 Months Ended

Mar. 31, 2020

Investments Debt And Equity Securities [Abstract]

Available-for-Sale Marketable Securities

3. Available-for-Sale Marketable Securities

As of March 31, 2020 and December 31, 2019, the Company’s available-for-sale marketable securities consisted of debt securities issued by the U.S. Treasury, U.S. government-sponsored entities and investment grade institutions as well as municipal bonds.

The following tables summarize the Company’s available-for-sale marketable securities by major type of security as of March 31, 2020 and December 31, 2019:

As of March 31, 2020


			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	16,065	$	249	$	—	$	16,314
U.S. government agency obligations		17,601		39		(1)		17,639
Corporate bonds		93,681		79		(460)		93,300
Commercial paper		31,949		26		—		31,975
Municipal bonds		3,500		—		—		3,500
Total available-for-sale marketable securities	$	162,796	$	393	$	(461)	$	162,728

As of December 31, 2019


			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	16,052	$	31	$	(2)	$	16,081
U.S. government agency obligations		25,803		14		(1)		25,816
Corporate bonds		115,788		125		(23)		115,890
Commercial paper		38,547		27		(1)		38,573
Municipal bonds		3,500		—		—		3,500
Total available-for-sale marketable securities	$	199,690	$	197	$	(27)	$	199,860

The following tables summarize the fair value and gross unrealized losses of the Company’s available-for-sale marketable securities by investment category and disaggregated by the length of time that individual debt securities have been in a continuous unrealized loss position.

As of March 31, 2020


	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. government agency obligations	$	4,248	$	(1)	$	—	$	—	$	4,248	$	(1)
Corporate bonds		63,046		(460)		—		—		63,046		(460)
Total	$	67,294	$	(461)	$	—	$	—	$	67,294	$	(461)

As of December 31, 2019


	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	3,185	$	(2)	$	—	$	—	$	3,185	$	(2)
U.S. government agency obligations		2,400		(1)		—		—		2,400		(1)
Corporate bonds		28,895		(23)		—		—		28,895		(23)
Commercial paper		4,264		(1)		—		—		4,264		(1)
Total	$	38,744	$	(27)	$	—	$	—	$	38,744	$	(27)

As of March 31, 2020 and December 31, 2019, respectively, no allowance for credit losses were recognized on the Company’s available-for-sale debt securities as no portion of the unrealized losses associated with those securities were due to credit losses. The information that the Company considered in reaching the conclusion that an allowance for credit losses was not necessary for the following categories of securities is as follows:

As of March 31, 2020 and December 31, 2019, the Company held a total of 29 out of 68 positions and 16 out of 81 positions, respectively, that were in an unrealized loss position, none of which had been in an unrealized loss position for 12 months or greater. Unrealized losses individually and in aggregate were not considered to be material for each respective period. Based on the Company’s review of these securities, the Company believes that the cost basis of its available-for-sale marketable securities is recoverable.

U.S. government agency obligations. The unrealized losses on the Company’s investments in direct obligations of U.S. government agencies were caused by reduced liquidity in this category of debt securities due to the COVID-19 pandemic. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost bases of the investments. The Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases. As of March 31, 2020, the Company held 1 out of 6 positions in an unrealized loss position for its U.S. government agency obligations.

Corporate bonds. The unrealized losses on the Company’s investments in corporate bonds relate to increased volatility and reduced liquidity in the investment grade corporate debt market due to the COVID-19 pandemic. The credit ratings of the corporate bonds in the Company’s portfolio have not been downgraded below investment grade status as a result of the pandemic. The Company expects to recover the entire amortized cost bases of those securities as the pandemic subsides and markets normalize. The Company does not intend to sell its investments in corporate bonds, and it is not more likely than not that the Company will be required to sell those investments before recovery of their amortized cost bases. As of March 31, 2020, the Company held 28 out of 42 positions in an unrealized loss position for its corporate bonds.

The Company classifies its marketable debt securities based on their contractual maturity dates. As of March 31, 2020, the Company’s marketable debt securities mature at various dates through December 2021. The amortized cost and fair values of marketable debt securities by contractual maturity were as follows.


	As of March 31, 2020				As of December 31, 2019
Contractual maturity	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than one year	$	103,142	$	103,160	$	136,565	$	136,701
One year to two years		59,654		59,568		63,125		63,159
Total	$	162,796	$	162,728	$	199,690	$	199,860

All available-for-sale marketable securities are classified as Marketable securities, current or Marketable securities, non-current depending on the contractual maturity date of the individual available-for-sale security. Other income includes interest and dividends, accretion/amortization of discounts/premiums, realized gains and losses on sales of securities and credit loss expense due to declines in the fair value of securities, if any. The cost of securities sold is based on the specific identification method.

There were no sales of available-for-sale marketable securities during the three months ended March 31, 2020 and 2019, respectively.

As of March 31, 2020 and December 31, 2019, accrued interest receivables on our available-for-sale debt securities were $847 and $971, respectively.

Fair Value Measurements

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurements

5. Fair Value Measurements

As of March 31, 2020 and December 31, 2019, the Company’s financial instruments consisted of cash, cash equivalents, available-for-sale marketable securities, prepaid expenses, restricted cash, accounts payable and accrued liabilities. The fair values of cash, cash equivalents, prepaid expenses, restricted cash, accounts payable and accrued liabilities approximate their carrying values due to the short-term nature of these financial instruments. Available-for-sale marketable securities are reported on the Company’s Condensed Balance Sheets as Marketable Securities at their fair values, based upon pricing of securities with the same or similar investment characteristics as provided by third-party pricing services, as described below.

Current accounting guidance defines fair value, establishes a framework for measuring fair value in accordance with ASC section 820, and requires certain disclosures about fair value measurements. The valuation techniques included in

the guidance are based on observable and unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, while unobservable inputs reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances.

The Company classifies its investments in a fair value hierarchy that is intended to increase consistency and comparability in fair value measurements and related disclosures. The fair value hierarchy is divided into three levels based on the source of inputs as follows:

●

Level 1 – Observable inputs – quoted prices in active markets for identical assets and liabilities.

●

Level 2 – Observable inputs other than the quoted prices in active markets for identical assets and liabilities – such as quoted prices for similar instruments, quoted prices for identical or similar instruments in inactive markets, or other inputs that are observable or can be corroborated by observable market data.

●

Level 3 – Unobservable inputs – includes amounts derived from valuation models where one or more significant inputs are unobservable and require the Company to develop relevant assumptions.

Valuation Techniques - Level 2 Inputs

The Company estimates the fair values of its financial instruments categorized as level 2 in the fair value hierarchy, including U.S. Treasury securities, U.S. government agency obligations, corporate bonds, commercial paper and municipal bonds, by taking into consideration valuations obtained from third-party pricing services. The pricing services use industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, benchmark yields, issuer credit spreads, benchmark securities, and other observable inputs. The Company obtains a single price for each financial instrument and does not adjust the prices obtained from the pricing service.

The Company validates the prices provided by its third-party pricing services by reviewing their pricing methods, obtaining market values from other pricing sources and comparing them to the share prices presented by the third-party pricing services. After completing its validation procedures, the Company did not adjust or override any fair value measurements provided by its third-party pricing services as of March 31, 2020 or December 31, 2019.

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019.

Fair value measurement as of March 31, 2020:


			Quoted prices in		Significant other		Significant
Financial assets			active markets for		observable		unobservable
			identical assets		inputs		inputs
Type of Instrument	Total		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents:
Money market funds and checking accounts	$	17,036	$	17,036	$	—	$	—
Available-for-sale marketable securities:
U.S. Treasury securities		16,314		—		16,314		—
U.S. government agency obligations		17,639		—		17,639		—
Corporate bonds		93,300		—		93,300		—
Commercial paper		31,975		—		31,975		—
Municipal bonds		3,500		—		3,500		—
Restricted cash:
Commercial money market account		408		408		—		—
Total financial assets	$	180,172	$	17,444	$	162,728	$	—

Fair value measurement as of December 31, 2019:


			Quoted prices in		Significant other		Significant
Financial assets			active markets for		observable		unobservable
			identical assets		inputs		inputs
Type of Instrument	Total		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents:
Money market funds and checking accounts	$	18,305	$	18,305	$	—	$	—
Available-for-sale marketable securities:
U.S. Treasury securities		16,081		—		16,081		—
U.S. government agency obligations		25,816		—		25,816		—
Corporate bonds		115,890		—		115,890		—
Commercial paper		38,573		—		38,573		—
Municipal bonds		3,500		—		3,500		—
Restricted cash:
Commercial money market account		408		408		—		—
Total financial assets	$	218,573	$	18,713	$	199,860	$	—

There were no purchases, sales or maturities of Level 3 financial assets and no unrealized gains or losses related to Level 3 available-for-sale marketable securities during the three months ended March 31, 2020 and 2019, respectively. There were no transfers of financial assets into or out of Level 3 classification during the three months ended March 31, 2020 and 2019, respectively.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Collaboration and Licensing Agreements

3 Months Ended

Mar. 31, 2020

Basis of Presentation

Collaboration and Licensing Agreements

10. Collaboration and Licensing Agreements

Vifor Fresenius Medical Care Renal Pharma Ltd.

On May 17, 2018, the Company entered into a license agreement, or the VFMCRP Agreement, with VFMCRP under which the Company granted VFMCRP an exclusive, royalty-bearing license, or the VFMCRP License, to seek regulatory approval to commercialize, import, export, use, distribute, offer for sale, promote, sell and otherwise commercialize CR845/difelikefalin injection, or the Licensed Product, for all therapeutic uses to prevent, inhibit or treat itch associated with pruritus in hemodialysis and peritoneal-dialysis patients, or the Field, worldwide (excluding the United States, Japan and South Korea), or the Territory.

Upon entry into the VFMCRP Agreement, VFMCRP made a non-refundable, non-creditable $50,000 upfront payment to the Company and Vifor purchased 1,174,827 shares of the Company’s common stock, or the Vifor Shares, for $20,000 at a price of $17.024 per share, which represents a premium over a pre-determined average closing price of the Company’s common stock. The purchase of the Company’s common stock was governed by a separate stock purchase agreement. The excess of the stock purchase price over the cost of the Vifor Shares at the closing price of the Company’s common stock on the purchase date of $5,444 was added to the upfront payment for accounting purposes.

The Company is eligible to receive from VFMCRP regulatory and commercial milestone payments in the aggregate of up to $470,000, consisting of up to $30,000 in regulatory milestones and up to $440,000 in tiered commercial milestones, all of which are sales-related. The Company is also eligible to receive tiered double-digit royalty payments based on annual net sales, as defined in the VFMCRP Agreement, of CR845/difelikefalin injection in the Licensed Territories. The Company retains full commercialization rights for CR845/difelikefalin injection for the treatment of CKD-aP in the United States except in the dialysis clinics of Fresenius Medical Care North America, or FMCNA, where VFMCRP and the Company will promote CR845/difelikefalin injection under a profit-sharing arrangement (subject to the terms and conditions of the VFMCRP Agreement) based on net FMCNA clinic sales recorded by the Company.

At inception of the VFMCRP Agreement, the transaction price of $55,444 was allocated entirely to the one combined performance obligation, as described above, and was initially recorded as deferred revenue. License and milestone revenue will be recognized proportionately as the R&D services are conducted (i.e., prior to submission of a New Drug Application, or NDA).

The license also requires VFMCRP to promote and take orders in the U.S. for sale by the Company to FMC U.S. Dialysis Clinics and allows VFMCRP to grant sub-licenses, which, in certain cases, requires the Company’s prior written consent. The Company retains the rights to import, distribute, promote, sell and otherwise commercialize the Licensed Product outside of the Field and outside of the Territory.

The Company retains the rights to make and have made the Licensed Product in the Territory for commercial sale by VFMCRP in the Field in or outside the Territory and for supply of Licensed Product to VFMCRP under the terms of a supply agreement, or the Supply Agreement. The supply price will be the Company’s cost of goods sold, as calculated under U.S. GAAP, plus an agreed upon margin. The Supply Agreement will co-terminate with the VFMCRP Agreement. In regards to a supply agreement, the VFMCRP Agreement only includes a requirement for the Company to negotiate in good faith with VFMCRP. After the execution of the VFMCRP Agreement, a separate agreement to supply them with the Licensed Product would be entered into, although the Company has no obligation to execute a supply agreement. In the event that the parties fail to enter into a Supply Agreement or if the Company fails to provide Licensed Product on a timely basis, VFMCRP has the right to manufacture or have manufactured the Licensed Product in and outside the Territory.

The Supply Agreement will be accounted for as a customer option that is not a material right because the selling price of the Licensed Product under the Supply Agreement is the Company’s cost of goods sold plus an agreed upon margin, which is commensurate with the “cost of goods sold plus” model that the Company would charge other parties under similar agreements (the standalone selling price) and not at a discount. Therefore, the sale of clinical compound to VFMCRP is not a performance obligation under the VFMCRP Agreement but rather the Supply Agreement is a separate agreement from the VFMCRP Agreement. The only performance obligation under the Supply Agreement is the delivery of the Licensed Product to VFMCRP for commercialization. Revenue from the sale of the Licensed Product to VFMCRP will be recognized as Clinical Supply revenue in the Company’s Statements of Comprehensive Loss as sales of the Licensed Product occur. As of March 31, 2020, no supply agreement has been entered into between the Company and VFMCRP.

The VFMCRP Agreement terminates upon the expiration of all royalty terms with respect to the Licensed Products, which expire on a Product-by-Product and country-by-country basis, at the latest of (a) the expiration of all patent rights licensed to VFMCRP covering such Licensed Product; (b) the expiration of all regulatory and data exclusivity applicable to such Licensed Product in such country and (c) the tenth anniversary of the first commercial sale of such Product in such country.

The VFMCRP Agreement may be terminated earlier by either party for material breach that is not cured within 60 days, bankruptcy by either party and by both parties upon mutual written consent. The Company may terminate the VFMCRP Agreement if VFMCRP challenges the validity of any licensed patent rights, except if such patent challenge results from the Company’s action against VFMCRP for infringement of any licensed patent in the Territory. In addition, upon the earlier of (1) the acceptance for filing of an NDA covering Licensed Product filed with the FDA (after completion of the Phase 3 program) or (2) the third anniversary of the Effective Date, the VFMCRP Agreement may be terminated by VFMCRP in its entirety or with respect to any countries within the Territory upon written notice to the Company. Such termination will be effective twelve months following the date of such notice.

If the VFMCRP Agreement terminates early for any reason stated above, VFMCRP’s licenses will terminate, VFMCRP’s rights to use the Company’s confidential information and the Company’s know-how will revert to the Company and VFMCRP will assign and transfer to the Company all right, title and interest in all regulatory applications (IND’s and NDA’s), regulatory approval applications and regulatory approvals in the Territory covering Licensed Product.

Maruishi Pharmaceutical Co., Ltd.

In April 2013, the Company entered into a license agreement with Maruishi, or the Maruishi Agreement, under which the Company granted Maruishi an exclusive license to develop, manufacture, and commercialize drug products containing CR845/difelikefalin for acute pain and/or uremic pruritus in Japan. Maruishi has the right to grant sub-licenses in Japan, which entitles the Company to receive sub-license fees, net of prior payments made by Maruishi to the Company. Under the Maruishi Agreement, the Company and Maruishi are required to use commercially reasonable efforts, at their own expense, to develop, obtain regulatory approval for and commercialize CR845/difelikefalin in the United States and Japan, respectively. In addition, the Company provided Maruishi specific clinical development services for CR845/difelikefalin used in Maruishi’s field of use.

Under the terms of the Maruishi Agreement, the Company is eligible to receive milestone payments upon the achievement of defined clinical and regulatory events as well as tiered, low double-digit royalties with respect to any sales of the licensed product sold in Japan by Maruishi, if any, and share in any sub-license fees.

During the three months ended March 31, 2020 and 2019, the Company recognized clinical compound revenue of $72 and $140, respectively, from the sale of clinical compound to Maruishi and as a result, the Company incurred R&D expense of $65 and $126, respectively, during these respective periods.

Chong Kun Dang Pharmaceutical Corporation

In April 2012, the Company entered into a license agreement, or the CKDP Agreement, with Chong Kun Dang Pharmaceutical Corporation, or CKDP, in South Korea, under which the Company granted CKDP an exclusive license to develop, manufacture and commercialize drug products containing CR845/difelikefalin in South Korea. The Company and CKDP are each required to use commercially reasonable efforts, at their respective expense, to develop, obtain regulatory approval for and commercialize CR845/difelikefalin in the United States and South Korea, respectively. The Company identified the granting of the license as its only performance obligation under the CKDP Agreement.

Under the terms of the CKDP Agreement, the Company is eligible to receive milestone payments upon the achievement of defined clinical and regulatory events as well as tiered royalties, with percentages ranging from the high single digits to the high teens, based on net sales of products containing CR845/difelikefalin in South Korea, if any, and share in any sub-license fees.

Revenue Recognition

3 Months Ended

Mar. 31, 2020

Revenue Recognition [Abstract]

Revenue Recognition

11. Revenue Recognition

The Company currently recognizes revenue in accordance with ASC 606, as amended, for the VFMCRP, Maruishi and CKDP agreements (see Note 10, Collaboration and Licensing Agreements). Under each of these agreements, the Company has recognized revenue from upfront payments and, under the Maruishi Agreement and the CKDP Agreement, from clinical development milestone payments. The Company has also recognized revenue from a sub-license payment earned under the Maruishi Agreement. Under the Maruishi Agreement and the CKDP Agreement, the Company may earn additional future milestone payments upon the achievement of defined clinical events, and under the VFMCRP Agreement, the Maruishi Agreement and the CKDP Agreement, upon the achievement of defined regulatory events, and under the VFMCRP Agreement and the Maruishi Agreement, from sales milestones. The Company may also recognize revenue in the future from royalties on net sales under all three agreements. In addition, the Company has recognized revenue upon the delivery of clinical compound to Maruishi in accordance with separate supply agreements.

Contract balances

As of March 31, 2020, the Company had deferred revenue, current of $14,241 related to the performance obligations from the VFMCRP Agreement and had no balances of receivables, other assets or deferred revenue, non-current related to the VFMCRP Agreement. There were no balances of receivables, other assets or deferred revenue relating to the Maruishi and CKDP agreements as of March 31, 2020. As of December 31, 2019, the Company had deferred revenue, current of $22,262 related to the performance obligations from the VFMCRP Agreement and had no balances of receivables, other assets or deferred revenue, non-current related to the VFMCRP Agreement. There were no balances of receivables, other assets or deferred revenue relating to the Maruishi and CKDP agreements as of December 31, 2019.

Performance obligations

Under the VFMCRP Agreement, the Company’s performance obligations of granting a license to allow VFMCRP to commercialize CR845/difelikefalin injection worldwide, except in the United States, Japan and South Korea, which occurred at inception of the contract in May 2018, and performing R&D services by the Company to obtain sufficient clinical data which will be shared with VFMCRP to allow them to receive regulatory approval to sell

CR845/difelikefalin in the licensed territory, are not distinct, and are accounted for as a single performance obligation during the period that the R&D services are rendered (see Note 10, Collaboration and Licensing Agreements).

The Company’s distinct performance obligations under the Maruishi Agreement include transfer of the license to the Company’s IP, which allowed Maruishi to develop and commercialize CR845/difelikefalin, for acute pain and uremic pruritus indications in Japan, which occurred at inception of the contract in 2013, and performance of R&D services, which occurred from 2013 to 2015, as those services were rendered. The Company agreed to conduct limited work on an oral tablet formulation of CR845/difelikefalin and to conduct Phase 1 and proof-of-concept Phase 2 clinical trials of an intravenous formulation of CR845/difelikefalin to be used to treat patients with uremic pruritus. The Company agreed to transfer the data and information from such development to Maruishi for its efforts to obtain regulatory approval in Japan. These activities are referred to as R&D services.

The Company’s only performance obligation under the supply agreement with Maruishi is to deliver clinical compound to Maruishi in accordance with the receipt of purchase orders. If and when the Company enters into a supply agreement with VFMCRP, the Company’s only performance obligation under this supply agreement would be to deliver CR845/difelikefalin injection to VFMCRP in accordance with the receipt of purchase orders.

Under the CKDP Agreement, the Company’s only performance obligation is to transfer the license to the Company’s IP related to CR845/difelikefalin, which occurred at inception of the contract in 2012.

Upon execution of the VFMCRP Agreement, the Maruishi Agreement and the CKDP Agreement, the Company received a single fixed payment from each counterparty in exchange for granting the respective licenses and performing its other obligations. In addition, each of the counterparties made an equity investment in the Company’s common stock.

Transaction price allocated to the remaining performance obligations

At inception of the VFMCRP Agreement, the entire transaction price of $55,444 was allocated to the one combined performance obligation, as described above. For the three months ended March 31, 2020, $8,021 was recognized as license and milestone fees revenue based on the percentage of R&D services that were completed during the period. As of March 31, 2020, $41,203 of the $55,444 has been recognized as license and milestone fees revenue based on the percentage of R&D services that has been completed since the inception of the VFMCRP Agreement. As of March 31, 2020, there were no remaining performance obligations under either the Maruishi Agreement or the CKDP Agreement, although the Company is eligible to receive milestone payments and sales royalties in the future.

Significant judgments

In applying ASC 606, as amended, to its three contracts, the Company made the following judgments that significantly affect the timing and amount of revenue recognition:

Determination of the number of distinct performance obligations in a contract

The VFMCRP Agreement contains one combined performance obligation, which includes the Company’s two performance obligations to grant a license to VFMCRP and conduct R&D services. Both of those performance obligations are inputs to the promise, within the context of the contract, to transfer a combined output for which VFMCRP has contracted (the ability of VFMCRP to commercialize the Licensed Product) (see Note 10, Collaboration and Licensing Agreements, for further discussion).

The Maruishi Agreement contains two distinct performance obligations: the granting of the license and the promise to deliver defined R&D services. Under the Maruishi Agreement, the license and the R&D services represent distinct goods or services from each other because Maruishi is able to benefit from the license on its own or together with other resources that are readily available to it (i.e., capable of being distinct). Maruishi’s ability to benefit from the license without the R&D services is indicated by its ability to conduct clinical trials of CR845/difelikefalin on its own and by the provision in the Maruishi Agreement whereby if the Company suspends or discontinues its development activity, the Company will provide information regarding its development efforts up to that point so that Maruishi may continue development and commercialization of the product in Japan. Therefore, the R&D services do not significantly affect Maruishi’s ability to use and benefit from the license.

In addition, the Company’s promise in the Maruishi contract to transfer the license is separately identifiable from the promise to provide defined R&D services (i.e., distinct within the context of the contract) because the Company is not using the goods or services as inputs to produce or deliver the combined output or outputs specified by the customer. The combined output specified by Maruishi is its right to conduct development activities related to CR845/difelikefalin in Japan, which could result in regulatory approval in Japan. That right is derived from the Company’s grant of the license. Maruishi is conducting clinical trials on its own and does not require the R&D services provided by the Company. Furthermore, the R&D services do not significantly modify or customize the license and vice versa. Finally, the license and R&D services are not highly interdependent or highly interrelated because the Company is able to fulfill its promise to transfer the initial license independently from its promise to subsequently provide the R&D services, which Maruishi can obtain on its own.

The only performance obligation in the CKDP Agreement is the granting of the license.

Determination of the transaction price, including whether any variable consideration is included at inception of the contract

The transaction price is the amount of consideration that the Company expects to be entitled to in exchange for transferring promised goods or services to the customer. The transaction price must be determined at inception of a contract and may include amounts of variable consideration. However, there is a constraint on inclusion of variable consideration, such as milestone payments or sales-based royalty payments, in the transaction price related to licenses of IP, if there is uncertainty at inception of the contract as to whether such consideration will be recognized in the future.

The decision as to whether or not it is probable that a significant reversal of revenue will occur in the future, depends on the likelihood and magnitude of the reversal and is highly susceptible to factors outside the entity’s influence (for example, the Company cannot determine the outcome of clinical trials; the Company cannot determine if or when they or the counterparty will initiate or complete clinical trials; and the Company’s ability to obtain regulatory approval is difficult). In addition, the uncertainty is not expected to be resolved for a long period of time (in the order of years) and finally, the Company has limited experience in the field.

Therefore, at inception of the VFMCRP Agreement, the Maruishi Agreement and the CKDP Agreement, milestones and sales-based royalty payments were not included in the transaction price based on the factors noted above.

Under the VFMCRP Agreement, the single combined performance obligation will be satisfied as the R&D services are rendered and the transaction price, including the upfront payment of $50,000 and the premium on the common stock purchased by VFMCRP of $5,444, will be recognized as revenue as the R&D services are performed based on the costs incurred as a percentage of the estimated total costs to be incurred to complete the performance obligation. The remaining potential consideration was considered to be variable consideration and was constrained at inception of the

contract, including regulatory and sales milestones and sales royalties (see Note 10, Collaboration and Licensing Agreements).

All performance obligations under the Maruishi Agreement and the CKDP Agreement were satisfied by the end of 2015. In the future, any milestone event will be recognized as milestone and license fee revenue and collaboration revenue based upon the relative standalone selling prices of the two performance obligations at inception of the Maruishi Agreement, and as milestone and license fee revenue under the CKDP Agreement.

Under the Maruishi Agreement, the transaction price includes only the non-refundable and non-creditable upfront license fee of $15,337, including the premium of $337 from the sale of Company stock to Maruishi, that was paid to the Company at inception of the contract. The remaining potential consideration was considered to be variable consideration and was constrained at inception of the contract, including an aggregate of up to $10,500, which the Company is eligible to receive upon achievement of clinical development and regulatory milestones, a one-time sales milestone of one billion Yen when a certain sales level is attained; a mid-double-digit percentage of all non-royalty payments received by Maruishi from its sub-licensees, if any; and tiered royalties based on net sales of products containing CR845/difelikefalin in Japan, if any, with minimum royalty rates in the low double digits and maximum royalty rates in the low twenties.

Under the CKDP Agreement, the transaction price includes only the non-refundable and non-creditable upfront license fee of $646, including the premium of $83 from the sale of Company stock to CKDP, that was paid to the Company at inception of the contract. The remaining consideration was considered to be variable consideration and was constrained at inception of the contract, including an aggregate of up to $3,750, which the Company is eligible to earn upon achievement of clinical development and regulatory milestones. The Company is also eligible to receive a mid-double-digit percentage of all non-royalty payments received by CKDP from its sub-licensees, if any, and tiered royalties ranging from the high single digits to the high teens based on net sales of products containing CR845/difelikefalin in South Korea, if any.

Determination of the estimate of the standalone selling price of performance obligations

In order to recognize revenue under ASC 606, as amended, for contracts for which more than one distinct performance obligation has been identified, the Company must allocate the transaction price to the performance obligations based upon their standalone selling prices. The best evidence of standalone selling price is an observable price of a good or service when sold separately by an entity in similar circumstances to similar customers. If such evidence is not available, standalone selling price should be estimated so that the amount that is allocated to each performance obligation equals the amount that the entity expects to receive for transferring goods or services. The Company has identified more than one performance obligation only in the Maruishi Agreement. Since evidence based on observable prices is not available for the performance obligations under the Maruishi Agreement, the Company considered market conditions and entity-specific factors, including those contemplated in negotiating the agreements, as well as certain internally developed estimates.

At inception of the Maruishi Agreement, the Company determined the estimate of standalone selling price for the license performance obligation by using the adjusted market assessment approach. Under this method, the Company forecasted and analyzed CR845/difelikefalin in the Japanese market, the phase of clinical development as well as considered recent similar license arrangements within the same phase of clinical development, therapeutic area, type of agreement, etc. To estimate the standalone selling price of the R&D services, the Company forecasted its expected costs of satisfying that performance obligation and added a margin for that service.

Determination of the method of allocation of the transaction price to the distinct performance obligations

At inception of the Maruishi Agreement, the Company allocated the transaction price of $15,337 between the two performance obligations based on their relative standalone selling prices, determined as described above. The Company determined that the license and the R&D services had estimated standalone selling prices of $10,200 and $6,200, respectively. The resulting percentage allocations were applied to the $15,337 of total transaction price, which resulted in $9,637 being allocated to the license performance obligation, which was recognized immediately as license revenue, while $5,700 was allocated to the R&D services performance obligation. The amount allocated to the R&D services performance obligation was initially recorded as deferred revenue and was recognized as collaborative revenue as the R&D services were provided through July 2015.

Since both the VFMCRP Agreement and the CKDP Agreement each contain only one distinct performance obligation, at the inception of each of those agreements, the entire transaction price was allocated to the respective performance obligation.

Determination of the timing of revenue recognition for contracts

Revenue should be recognized when, or as, an entity satisfies a performance obligation by transferring a promised good or service to a customer; i.e., when the customer obtains control of the good or service. The licenses granted to both Maruishi and CKDP are being accounted for as distinct performance obligations. As discussed below, both licenses relate to functional IP for which revenue is recognized at a point in time – in the case of these two license agreements, the point in time is at inception of the contract because the customer obtained control of the license at that point.

The licenses grant Maruishi and CKDP the right to use the Company’s IP relating to CR845/difelikefalin as it existed at the point in time that the licenses were granted. That IP has significant standalone functionality as it provides the customer with the ability to perform a function or task, such as to manufacture CR845/difelikefalin and conduct clinical trials, and is considered to be functional IP.

During the license periods, the Company is continuing to develop and advance CR845/difelikefalin by conducting clinical trials. Those development efforts are for its own benefit and do not substantively change the significant standalone functionality of the licensed IP granted to Maruishi or CKDP. Therefore, the Company’s ongoing development efforts do not significantly affect the IP’s utility to which Maruishi or CKDP have rights. Furthermore, if the Company abandons its development efforts, Maruishi or CKDP may still continue to develop CR845/difelikefalin in their respective countries.

The R&D services performance obligation under the Maruishi Agreement represents a separate performance obligation. The R&D services were provided to Maruishi by the Company from inception of the agreement in 2013 through the third quarter of 2015, at which time the Company had fulfilled its promise related to the R&D services. Revenue related to the R&D services performance obligation was recognized as services were performed based on the costs incurred as a percentage of the estimated total costs to be incurred to complete the performance obligation.

Similarly, under the VFMCRP Agreement, revenue related to the single distinct performance obligation, which includes both granting of the license and performance of the R&D services, will be recognized as the R&D services are performed, based on the costs incurred as a percentage of the estimated total costs to be incurred to complete the performance obligation. The Company expects that the remaining amount of the transaction price that was allocated to the combined performance obligation of $14,241 at March 31, 2020 will be recognized by 2020, as the R&D services are performed, subject to certain development and regulatory uncertainties.

Determination of consideration as variable consideration, including factors related to inclusion in the transaction price at inception of the contract and timing of recognition as revenue.

The VFMCRP Agreement, the Maruishi Agreement and the CKDP Agreement contain potential payments related to achievement of defined milestone events and royalties upon net sales of future products, which are considered to be variable consideration because of the uncertainty of occurrence of any of those events specified in those agreements at inception of the agreements. Therefore, those potential payments were not included in the transaction price at the inception of the agreements.

Revenue related to achievement of milestone events is recognized when the Company has determined that it is probable that a milestone event will be achieved and there will not be a significant reversal of revenue in future periods. Upon probability of achievement of a milestone event, the most likely amount of variable consideration is included in the transaction price. Subsequent changes to the transaction price, after contract initiation, are allocated to the performance obligations in the contract on the same basis as at contract inception. Revenue for variable consideration is recognized in the same manner (point in time or over time) as for the performance obligations to which the payment amounts were allocated.

The Maruishi Agreement and the CKDP Agreement specify that certain development milestones will be achieved at pre-specified defined phases of a clinical trial (such as initiation or completion or other pre-specified time during a clinical trial as specified in the agreements).

During the three months ended March 31, 2020 and 2019, no milestone events were probable of occurrence or achieved.

Sublicense payments

VFMCRP’s, Maruishi’s and CKDP’s right to grant sub-licenses is explicitly stated in their respective license agreements. The amount of any potential sub-license fees to be received by the Company, which is based on a formula, is considered to be variable consideration and is constrained from inclusion in the transaction price at inception of the contract since at that time it was probable that there would be a reversal of such revenue in the future because the Company did not know if a sublicense would be granted in the future.

Sales-based Royalty Payments

The VFMCRP Agreement, CKDP Agreement and Maruishi Agreement each allow the Company to earn sales-based royalty payments in exchange for a license of intellectual property. In that case, the Company will recognize revenue for a sales-based royalty only when (or as) the later of the following events occurs:

The subsequent sale or usage occurs.

The performance obligation to which some or all of the sales-based royalty has been allocated has been satisfied (or partially satisfied).

Since the sale (item a, above) occurs after the license was delivered (item b, above), the sales-based royalty exception, to exclude such royalty payments from the transaction price, applies to the overall revenue stream. Therefore, sales-based royalty payments are recognized as revenue when the customer’s sales occur. To date, no royalties have been earned or were otherwise due to the Company.

Net Loss Per Share

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Net Loss Per Share

12. Net Loss Per Share

The Company computes basic net income (loss) per share by dividing net income (loss) by the weighted-average number of shares of common stock outstanding. Diluted net income per share includes the potential dilutive effect of common stock equivalents as if such securities were exercised during the period, when the effect is dilutive. Common stock equivalents may include outstanding stock options or restricted stock units, which are included using the treasury stock method when dilutive. For the three months ended March 31, 2020 and 2019, the Company excluded the effects of potentially dilutive shares that were outstanding during those respective periods from the denominator as their inclusion would be anti-dilutive due to the Company’s net losses during those periods.

The denominators used in the net loss per share computations are as follows:


	Three Months Ended
	March 31,
	2020	2019
Basic:
Weighted average common shares outstanding	46,724,951	39,552,277
Diluted:
Weighted average common shares outstanding - Basic	46,724,951	39,552,277
Common stock options*	—	—
Denominator for diluted net loss per share	46,724,951	39,552,277

*	No amounts were considered as their effects would be anti-dilutive.

Basic and diluted net loss per share are computed as follows:


	Three Months Ended
	March 31,
	2020		2019
Net loss	$	(28,922)	$	(21,960)
Weighted-average common shares outstanding:
Basic and Diluted		46,724,951		39,552,277
Net loss per share, Basic and Diluted	$	(0.62)	$	(0.56)

As of March 31, 2020 and 2019, 4,930,590 and 4,925,641 stock options, respectively, were outstanding, which could potentially dilute basic earnings per share in the future, but were not included in the computation of diluted net loss per share because to do so would have been anti-dilutive. In addition, 331,834 unvested restricted stock units issued to executive officers that were outstanding at March 31, 2020 were also not included in the computation of diluted net loss per share because to do so would have been anti-dilutive. The 24,000 restricted stock units granted in June 2019 to the non-employee members of the Board of Directors were also not included in the computation of diluted net loss per share because to do so would have been anti-dilutive (see Note 13, Stock-Based Compensation).

Stock-Based Compensation

3 Months Ended

Mar. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

13. Stock-Based Compensation

2019 Inducement Plan

On October 30, 2019, the Company’s Board of Directors adopted the 2019 Inducement Plan, or the 2019 Plan, which is a non-stockholder approved stock plan adopted pursuant to the “inducement exception” provided under Nasdaq Listing Rule 5635(c)(4), or Rule 5635, for the purpose of awarding (i) non-statutory stock options, (ii) restricted stock awards, (iii) restricted stock unit awards, (iv) other stock awards (collectively, the Inducement Awards) to new employees of the Company, as inducement material to such new employees entering into employment with the Company. On November 20, 2019, the Company filed a Registration Statement on Form S-8 with the SEC covering the offering of up to 300,000 shares of its common stock, par value $0.001, pursuant to the Company’s 2019 Plan. Initial grants of Inducement Awards made to employees vest as to 25% on the first anniversary of the date of grant and the balance ratably over the next 36 months and subsequent grants vest monthly over a period of four years from the grant date.

2014 Equity Incentive Plan

The Company’s 2014 Equity Incentive Plan, or the 2014 Plan, is administered by the Company’s Board of Directors or a duly authorized committee thereof, referred to as the Plan administrator. The 2014 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of equity compensation, collectively referred to as Stock Awards. Additionally, the 2014 Plan provides for the grant of performance cash awards. Incentive stock options may be granted only to employees. All other awards may be granted to employees, including officers, non-employee directors, and consultants. No incentive stock options may be granted under the 2014 Plan after the tenth anniversary of the effective date of the 2014 Plan. Stock Awards granted under the 2014 Plan vest at the rate specified by the Plan administrator. Initial grants of Stock Awards made to employees and non-employee consultants generally vest as to 25% on the first anniversary of the date of grant and the balance ratably over the next 36 months and subsequent grants vest monthly over a period of four years from the grant date. Stock options initially granted to members of the Company’s Board of Directors vest over a period of three years in equal installments from the date of the grant, subject to the option holder’s continued service as a Director through such date. Subsequent grants to Directors that are made automatically at Annual Meetings of Stockholders vest fully on the first anniversary of the date of grant. The Plan administrator determines the term of Stock Awards granted under the 2014 Plan up to a maximum of ten years.

The aggregate number of shares of the Company’s common stock reserved for issuance under the 2014 Plan has automatically increased on January 1 of each year, beginning on January 1, 2015 and will continue to increase on January 1 of each year through and including January 1, 2024, by 3% of the total number of shares of the Company’s capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s Board of Directors. On January 1, 2020, the aggregate number of shares of common stock that may be issued pursuant to Stock Awards under the 2014 Plan automatically increased from 6,086,907 to 7,488,513. The maximum number of shares that may be issued pursuant to the exercise of incentive stock options under the 2014 Plan is 30,000,000 shares.

Restricted Stock Units

In February 2020, the Compensation Committee of the Company’s Board of Directors approved and granted a total of 138,000 restricted stock units to executive officers under the 2014 Plan with a grant date fair value of $16.36 per share. Vesting of the restricted stock units is contingent on the achievement of certain performance targets related to the results of ongoing clinical trials, NDA filing and FDA approval as well as the recipient’s continuous service through

each performance target. At the date of grant, the Company concluded that the probability of achievement of the performance targets could not be determined until the various milestones were probable of being achieved, and accordingly, the Company did not recognize any compensation expense during the three months ended March 31, 2020. Recognition of compensation expense associated with these awards begins when, and to the extent, the performance criteria have been achieved and therefore, the restricted stock units are earned and vesting has occurred.

Additionally in February 2020, the Compensation Committee of the Company’s Board of Directors also approved and granted a total of 98,000 time-based restricted stock units to executive officers under the 2014 Plan with a grant date fair value of $16.36 per share. The restricted stock units vest in three equal installments annually from the date of the grant. As a result, the Company will recognize compensation expense associated with these restricted stock units ratably over the three-year vesting period following the grant date. For the three months ended March 31, 2020, $44 of stock compensation expense was recognized in the Statement of Comprehensive Loss, consisting of $14 relating to R&D expense and $30 relating to G&A expense. None of the 98,000 restricted stock units vested or were settled in shares of the Company’s common stock as of March 31, 2020.

In June 2019, the Board of Directors, upon the recommendation of the Compensation Committee, amended the Company’s non-employee director compensation policy. Pursuant to the terms of the amended policy, each non-employee director was entitled to receive, at the time of the Company’s 2019 Annual Meeting of Stockholders, 6,000 restricted stock units. As a result, on June 4, 2019, the date of the Company’s 2019 Annual Meeting of Stockholders, an aggregate of 24,000 restricted stock units were granted to Directors under the 2014 Plan with a grant date fair value of $20.47 per share. The restricted stock units vest on the earlier of (i) June 4, 2020 and (ii) immediately prior to the Company’s next Annual Meeting of Stockholders following the grant date, subject to the recipient’s continued service through such date. As a result, the Company will recognize compensation expense associated with these restricted stock units ratably over the one-year vesting period following the grant date. For the three months ended March 31, 2020, $123 of stock compensation expense relating to the Board of Directors’ restricted stock units was recognized in the Statements of Comprehensive Loss, all of which related to G&A expense. None of the 24,000 restricted stock units vested or were settled in shares of the Company’s common stock as of March 31, 2020.

In March 2019, the Compensation Committee of the Company’s Board of Directors approved and granted a total of 215,000 restricted stock units to executive officers under the 2014 Plan with a grant date fair value of $16.10 per share. Vesting of the restricted stock units is contingent on the achievement of certain performance targets related to the results of ongoing clinical trials, subject to the recipient’s continuous service through the vesting events. At the date of grant, the Company concluded that the probability of achievement of the performance targets could not be determined until the milestones were probable of being achieved, and accordingly, the Company would recognize compensation expense associated with these awards when, and to the extent, the restricted stock units vested in accordance with achievement of the performance targets. As of March 31, 2020, 95,834 restricted stock units remain unvested since various performance targets have not yet been achieved. During the three months ended March 31, 2020 and 2019, no stock compensation expense relating to the vesting of these restricted stock units was recognized in the Statements of Comprehensive Loss since none of the restricted stock units had vested during the respective periods.

Stock Options

Under the 2014 Plan, the Company granted 673,350 and 957,000 stock options during the three months ended March 31, 2020 and 2019, respectively. No stock options were granted under the 2019 Inducement Plan during the three months ended March 31, 2020. The fair values of stock options granted during the three months ended March 31, 2020 and 2019 were estimated as of the dates of grant using the Black-Scholes option pricing model with the following assumptions:


	Three Months Ended
	March 31,
	2020	2019
Risk-free interest rate	0.54% - 1.57%	2.54% - 2.62%
Expected volatility	73.72% - 74.71%	74.29% - 75.19%
Expected dividend yield	0%	0%
Expected life of employee options (in years)	6.25	6.25
Expected life of non-employee options (in years)	—	—

The weighted-average grant date fair value per share of options granted to employees during the three months ended March 31, 2020 and 2019 was $10.59 and $10.83, respectively. No options were granted to non-employee members of the Company’s Board of Directors for their Board service or to non-employee consultants during the three months ended March 31, 2020 and 2019.

On January 1, 2019, the Company used the Black-Scholes option valuation model to remeasure the fair value of all outstanding unvested options that had been granted to non-employee consultants in accordance with ASU 2018-07, Compensation – Stock Compensation (Topic 718), Improvements to Non-employee Share-Based Payment Accounting. The range of assumptions used by the Company on January 1, 2019 were as follows:



		January 1, 2019
Risk-free interest rate		2.59% - 2.62%
Expected volatility		58.9% - 84.6%
Expected dividend yield		0%
Expected life of non-employee options (in years)		0.81 - 8.19

During the three months ended March 31, 2020 and 2019, the Company recognized compensation expense relating to stock options as follows:


	Three Months Ended
	March 31,
	2020		2019
Research and development	$	1,609	$	1,082
General and administrative		1,070		1,152
Total stock option expense	$	2,679	$	2,234

The following were excluded from the table above as they are not related to stock options: compensation expense for i) the vesting of executives’ restricted stock units for $14 in R&D expense and $30 in G&A expense for the three months ended March 31, 2020; and ii) compensation expense relating to the Board of Directors’ restricted stock units for $123 in G&A expense for the three months ended March 31, 2020.

A summary of stock option award activity related to employees, non-employee members of the Company’s Board of Directors and non-employee consultants as of and for the three months ended March 31, 2020 is presented below:


		Weighted		Aggregate
	Number of	Average Exercise		Intrinsic
	Shares	Price		Value
Outstanding, December 31, 2019	4,450,517	$	14.73
Granted	673,350		16.11
Exercised	(7,500)		9.94
Expired	(161,089)		13.64
Forfeited	(24,688)		16.51
Outstanding, March 31, 2020	4,930,590	$	14.95	$	5,099
Weighted average remaining contractual life as of March 31, 2020 (in years)	7.68
Options exercisable, March 31, 2020	2,484,710	$	13.10	$	4,763
Weighted average remaining contractual life as of March 31, 2020 (in years)	6.47
Options vested and expected to vest as of March 31, 2020	4,930,590	$	14.95	$	5,099
Weighted average remaining contractual life as of March 31, 2020 (in years)	7.68

The Company does not expect to realize any tax benefits from its stock option activity or the recognition of stock-based compensation expense because the Company currently has net operating losses and has a full valuation allowance against its deferred tax assets. Accordingly, no amounts related to excess tax benefits have been reported in cash flows from operations for the three months ended March 31, 2020 and 2019.

Commitments and Contingencies

3 Months Ended

Mar. 31, 2020

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

15. Commitments and Contingencies

License Agreement with Enteris Biopharma, Inc.

On August 20, 2019, the Company entered into the Enteris License Agreement with Enteris Biopharma, Inc., or Enteris, pursuant to which Enteris granted to the Company a non-exclusive, royalty-bearing license, including the right to grant sublicenses, under certain proprietary technology and patent rights related to or covering formulations for oral delivery of peptide active pharmaceutical ingredients with functional excipients to enhance permeability and/or solubility, known as Enteris’s Peptelligence^® technology, to develop, manufacture and commercialize products using such technology worldwide, excluding Japan and South Korea.

As consideration for the licensed rights under the Enteris License Agreement, the Company paid an upfront fee equal to $8,000, consisting of $4,000 in cash and $4,000 in shares of the Company’s common stock pursuant to the Purchase Agreement with Enteris, or the Purchase Agreement.

The Company is also obligated, pursuant to the Enteris License Agreement, to pay Enteris (1) milestone payments upon the achievement of certain development, regulatory and commercial milestones and (2) low-single digit royalty percentages on net sales of licensed products, subject to reductions in specified circumstances. Until the second anniversary of the entry into the Enteris License Agreement, the Company has the right, but not the obligation, to terminate its obligation to pay any royalties under the Enteris License Agreement in exchange for a lump sum payment in cash, or the Royalty Buyout. Subject to certain conditions, the Company may elect to pay 50% of the lump sum due under the Royalty Buyout in shares of the Company’s common stock pursuant to the Purchase Agreement. During the three months ended March 31, 2020, no milestone payments or royalties were paid to Enteris by the Company.

The Enteris License Agreement will expire on a country-by-country, licensed product-by-licensed product basis upon the later of (1) the expiration (or invalidation) of all valid claims in licensed patent rights that cover such product in such country, (2) the end of the calendar quarter in which generic competition (as defined in the Enteris License Agreement) occurs for such product in such country and (3) ten years from the first commercial sale of such product.

Either party may terminate the Enteris License Agreement upon written notice if the other party has failed to remedy a material breach within 60 days (or 30 days in the case of a material breach of a payment obligation). Enteris may terminate the Enteris License Agreement upon 30 days’ written notice to the Company if the Company or any of its affiliates formally challenge the validity of any licensed patent rights or assists a third party in doing so. The Company may terminate the Enteris License Agreement for any reason or no reason (a) prior to receipt of first regulatory approval for a licensed product in the United States for any indication upon 30 days’ prior written notice to Enteris or (b) on or after receipt of first regulatory approval for a licensed product in the United States for any indication upon 60 days’ prior written notice to Enteris.

Manufacturing Agreement

On July 8, 2019, the Company entered into a Master Manufacturing Services Agreement, or MSA, with Patheon UK Limited, or Patheon. The MSA governs the general terms under which Patheon, or one of its affiliates, will provide non-exclusive manufacturing services to the Company for the drug products specified by the Company from time to time. Pursuant to the MSA, the Company has agreed to order from Patheon at least a certain percentage of its commercial requirements for a product under a related Product Agreement. Each Product Agreement that the Company may enter into from time to time will be governed by the terms of the MSA, unless expressly modified in such Product Agreement.

The MSA has an initial term ending December 31, 2023, and will automatically renew after the initial term for successive terms of two years each if there is a Product Agreement in effect, unless either party gives notice of its intention to terminate the MSA at least 18 months prior to the end of the then current term.

Either party may terminate the MSA or a Product Agreement upon written notice if the other party (1) has failed to remedy a material breach within a specified time or (2) is declared insolvent or bankrupt, voluntarily files a petition of bankruptcy or assigns such agreement for the benefit of creditors. The Company may terminate a Product Agreement (a) upon 90 days’ prior written notice if any governmental agency takes any action that prevents the Company from selling the relevant product in the relevant territory, (b) upon six months’ prior written notice if it does not intend to order manufacturing services due to a product’s discontinuance in the market, or (c) upon 90 days’ prior written notice if it determines that the manufacture or supply of a product likely infringes third-party rights. Patheon may terminate the MSA or a Product Agreement (i) upon six months’ prior written notice if the Company assigns such agreement to an assignee that is unacceptable to Patheon for certain reasons, or (ii) upon 30 days’ prior written notice if, after the first year of commercial sales, the Company forecasts zero volume for 12 months.

The MSA contains, among other provisions, customary representations and warranties by the parties, a grant to Patheon of certain limited license rights to the Company’s intellectual property in connection with Patheon’s performance of the services under the MSA, certain indemnification rights in favor of both parties, limitations of liability and customary confidentiality provisions.

On July 8, 2019, and July 9, 2019, the Company entered into two related Product Agreements under the MSA, one with each of Patheon and Patheon Manufacturing Services LLC, or Patheon Greenville, to govern the terms and conditions of the manufacture of commercial supplies of CR845/difelikefalin injection, the Company’s lead product candidate. Pursuant to the Product Agreements, Patheon and Patheon Greenville will manufacture commercial supplies of CR845/difelikefalin injection at the Monza, Italy and Greenville, North Carolina manufacturing sites, respectively, from active pharmaceutical ingredient supplied by the Company. Patheon and Patheon Greenville will be responsible for supplying the other required raw materials and packaging components, and will also provide supportive manufacturing services such as quality control testing for raw materials, packaging components and finished product.

Leases

In December 2015, the Company entered into a lease agreement, or the Stamford Lease, for office space in Stamford, Connecticut, or the Premises, for the purposes of relocating its headquarters. The initial term of the Stamford Lease commenced in May 2016, or the Commencement Date, and ends in November 2023 and is renewable for one five-year term.

The Stamford Lease requires monthly lease payments, including rent escalations and rent holidays, during the initial lease term. The Company began to make rental payments from the Commencement Date. As of the Commencement Date, the Stamford Lease landlord had made tenant improvements of $1,094 to the leased premises which was included in Property and equipment, net.

In connection with the signing of the Stamford Lease, the Company entered into a standby letter of credit agreement which serves as a security deposit for the Premises. The standby letter of credit is automatically renewed annually through November 2023. This standby letter of credit is secured with restricted cash in a money market account (refer to Note 6, Restricted Cash).

On January 1, 2019, the Company adopted ASC 842: Leases, or ASC 842. Under ASC 842, since the Company adopted the practical expedients not to re-evaluate whether a contract is or contains a lease and to maintain the lease classification under ASC 840, the Stamford Lease continues to be accounted for as an operating lease.

Upon adoption of ASC 842, the Company was required to establish an operating lease ROU asset and operating lease liability for the Stamford Lease. In establishing the ROU asset, the operating lease liability of $5,198 was reduced by lease incentives relating to tenant improvements of $698 and deferred lease obligation of $864, which were outstanding upon adoption.

Under ASC 842, lease expense is recognized on a straight-line basis over the lease term. As a result, $234 of operating lease cost, or lease expense, was recognized in the Company’s Condensed Statements of Comprehensive Loss for each of the three months ended March 31, 2020 and 2019, consisting of $164 relating to R&D lease expense and $70 relating to G&A lease expense.

Other information related to the Stamford Lease was as follows:


	Three Months Ended			Three Months Ended
	March 31, 2020			March 31, 2019
Cash paid for amounts included in the measurement of lease liability:
Operating cash outflows relating to operating lease	$	306		$	300
ROU assets obtained in exchange for new operating lease liabilities	$	—		$	3,636
Remaining lease term - operating lease (years)		3.7			4.7
Discount rate - operating lease		7.0	%		7.0	%

Future minimum lease payments under non-cancellable operating leases, as well as a reconciliation of these undiscounted cash flows to the operating lease liability as of March 31, 2020, were as follows:


Year Ending December 31,
2020 (Excluding the three months ended March 31, 2020)	$	933
2021		1,264
2022		1,288
2023		1,164
2024		—
Total future minimum lease payments, undiscounted		4,649
Less imputed interest		(562)
Total	$	4,087

Operating lease liability reported as of March 31, 2020:
Operating lease liability - current	$	991
Operating lease liability - non-current		3,096
Total	$	4,087

Basis of Presentation (Policies)	3 Months Ended
Basis of Presentation (Policies)	Mar. 31, 2020
Basis of Presentation
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, as of the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Significant estimates include the fair value of marketable securities that are classified as level 2 of the fair value hierarchy, useful lives of fixed assets, the periods over which certain revenues will be recognized, including licensing and collaborative revenue recognized from non-refundable up-front and milestone payments, the determination of prepaid research and development, or R&D, clinical costs and accrued research projects, the amount of non-cash compensation costs related to share-based payments to employees and non-employees and the periods over which those costs are expensed, the incremental borrowing rate used in lease calculations and the likelihood of realization of deferred tax assets. The COVID-19 pandemic is expected to result in a slowdown of economic activity that is likely to interrupt business operations across the globe. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these condensed financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the reported amounts of assets and liabilities or the disclosure of contingent assets and liabilities. These estimates, however, may change as new events occur and additional information is obtained, and are recognized in the condensed financial statements as soon as they become known. Actual results could differ materially from the Company’s estimates and assumptions.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes to the significant accounting policies previously disclosed in Note 2 to the Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, except for the recent adoption of new accounting pronouncements as disclosed below.
Recent Accounting Pronouncements	Accounting Pronouncements Recently Adopted On January 1, 2020, the Company adopted Accounting Standards Update, or ASU, No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, or ASU 2016-13, which replaces the incurred loss impairment methodology in prior GAAP that delays recognition of a credit loss until it is probable that such loss has been incurred, with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The Company deems certain of its investments to be marketable securities if the investment, or in the case of money market funds, the securities underlying the money market fund, meet the definition of a debt security in Accounting Standards Codification, or ASC, section 320-10-20. The Company considers its marketable securities to be available-for-sale, which are its only financial instruments that are within the scope of ASU 2016-13 as of March 31, 2020. The Company’s investments in marketable securities, including U.S. Treasury securities, U.S. government agency obligations, corporate bonds, commercial paper and municipal bonds, are highly rated by Moody’s and S&P and have maturities primarily of less than one year but no longer than two years. Accordingly, credit risk associated with the Company’s available-for-sale debt security portfolio is mitigated. ASU 2016-13 modifies the prior other-than-temporary impairment model for available-for-sale debt securities by requiring (1) estimating expected credit losses (the portion of the amortized cost basis of a financial asset that the Company does not expect to collect) only when the fair value is below the amortized cost of the asset; (2) recording a credit loss without regard to the length of time a security has been in an unrealized loss position; (3) limiting the measurement of the credit loss to the difference between the security’s amortized cost basis and its fair value; and (4) presenting credit losses as an allowance rather than as a write-down, which will allow the Company to record reversals of credit losses in current period net income, a practice that was previously prohibited. In April and November 2019, respectively, codification improvements were issued to help clarify and correct certain portions of ASU 2016-13. The Company reviews each of its available-for-sale marketable securities for unrealized losses (declines in fair value below its amortized cost basis) at each balance sheet date presented in its financial statements and whenever events or changes in circumstances indicate that the amortized cost basis of an asset may not be recoverable. In accordance with the adoption of ASU 2016-13, the Company is required to determine whether any portion of the unrealized loss for any available-for-sale debt security is due to a credit loss, and if so, to measure the amount of the credit loss. The Company will rely on both qualitative and quantitative factors to determine whether the unrealized loss for each available-for-sale debt security at any balance sheet date is due to a credit loss. Qualitative factors may include a credit downgrade, severity of the decline in fair value below amortized cost and other adverse conditions related specifically to the security, as well as the intent to sell the security, or whether the Company will more likely than not be required to sell the security before recovery of its amortized cost basis. The Company’s assessment of whether a security is impaired could change in the future due to new developments or changes in assumptions related to any particular security. If material qualitative factors indicate that a credit loss has occurred, the Company will determine the magnitude of that credit loss using a discounted cash flow model or other quantitative method. If the Company intends to sell the security or it is more likely than not that the Company will be forced to sell the security before recovery of the amortized cost of the security, the entire unrealized loss is deemed to be a credit loss, which is recognized in net income (loss). Otherwise, the portion of the unrealized loss that is due to a credit loss will be recorded as an Allowance for Credit Loss, which will offset the balance of Marketable Securities on the Condensed Balance Sheets and as credit loss expense within other income, net on the Condensed Statements of Comprehensive Loss. The portion of the unrealized loss that is not due to a credit loss as well as all unrealized gains will be recorded in Accumulated Other Comprehensive Income (Loss), or AOCI, net of taxes, on the Condensed Balance Sheets. There was no cumulative effect adjustment as a result of the adoption of ASU 2016-13 on January 1, 2020 (see Note 3, Available-for-Sale Marketable Securities, and Note 5, Fair Value Measurements). Accrued interest receivables are excluded from the Company’s amortized cost bases for its available-for-sale marketable securities and are included within Other Receivables on the Company’s Condensed Balance Sheets. The Company’s policy is to not measure an allowance for credit losses on accrued interest receivable balances at each reporting period since it elects to write off uncollectible accrued interest receivable balances as credit loss expense in a timely manner, which is by maturity date for all categories of its debt securities. On January 1, 2020, the Company adopted ASU 2019-08, Compensation – Stock Compensation (Topic 718) and Revenue from Contracts with Customers (Topic 606), or ASU 2019-08, which requires the Company to measure and classify share-based payment awards granted to a customer by applying the guidance in Topic 718. The amount recorded as a reduction to the transaction price is required to be measured on the basis of the grant-date fair value of the share-based payment award in accordance with Topic 718. The grant date is the date at which a grantor (supplier) and a grantee (customer) reach a mutual understanding of the key terms and conditions of a share-based payment award. The classification and subsequent measurement of the award are subject to the guidance in Topic 718 unless the share-based payment award is subsequently modified and the grantee is no longer a customer. The adoption of ASU 2019-08 did not have a material effect on its results of operations, financial position or cash flows since the Company has not historically granted share-based payment awards to customers. On January 1, 2020, the Company adopted ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, or ASU 2018-18, which clarifies the interaction between Topic 808 and Topic 606 by (1) clarifying that certain transactions between collaborative arrangement participants should be accounted for under Topic 606; (2) adding unit-of-account guidance in Topic 808 to align with the guidance in Topic 606; and (3) clarifying presentation guidance for transactions with a collaborative arrangement participant that are not accounted for under Topic 606. The adoption of ASU 2018-18 did not have any effect on its financial position, results of operations or cash flows since all three of its collaboration and licensing agreements are accounted for under Topic 606 (see Note 10, Collaboration and Licensing Agreements and Note 11, Revenue Recognition). On January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, or ASU 2018-13, which modifies the disclosure requirements on fair value measurements in Topic 820 to remove the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements. ASU 2018-13 also amends Topic 820 to clarify that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. ASU 2018-13 also requires additional disclosure for changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period as well as the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. Upon adoption of ASU 2018-13, the Company did not have any assets or liabilities that are included in Level 3 fair value measurements and no retrospective treatment was applicable. As a result, the adoption of ASU 2018-13 did not have a material effect on its results of operations, financial position or cash flows. Accounting Pronouncements Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740), or ASU 2019-12, which removes specific exceptions to the general principles in Topic 740. ASU 2019-12 eliminates the need for an organization to analyze whether the following apply in a given period: i) exception to the incremental approach for intra-period tax allocation; ii) exceptions to accounting for basis differences when there are ownership changes in foreign investments; and iii) exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss. ASU 2019-12 also simplifies the accounting for income taxes for: i) franchise taxes that are partially based on income; ii) transactions with a government that result in a step up in the tax basis of goodwill; (iii) separate financial statements of legal entities that are not subject to tax; and iv) enacted changes in tax laws in interim periods. The amendments in ASU 2019-12 are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of the amendments is permitted. An entity that elects to early adopt the amendments in an interim period should reflect any adjustments as of the beginning of the annual period that includes that interim period and must adopt all the amendments in the same period. The amendments in ASU 2019-12 related to separate financial statements of legal entities that are not subject to tax should be applied on a retrospective basis for all periods presented. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The amendments related to franchise taxes that are partially based on income should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. All other amendments should be applied on a prospective basis. As such, the Company expects to adopt ASU 2019-12 on January 1, 2021 and is currently evaluating the effect it will have on its results of operations, financial position and cash flows.

Available-for-Sale Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2020

Investments Debt And Equity Securities [Abstract]

Summary of Available-for-Sale Marketable Securities by Major Type of Security

The following tables summarize the Company’s available-for-sale marketable securities by major type of security as of March 31, 2020 and December 31, 2019:

As of March 31, 2020


			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	16,065	$	249	$	—	$	16,314
U.S. government agency obligations		17,601		39		(1)		17,639
Corporate bonds		93,681		79		(460)		93,300
Commercial paper		31,949		26		—		31,975
Municipal bonds		3,500		—		—		3,500
Total available-for-sale marketable securities	$	162,796	$	393	$	(461)	$	162,728

As of December 31, 2019


			Gross Unrealized				Estimated Fair
Type of Security	Amortized Cost		Gains		Losses		Value
U.S. Treasury securities	$	16,052	$	31	$	(2)	$	16,081
U.S. government agency obligations		25,803		14		(1)		25,816
Corporate bonds		115,788		125		(23)		115,890
Commercial paper		38,547		27		(1)		38,573
Municipal bonds		3,500		—		—		3,500
Total available-for-sale marketable securities	$	199,690	$	197	$	(27)	$	199,860

Schedule of Fair Values and Continuous Unrealized Loss Positions of Available-for-Sale Marketable Securities

As of March 31, 2020


	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. government agency obligations	$	4,248	$	(1)	$	—	$	—	$	4,248	$	(1)
Corporate bonds		63,046		(460)		—		—		63,046		(460)
Total	$	67,294	$	(461)	$	—	$	—	$	67,294	$	(461)

As of December 31, 2019


	Less than 12 Months				12 Months or Greater				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury securities	$	3,185	$	(2)	$	—	$	—	$	3,185	$	(2)
U.S. government agency obligations		2,400		(1)		—		—		2,400		(1)
Corporate bonds		28,895		(23)		—		—		28,895		(23)
Commercial paper		4,264		(1)		—		—		4,264		(1)
Total	$	38,744	$	(27)	$	—	$	—	$	38,744	$	(27)

Schedule of Amortized Cost and Fair Values of Marketable Debt Securities by Contractual Maturity


	As of March 31, 2020				As of December 31, 2019
Contractual maturity	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than one year	$	103,142	$	103,160	$	136,565	$	136,701
One year to two years		59,654		59,568		63,125		63,159
Total	$	162,796	$	162,728	$	199,690	$	199,860

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on Recurring Basis

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019.

Fair value measurement as of March 31, 2020:


			Quoted prices in		Significant other		Significant
Financial assets			active markets for		observable		unobservable
			identical assets		inputs		inputs
Type of Instrument	Total		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents:
Money market funds and checking accounts	$	17,036	$	17,036	$	—	$	—
Available-for-sale marketable securities:
U.S. Treasury securities		16,314		—		16,314		—
U.S. government agency obligations		17,639		—		17,639		—
Corporate bonds		93,300		—		93,300		—
Commercial paper		31,975		—		31,975		—
Municipal bonds		3,500		—		3,500		—
Restricted cash:
Commercial money market account		408		408		—		—
Total financial assets	$	180,172	$	17,444	$	162,728	$	—

Fair value measurement as of December 31, 2019:


			Quoted prices in		Significant other		Significant
Financial assets			active markets for		observable		unobservable
			identical assets		inputs		inputs
Type of Instrument	Total		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents:
Money market funds and checking accounts	$	18,305	$	18,305	$	—	$	—
Available-for-sale marketable securities:
U.S. Treasury securities		16,081		—		16,081		—
U.S. government agency obligations		25,816		—		25,816		—
Corporate bonds		115,890		—		115,890		—
Commercial paper		38,573		—		38,573		—
Municipal bonds		3,500		—		3,500		—
Restricted cash:
Commercial money market account		408		408		—		—
Total financial assets	$	218,573	$	18,713	$	199,860	$	—

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Computation of Denominators Used in Net Loss per Share

The denominators used in the net loss per share computations are as follows:


	Three Months Ended
	March 31,
	2020	2019
Basic:
Weighted average common shares outstanding	46,724,951	39,552,277
Diluted:
Weighted average common shares outstanding - Basic	46,724,951	39,552,277
Common stock options*	—	—
Denominator for diluted net loss per share	46,724,951	39,552,277

*	No amounts were considered as their effects would be anti-dilutive.

Computation of Basic and Diluted Net Loss per Share

Basic and diluted net loss per share are computed as follows:


	Three Months Ended
	March 31,
	2020		2019
Net loss	$	(28,922)	$	(21,960)
Weighted-average common shares outstanding:
Basic and Diluted		46,724,951		39,552,277
Net loss per share, Basic and Diluted	$	(0.62)	$	(0.56)

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Summary of Assumptions Used in Black-Scholes Option Pricing Model


	Three Months Ended
	March 31,
	2020	2019
Risk-free interest rate	0.54% - 1.57%	2.54% - 2.62%
Expected volatility	73.72% - 74.71%	74.29% - 75.19%
Expected dividend yield	0%	0%
Expected life of employee options (in years)	6.25	6.25
Expected life of non-employee options (in years)	—	—

Summary of Compensation Expense Relating to Stock Options

During the three months ended March 31, 2020 and 2019, the Company recognized compensation expense relating to stock options as follows:


	Three Months Ended
	March 31,
	2020		2019
Research and development	$	1,609	$	1,082
General and administrative		1,070		1,152
Total stock option expense	$	2,679	$	2,234

Summary of Stock Option Activity


		Weighted		Aggregate
	Number of	Average Exercise		Intrinsic
	Shares	Price		Value
Outstanding, December 31, 2019	4,450,517	$	14.73
Granted	673,350		16.11
Exercised	(7,500)		9.94
Expired	(161,089)		13.64
Forfeited	(24,688)		16.51
Outstanding, March 31, 2020	4,930,590	$	14.95	$	5,099
Weighted average remaining contractual life as of March 31, 2020 (in years)	7.68
Options exercisable, March 31, 2020	2,484,710	$	13.10	$	4,763
Weighted average remaining contractual life as of March 31, 2020 (in years)	6.47
Options vested and expected to vest as of March 31, 2020	4,930,590	$	14.95	$	5,099
Weighted average remaining contractual life as of March 31, 2020 (in years)	7.68

Share-based Payment Arrangement, Nonemployee [Member] | Consultants [Member] | Re-Measurement [Member]

Summary of Assumptions Used in Black-Scholes Option Pricing Model



		January 1, 2019
Risk-free interest rate		2.59% - 2.62%
Expected volatility		58.9% - 84.6%
Expected dividend yield		0%
Expected life of non-employee options (in years)		0.81 - 8.19

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2020

Commitments And Contingencies Disclosure [Abstract]

Schedule of Other Information related to Stamford Lease

Other information related to the Stamford Lease was as follows:


	Three Months Ended			Three Months Ended
	March 31, 2020			March 31, 2019
Cash paid for amounts included in the measurement of lease liability:
Operating cash outflows relating to operating lease	$	306		$	300
ROU assets obtained in exchange for new operating lease liabilities	$	—		$	3,636
Remaining lease term - operating lease (years)		3.7			4.7
Discount rate - operating lease		7.0	%		7.0	%

Schedule of Future Minimum Lease Payments under Non-cancellable Operating Leases, Reconciliation of Undiscounted Cash Flows to the Operating Lease Liability


Year Ending December 31,
2020 (Excluding the three months ended March 31, 2020)	$	933
2021		1,264
2022		1,288
2023		1,164
2024		—
Total future minimum lease payments, undiscounted		4,649
Less imputed interest		(562)
Total	$	4,087

Operating lease liability reported as of March 31, 2020:
Operating lease liability - current	$	991
Operating lease liability - non-current		3,096
Total	$	4,087

Business - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 31, 2018	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Nature Of Business [Line Items]
Date of formation		Jul. 02, 2004
Proceeds from equity and debt financing		$ 519,600
Upfront and milestone payments received in connection with license agreements		89,000
Unrestricted cash and cash equivalents and marketable securities		179,764
Accumulated deficit		429,649		$ 400,727
Net loss		28,922	$ 21,960
Net cash used in operating activities		$ (38,303)	$ (27,526)
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Nature Of Business [Line Items]
Proceeds from sale of common stock in connection with license agreement	$ 14,556
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Common Stock [Member]
Nature Of Business [Line Items]
Common stock, shares issued	1,174,827

Available-for-Sale Marketable Securities - Schedule of Fair Values and Continuous Unrealized Loss Positions of Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Fair Value	$ 67,294	$ 38,744
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Gross Unrealized Losses	(461)	(27)
Available-for-sale marketable securities, continuous unrealized loss position, 12 Months or Greater, Gross Unrealized Losses	0	0
Available-for-sale marketable securities, continuous unrealized loss position, Fair Value	67,294	38,744
Available-for-sale marketable securities, continuous unrealized loss position, Gross Unrealized Losses	(461)	(27)
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Fair Value		3,185
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Gross Unrealized Losses		(2)
Available-for-sale marketable securities, continuous unrealized loss position, Fair Value		3,185
Available-for-sale marketable securities, continuous unrealized loss position, Gross Unrealized Losses		(2)
U.S. Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Fair Value	4,248	2,400
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Gross Unrealized Losses	(1)	(1)
Available-for-sale marketable securities, continuous unrealized loss position, Fair Value	4,248	2,400
Available-for-sale marketable securities, continuous unrealized loss position, Gross Unrealized Losses	(1)	(1)
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Fair Value	63,046	28,895
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Gross Unrealized Losses	(460)	(23)
Available-for-sale marketable securities, continuous unrealized loss position, Fair Value	63,046	28,895
Available-for-sale marketable securities, continuous unrealized loss position, Gross Unrealized Losses	$ (460)	(23)
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Fair Value		4,264
Available-for-sale marketable securities, continuous unrealized loss position, Less than 12 Months, Gross Unrealized Losses		(1)
Available-for-sale marketable securities, continuous unrealized loss position, Fair Value		4,264
Available-for-sale marketable securities, continuous unrealized loss position, Gross Unrealized Losses		$ (1)

Available-for-Sale Marketable Securities - Schedule of Amortized Cost and Fair Values of Marketable Debt Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Amortized Cost of marketable debt securities, contractual maturity, Less than one year	$ 103,142		$ 136,565
Amortized Cost of marketable debt securities, contractual maturity, One year to two years	59,654		63,125
Amortized Cost	162,796		199,690
Fair value of marketable debt securities, contractual maturity, Less than one year	103,160		136,701
Fair value of marketable debt securities, contractual maturity, One year to two years	59,568		63,159
Total fair Value of marketable debt securities, contractual maturity	162,728		199,860
Proceeds from sale of available-for-sale marketable securities	0	$ 0
Interest receivable	$ 847		$ 971

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial assets
Available-for-sale marketable securities	$ 162,728	$ 199,860
Recurring [Member]
Financial assets
Total financial assets	180,172	218,573
U.S. Government Agency Obligations [Member]
Financial assets
Available-for-sale marketable securities	17,639	25,816
U.S. Government Agency Obligations [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	17,639	25,816
Corporate Bonds [Member]
Financial assets
Available-for-sale marketable securities	93,300	115,890
Corporate Bonds [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	93,300	115,890
Municipal Bonds [Member]
Financial assets
Available-for-sale marketable securities	3,500	3,500
Municipal Bonds [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	3,500	3,500
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring [Member]
Financial assets
Total financial assets	17,444	18,713
Significant Other Observable Inputs (Level 2) [Member] \| Recurring [Member]
Financial assets
Total financial assets	162,728	199,860
Significant Other Observable Inputs (Level 2) [Member] \| U.S. Government Agency Obligations [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	17,639	25,816
Significant Other Observable Inputs (Level 2) [Member] \| Corporate Bonds [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	93,300	115,890
Significant Other Observable Inputs (Level 2) [Member] \| Municipal Bonds [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	3,500	3,500
Money Market Funds [Member] \| Recurring [Member]
Financial assets
Cash and cash equivalents	17,036	18,305
Restricted cash	408	408
Money Market Funds [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Recurring [Member]
Financial assets
Cash and cash equivalents	17,036	18,305
Restricted cash	408	408
U.S. Treasury Securities [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	16,314	16,081
U.S. Treasury Securities [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	16,314	16,081
Commercial Paper [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	31,975	38,573
Commercial Paper [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Recurring [Member]
Financial assets
Available-for-sale marketable securities	$ 31,975	$ 38,573

Collaboration and Licensing Agreements - Additional Information (Detail) $ / shares in Units, $ in Thousands		3 Months Ended
	May 17, 2018 USD ($) item $ / shares shares	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer		$ 8,093	$ 4,382
Clinical Compound Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer		$ 72	140
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable, non-creditable upfront payment	$ 50,000
Common stock, shares issued \| shares	1,174,827
Purchase of common stock value	$ 20,000
Purchase common stock per share amount \| $ / shares	$ 17.024
Closing prices of company common stock description	over a pre-determined average closing price of the Company’s common stock
Premium from sale of stock	$ 5,444
Contract liabilities	$ 55,444
Number of combined performance obligations for revenue recognized \| item	1
Number of days to terminate agreement		60 days
Termination notice effective period		12 months
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Regulatory and Commercial Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments receivable	$ 470,000
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments receivable	30,000
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Tiered Commercial Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments receivable	$ 440,000
Maruishi Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cost of clinical compound related to R&D expense		$ 65	126
Maruishi Pharmaceutical Co., Ltd. [Member] \| Clinical Compound Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer		$ 72	$ 140

Revenue Recognition - Additional Information (Detail) ¥ in Billions		1 Months Ended		3 Months Ended
	May 17, 2018 USD ($) item	Apr. 30, 2013 USD ($) item	Apr. 30, 2012 USD ($)	Mar. 31, 2020 USD ($) item Milestone	Mar. 31, 2019 USD ($) Milestone	Dec. 31, 2019 USD ($)	Apr. 30, 2013 JPY (¥)
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue, current				$ 14,241,000		$ 22,262,000
Deferred revenue, non current				0
Total revenue				$ 8,093,000	$ 4,382,000
Number of milestone event probable of occurrence or achieved \| Milestone				0	0
License and Milestone Fees [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Total revenue				$ 8,021,000	$ 4,242,000
Royalty [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue from contract with customer				0
VFMCRP Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue, current				14,241,000		22,262,000
Receivables				0
Other assets						0
Deferred revenue	$ 55,444,000
Number of combined performance obligations for revenue recognized \| item	1
Number of performance obligations for revenue recognized \| item	2
upfront payment	$ 50,000,000
Premium from sale of stock	$ 5,444,000
Remaining performance obligations				$ 14,241,000
Remaining performance obligation, expected timing of satisfaction, year				2020
VFMCRP Agreement [Member] \| License and Milestone Fees [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Total revenue				$ 8,021,000
License and milestone fees recognized				41,203,000
Maruishi and CKDP Agreements [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Receivables				$ 0
Other assets						0
Deferred revenue						$ 0
Number of remaining performance obligations \| item				0
Maruishi Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Number of performance obligations for revenue recognized \| item		2
Premium from sale of stock		$ 337,000
Upfront non-refundable, non-creditable license fee and premium from sale of stock		15,337,000
Maruishi Agreement [Member] \| Clinical Development and Regulatory Milestones [Member] \| Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Remaining potential consideration		10,500,000
Maruishi Agreement [Member] \| One-time Sales Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Remaining potential consideration \| ¥							¥ 1
Maruishi Agreement [Member] \| License [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Estimated selling price		10,200,000
Upfront payments on obligations		9,637,000
Maruishi Agreement [Member] \| R&D Services [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Estimated selling price		6,200,000
Upfront payments on obligations		$ 5,700,000
CKDP Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Premium from sale of stock			$ 83,000
CKDP Agreement [Member] \| Clinical Development and Regulatory Milestones [Member] \| Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Remaining potential consideration			3,750,000
CKDP Agreement [Member] \| License [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue from contract with customer			$ 646,000

Stock-Based Compensation - Additional Information (Detail) - USD ($)			1 Months Ended			3 Months Ended		12 Months Ended
	Jun. 04, 2020	Jun. 04, 2019	Feb. 29, 2020	Jun. 30, 2019	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2015	Jan. 01, 2020	Dec. 31, 2019	Nov. 20, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value						$ 0.001				$ 0.001
Compensation expense						$ 2,679,000	$ 2,234,000
Common stock, shares outstanding						46,727,725				46,720,225
Common stock, shares issued						46,727,725				46,720,225
Fair value of options granted						$ 10.59	$ 10.83
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 1,609,000	$ 1,082,000
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						1,070,000	1,152,000
Restricted Stock Units [Member] \| March 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						0	$ 0
Restricted stock units, vested							0
Restricted Stock Units [Member] \| Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						14,000
Restricted Stock Units [Member] \| General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						30,000
Director [Member] \| Restricted Stock Units [Member] \| General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 123,000
Director [Member] \| Share-based Payment Arrangement, Nonemployee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted						0	0
Director [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, vested						0
Executive Officers [Member] \| Share-based Payment Arrangement, Employee [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units						331,834
Consultants [Member] \| Share-based Payment Arrangement, Nonemployee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted						0	0
2019 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value											$ 0.001
Options granted						0
2019 Inducement Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized											300,000
2019 Inducement Plan [Member] \| Share-based Payment Arrangement, Employee [Member] \| Share-Based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vested shares on first anniversary of grant date						25.00%
2019 Inducement Plan [Member] \| Share-based Payment Arrangement, Employee [Member] \| Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						36 months
2019 Inducement Plan [Member] \| Share-based Payment Arrangement, Employee [Member] \| Share Based Compensation Subsequent Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						4 years
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options that may be granted after the tenth anniversary of the 2014 Plan						0
Annual increases in number of shares reserved for issuance as a percentage of shares of capital stock outstanding through January 1, 2024								3.00%
Share-based compensation arrangement by share-based payment award, number of shares authorized									7,488,513	6,086,907
Options granted						673,350	957,000
2014 Equity Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of awards granted						10 years
2014 Equity Incentive Plan [Member] \| Maximum [Member] \| Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized								30,000,000
2014 Equity Incentive Plan [Member] \| Director [Member] \| Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						3 years
2014 Equity Incentive Plan [Member] \| Director [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 123,000
2014 Equity Incentive Plan [Member] \| Director [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						1 year
Restricted stock units, approved and granted		24,000				24,000
Restricted stock units, grant date fair value	$ 20.47
Compensation expense						$ 123,000
2014 Equity Incentive Plan [Member] \| Director [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Minimum [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units vesting date	Jun. 04, 2020
2014 Equity Incentive Plan [Member] \| Executive Officers [Member] \| Restricted Stock Units [Member] \| February 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, approved and granted			138,000
Restricted stock units, grant date fair value			$ 16.36
Compensation expense						$ 0
2014 Equity Incentive Plan [Member] \| Executive Officers [Member] \| Restricted Stock Units [Member] \| March 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, approved and granted					215,000
Restricted stock units, grant date fair value					$ 16.10
Unvested restricted stock units						95,834
2014 Equity Incentive Plan [Member] \| Executive Officers [Member] \| Time-based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted			3 years
Restricted stock units, approved and granted			98,000
Restricted stock units, grant date fair value			$ 16.36
Compensation expense						$ 44,000
Restricted stock units, vested						0
2014 Equity Incentive Plan [Member] \| Executive Officers [Member] \| Time-based Restricted Stock Units [Member] \| Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 14,000
2014 Equity Incentive Plan [Member] \| Executive Officers [Member] \| Time-based Restricted Stock Units [Member] \| General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense						$ 30,000
2014 Equity Incentive Plan [Member] \| Employee And Nonemployee Consultants [Member] \| Share-Based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vested shares on first anniversary of grant date						25.00%
2014 Equity Incentive Plan [Member] \| Employee And Nonemployee Consultants [Member] \| Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						36 months
2014 Equity Incentive Plan [Member] \| Employee And Nonemployee Consultants [Member] \| Share Based Compensation Subsequent Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards granted						4 years
Non-employee Director Compensation Policy [Member] \| Director [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, approved and granted				6,000

Stock-Based Compensation - Summary of Assumptions Used in Black-Scholes Option Pricing Model (Detail)		3 Months Ended
	Jan. 01, 2019	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum		0.54%	2.54%
Risk-free interest rate, maximum		1.57%	2.62%
Expected volatility, minimum		73.72%	74.29%
Expected volatility, maximum		74.71%	75.19%
Expected dividend yield		0.00%	0.00%
Share-based Payment Arrangement, Nonemployee [Member] \| Consultants [Member] \| Re-Measurement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	2.59%
Risk-free interest rate, maximum	2.62%
Expected volatility, minimum	58.90%
Expected volatility, maximum	84.60%
Expected dividend yield	0.00%
Employee Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)		6 years 3 months	6 years 3 months
Employee Options [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Consultants [Member] \| Re-Measurement [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)	9 months 21 days
Employee Options [Member] \| Share-based Payment Arrangement, Nonemployee [Member] \| Consultants [Member] \| Re-Measurement [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of options (in years)	8 years 2 months 8 days

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefits from stock option activity or stock-based compensation expense recognized in cash flows from operations	$ 0	$ 0
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding	4,450,517
Number of Options, Granted	673,350	957,000
Number of Options, Exercised	(7,500)
Number of Options, Expired	(161,089)
Number of Options, Forfeited	(24,688)
Number of Options, Outstanding	4,930,590
Number of Options, Outstanding, Weighted average remaining contractual life as of March 31, 2020	7 years 8 months 4 days
Number of Options, Options exercisable	2,484,710
Number of Options, Exercisable, Weighted average remaining contractual life as of March 31, 2020	6 years 5 months 19 days
Number of Options, Options vested and expected to vest at December 31, 2019	4,930,590
Number of Options, Vested and expected to vest, Weighted average remaining contractual life as of March 31, 2020	7 years 8 months 4 days
Weighted-Average Exercise Price, Outstanding	$ 14.73
Weighted-Average Exercise Price, Granted	16.11
Weighted-Average Exercise Price, Exercised	9.94
Weighted-Average Exercise Price, Expired	13.64
Weighted-Average Exercise Price, Forfeited	16.51
Weighted-Average Exercise Price, Outstanding	14.95
Weighted-Average Exercise Price, Options exercisable, March 31, 2020	13.10
Weighted-Average Exercise Price, Options vested and expected to vest at March 31, 2020	$ 14.95
Aggregate Intrinsic Value, Outstanding at March 31, 2020	$ 5,099,000
Aggregate Intrinsic Value, Options exercisable at March 31, 2020	4,763,000
Aggregate Intrinsic Value, Options vested and expected to vest at March 31, 2020	$ 5,099,000
2019 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Granted	0

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended
	Aug. 20, 2019	Jul. 08, 2019	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2019	May 31, 2016
Other Commitments [Line Items]
Research and development			$ 33,536	$ 23,608
Operating lease liability			$ 4,087
Stamford Operating Lease [Member]
Other Commitments [Line Items]
Operating Lease, renewable term			5 years
Operating lease, expiration date			Nov. 30, 2023
Tenant improvement expenses						$ 1,094
Deferred lease obligation					$ 864
Operating lease cost			$ 234	234
Stamford Operating Lease [Member] \| Research and Development [Member]
Other Commitments [Line Items]
Operating lease cost			164	164
Stamford Operating Lease [Member] \| General and Administrative [Member]
Other Commitments [Line Items]
Operating lease cost			$ 70	$ 70
Stamford Operating Lease [Member] \| ASC 842 [Member]
Other Commitments [Line Items]
Operating lease liability					5,198
Stamford Operating Lease [Member] \| Standby Letter of Credit [Member]
Other Commitments [Line Items]
Letter of credit, renewal term			automatically renewed annually through November 2023.
Stamford Operating Lease [Member] \| Leasehold Improvements [Member]
Other Commitments [Line Items]
Tenant improvement expenses					$ 698
Non-Exclusive License Agreement
Other Commitments [Line Items]
Upfront fee	$ 8,000
Upfront fee payable, cash	4,000
Upfront fee payable, stock	$ 4,000
Percentage of payment, stock	50.00%
Payment of milestone payment			$ 0
Payments for Royalties			$ 0
License agreement expiration period, first commercial sale			10 years
Agreement Termination Notice Description			Either party may terminate the Enteris License Agreement upon written notice if the other party has failed to remedy a material breach within 60 days (or 30 days in the case of a material breach of a payment obligation). Enteris may terminate the Enteris License Agreement upon 30 days’ written notice to the Company if the Company or any of its affiliates formally challenge the validity of any licensed patent rights or assists a third party in doing so. The Company may terminate the Enteris License Agreement for any reason or no reason (a) prior to receipt of first regulatory approval for a licensed product in the United States for any indication upon 30 days’ prior written notice to Enteris or (b) on or after receipt of first regulatory approval for a licensed product in the United States for any indication upon 60 days’ prior written notice to Enteris.
MSA
Other Commitments [Line Items]
Agreement initial term, expiration date		Dec. 31, 2023
Agreement renewal term		2 years
MSA \| Minimum [Member]
Other Commitments [Line Items]
Termination notice effective period		18 months
MSA or Product Agreement
Other Commitments [Line Items]
Agreement Termination Notice Description			Either party may terminate the MSA or a Product Agreement upon written notice if the other party (1) has failed to remedy a material breach within a specified time or (2) is declared insolvent or bankrupt, voluntarily files a petition of bankruptcy or assigns such agreement for the benefit of creditors. The Company may terminate a Product Agreement (a) upon 90 days’ prior written notice if any governmental agency takes any action that prevents the Company from selling the relevant product in the relevant territory, (b) upon six months’ prior written notice if it does not intend to order manufacturing services due to a product’s discontinuance in the market, or (c) upon 90 days’ prior written notice if it determines that the manufacture or supply of a product likely infringes third-party rights. Patheon may terminate the MSA or a Product Agreement (i) upon six months’ prior written notice if the Company assigns such agreement to an assignee that is unacceptable to Patheon for certain reasons, or (ii) upon 30 days’ prior written notice if, after the first year of commercial sales, the Company forecasts zero volume for 12 months.

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Purchases of financial assets	$ 0	$ 0
Sales of financial assets	0	0
Maturities of financial assets	0	0
Transfer of financial asset into level 3 of fair value	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized gains	0	0
Unrealized losses	$ 0	$ 0

Restricted Cash - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash balance	$ 408	$ 408
Stamford Lease [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash balance	$ 408	$ 408

Prepaid Expenses - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid expenses	$ 10,688	$ 8,863
Prepaid R&D clinical costs	8,707	8,498
Prepaid insurance	1,705	181
Other prepaid costs	$ 276	$ 184

Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accounts payable	$ 9,309	$ 9,100
Accrued research projects	5,699	6,637
Accrued professional fees	736	635
Accrued compensation and benefits	1,627	3,293
Total	$ 17,371	$ 19,665

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Mar. 20, 2019	Mar. 31, 2020	Mar. 31, 2019
Subsidiary Sale Of Stock [Line Items]
Unregistered common stock exchanged for consulting services			$ 197
Compensation expense		$ 2,679	2,234
Shareholder Consulting Agreement [Member]
Subsidiary Sale Of Stock [Line Items]
Number of shares of unregistered common stock exchanged for consulting services	10,195
Price per share	$ 19.37
Consulting services performance period	6 months
Prepaid consulting services			197
Compensation expense			0
Additional Paid-In Capital [Member]
Subsidiary Sale Of Stock [Line Items]
Unregistered common stock exchanged for consulting services			197
Additional Paid-In Capital [Member] \| Shareholder Consulting Agreement [Member]
Subsidiary Sale Of Stock [Line Items]
Unregistered common stock exchanged for consulting services			$ 197

Condensed Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	46,727,725	46,720,225
Common stock, shares outstanding	46,727,725	46,720,225

Condensed Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Other comprehensive income, tax	$ 0	$ 0

Available-for-Sale Marketable Securities - Summary of Available-for-Sale Marketable Securities by Major Type of Security (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 162,796	$ 199,690
Gross Unrealized Gains	393	197
Gross Unrealized Losses	(461)	(27)
Estimated Fair Value	162,728	199,860
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	16,065	16,052
Gross Unrealized Gains	249	31
Gross Unrealized Losses		(2)
Estimated Fair Value	16,314	16,081
U.S. Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,601	25,803
Gross Unrealized Gains	39	14
Gross Unrealized Losses	(1)	(1)
Estimated Fair Value	17,639	25,816
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	93,681	115,788
Gross Unrealized Gains	79	125
Gross Unrealized Losses	(460)	(23)
Estimated Fair Value	93,300	115,890
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	31,949	38,547
Gross Unrealized Gains	26	27
Gross Unrealized Losses		(1)
Estimated Fair Value	31,975	38,573
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,500	3,500
Estimated Fair Value	$ 3,500	$ 3,500

Available-for-Sale Marketable Securities - Additional Information (Detail) $ in Thousands	Mar. 31, 2020 USD ($) position	Dec. 31, 2019 USD ($) position
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale allowance for credit loss \| $	$ 0	$ 0
Number of available-for-sale marketable securities in unrealized loss positions	29	16
Total number of positions	68	81
Available-for-sale marketable securities, continuous unrealized loss position, 12 Months or Greater, Gross Unrealized Losses \| $	$ 0	$ 0
U.S. Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale marketable securities in unrealized loss positions	1
Total number of positions	6
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of available-for-sale marketable securities in unrealized loss positions	28
Total number of positions	42

Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax, from Unrealized Gains (Losses) on Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Value	$ 186,713	$ 133,630
Other comprehensive income (loss) before reclassifications	(238)	187
Amount reclassified from accumulated other comprehensive income	0	0
Net current period other comprehensive income (loss)	(238)	187
Balance, Value	160,474	114,522
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance, Value	170	(114)
Net current period other comprehensive income (loss)	(238)	187
Balance, Value	$ (68)	$ 73

Restricted Cash - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 17,036	$ 18,305
Restricted cash balance	408	408
Total cash, cash equivalents, and restricted cash shown in the Condensed Statements of Cash Flows	$ 17,444	$ 18,713	$ 14,957	$ 15,850

Income Taxes - Additional Information (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($) subsidiary	Mar. 31, 2019 USD ($)	Dec. 31, 2019 subsidiary
Income Tax Disclosure [Abstract]
Pre-tax losses	$ 29,044	$ 22,045
Benefit from income taxes	$ 122	$ 85
Percentage of annual research and development credit for cash	65.00%	65.00%
Number of foreign subsidiaries \| subsidiary	0		0

Commitments and Contingencies - Schedule of Future Minimum Lease Payments under Non-cancellable Operating Leases, Reconciliation of Undiscounted Cash Flows to the Operating Lease Liability (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating Lease Liabilities, Payments Due [Abstract]
2020 (Excluding the three months ended March 31, 2020)	$ 933
2021	1,264
2022	1,288
2023	1,164
Total future minimum lease payments, undiscounted	4,649
Less imputed interest	(562)
Operating lease liability	4,087
Operating lease liability reported as of December 31, 2019:
Operating lease liability - current	991	$ 967
Operating lease liability - non-current	3,096	$ 3,352
Total	$ 4,087