View Filing Data

Document and Entity Information - shares	6 Months Ended
Jun. 30, 2018	Aug. 24, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Trading Symbol	CRNX
Entity Registrant Name	Crinetics Pharmaceuticals, Inc.
Entity Central Index Key	0001658247
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		24,024,231

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 68,408	$ 14,192
Prepaid expenses and other current assets	1,536	973
Total current assets	69,944	15,165
Property and equipment, net	1,808	400
Restricted cash	500
Other long-term assets	2,451	33
Total assets	74,703	15,598
Current liabilities:
Accounts payable	2,603	403
Accrued expenses	3,035	494
Total current liabilities	5,638	897
Deferred rent	1,050	20
Unvested stock liability	217	3
Total liabilities	6,905	920
Commitments and contingencies
Convertible preferred stock, $0.001 par; 48,868,345 shares authorized, 48,404,379 shares issued and outstanding, liquidation preference of $93,500 at June 30, 2018; 38,350,914 shares authorized, 28,763,179 shares issued and outstanding, liquidation preference of $30,000 at December 31, 2017	92,975	29,700
Stockholders’ equity (deficit):
Common stock, $0.001 par; 65,000,000 shares authorized, 2,483,386 shares issued and 2,344,362 shares outstanding at June 30, 2018; 50,500,000 shares authorized, 2,076,171 shares issued and 1,549,575 shares outstanding at December 31, 2017	2	1
Additional paid-in capital	2,118	1,242
Accumulated deficit	(27,297)	(16,265)
Total stockholders’ equity (deficit)	(25,177)	(15,022)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 74,703	$ 15,598

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	65,000,000	50,500,000
Common stock, shares issued	2,483,386	2,076,171
Common stock, shares outstanding	2,344,362	1,549,575
Convertible Preferred Stock
Temporary equity, par value	$ 0.001	$ 0.001
Temporary equity, shares authorized	48,868,345	38,350,914
Temporary equity, shares issued	48,404,379	28,763,179
Temporary equity, shares outstanding	48,404,379	28,763,179
Temporary equity, liquidation preference	$ 93,500	$ 30,000

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Grant revenues	$ 657	$ 832	$ 1,099	$ 877
Type of revenue [Extensible list]	us-gaap:GrantMember	us-gaap:GrantMember	us-gaap:GrantMember	us-gaap:GrantMember
Operating expenses:
Research and development	$ 5,222	$ 2,083	$ 9,942	$ 4,148
General and administrative	1,118	392	2,366	981
Total operating expenses	6,340	2,475	12,308	5,129
Loss from operations	(5,683)	(1,643)	(11,209)	(4,252)
Other income (expense):
Interest income	151	7	215	14
Interest expense		(3)		(5)
Other income (expense)	(36)	(9)	(38)	(11)
Total other income/ (expense), net	115	(5)	177	(2)
Net loss	$ (5,568)	$ (1,648)	$ (11,032)	$ (4,254)
Net loss per share:
Net loss per share – basic and diluted	$ (2.41)	$ (1.22)	$ (5.28)	$ (3.34)
Weighted-average shares outstanding – basic and diluted	2,307	1,348	2,089	1,273

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (11,032)	$ (4,254)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	698	128
Depreciation and amortization	124	52
Increase (decrease) in cash resulting from changes in:
Prepaid expenses and other assets	(1,275)	(475)
Accounts payable and accrued expenses	3,652	14
Deferred rent	76	10
Net cash used in operating activities	(7,757)	(4,525)
Cash flows from investing activities:
Purchases of property and equipment	(526)	(55)
Net cash used in investing activities	(526)	(55)
Financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	63,266	4,722
Proceeds from exercise of common stock options	393	63
Repayment of borrowings under long-term debt		(23)
Payment of initial public offering costs	(660)
Net cash provided by financing activities	62,999	4,762
Net change in cash, cash equivalents and restricted cash	54,716	182
Cash, cash equivalents and restricted cash at beginning of period	14,192	12,152
Cash, cash equivalents and restricted cash at end of period	68,908	12,334
Supplemental disclosures of cash flow information:
Cash paid for interest		$ 5
Noncash investing and financing activities:
Change in unvested stock liability	(7)
Accrued but unpaid preferred stock and initial public offering costs	1,046
Accrued but unpaid property and equipment purchases	52
Tenant improvement allowance	$ 954

Organization and Basis of Presentation	6 Months Ended
Organization and Basis of Presentation	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. ORGANIZATION AND BASIS OF PRESENTATION Description of Business Crinetics Pharmaceuticals, Inc. (the “Company”) is a clinical stage pharmaceutical company incorporated in Delaware on November 18, 2008 and based in San Diego, California. The Company is focused on the discovery, development and commercialization of novel therapeutics for rare endocrine diseases and endocrine-related tumors. In January 2017, the Company established a wholly-owned Australian subsidiary, Crinetics Australia Pty Ltd (“CAPL”), in order to conduct various preclinical and clinical activities for its development candidates. Reverse Stock Split On July 6, 2018, the Company effected a 1-for-3.29 reverse stock split of its common stock. The par value and the authorized shares of the common stock were not adjusted as a result of the reverse stock split. The reverse stock split resulted in an adjustment to the conversion prices of the Company’s Series A and B preferred stock to reflect a proportional decrease in the number of shares of common stock to be issued upon conversion. The accompanying condensed consolidated financial statements and notes to the condensed consolidated financial statements give retroactive effect to the reverse stock split for all periods presented. Segment Reporting Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment. Principles of Consolidation and Foreign Currency Transactions The condensed consolidated financial statements include the accounts of the Company and CAPL. All intercompany accounts and transactions have been eliminated in consolidation. The functional currency of both the Company and CAPL is the U.S. dollar. The Company’s assets and liabilities that are not denominated in the functional currency are remeasured into U.S. dollars at foreign currency exchange rates in effect at the balance sheet date except for nonmonetary assets, which are remeasured at historical foreign currency exchange rates in effect at the date of transaction. Net realized and unrealized gains and losses from foreign currency transactions and remeasurement are reported in other income (expense), in the condensed consolidated statements of operations and were not material for all periods presented. Unaudited Interim Financial Information The accompanying interim condensed consolidated balance sheet as of June 30, 2018, the condensed consolidated statements of operations for the three and six months ended June 30, 2018 and 2017, and the statements of cash flows for the six months ended June 30, 2018 and 2017, and the related disclosures are unaudited. In management’s opinion, the unaudited interim financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2018 and the results of its operations and cash flows for the three and six months ended June 30, 2018 and 2017 in accordance with U.S. GAAP. The results for the three and six months ended June 30, 2018 are not necessarily indicative of the results expected for the full fiscal year or any other interim period. Liquidity and Going Concern From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. As of June 30, 2018, the Company had $68.4 million in unrestricted cash and cash equivalents. Additionally, in July 2018, the Company issued 6,900,000 shares of its common stock in its initial public offering (the “IPO”) which provided net proceeds of $106.4 million. The Company believes it has sufficient cash to meet its funding requirements for at least the next 12 months. However, the Company has experienced net losses and negative cash flows from operating activities since its inception and has an accumulated deficit of $27.3 million as of June 30, 2018. The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of equity offerings, debt financings or other sources, including potentially collaborations, licenses and other similar arrangements. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future.

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The Company’s condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of the Company’s condensed consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes. The most significant estimates in the Company’s condensed consolidated financial statements relate to revenue recognition, accrued amounts receivable under the Australian research and development tax incentive program, accrued expenses, and the fair value of stock-based compensation. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying amounts of the Company’s current financial assets, restricted cash and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. As of each of June 30, 2018, and December 31, 2017, the Company had no financial assets measured at fair value on a recurring basis and none of the Company’s non-financial assets and liabilities were recorded at fair value on a non-recurring basis. No transfers between levels have occurred for the periods presented. Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts and a money market account. Restricted cash represents cash held as collateral for the Company’s facility lease and is reported as a long-term asset in the accompanying condensed consolidated balance sheets. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company has established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. Revenue Recognition The Company’s revenues are derived from Small Business Innovation Research (“SBIR”) grants from the National Institutes of Health. The Company recognizes SBIR grant revenue as reimbursable grant costs are incurred. The costs associated with these reimbursements are reflected as a component of research and development expense in the accompanying condensed consolidated statements of operations. Australian Research and Development Tax Incentive CAPL is eligible to obtain a cash refund from the Australian Taxation Office for eligible research and development expenditures under the Australian Research and Development Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to research and development expense when there is reasonable assurance that the Australian Tax Incentive will be received, the relevant expenditure has been incurred, and the amount can be reliably measured. The Company recognized reductions to research and development expense of $0.6 million and $0.9 million, respectively, for the three and six months ended June 30, 2018. The Company recognized a reduction to research and development expense of $23,000 for the three and six months ended June 30, 2017. Research and Development Expenses The Company’s research and development expenses consist primarily of salaries, payroll taxes, employee benefits and stock-based compensation charges for those individuals involved in research and development efforts, as well as consulting expenses, third-party research and development expenses, laboratory supplies, clinical materials and overhead, including facilities and depreciation costs, offset by the Australian Tax Incentive discussed above. Research and development expenses are charged to expense as incurred. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received. Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee awards over the requisite service period of the awards (usually the vesting period) on a straight-line basis. For stock awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable, or the performance condition has been achieved. The Company accounts for awards to nonemployees using the fair value method. Awards to nonemployees are subject to periodic revaluation over their vesting terms. The Company estimates the fair value of all stock option grants using the Black-Scholes option pricing model and recognizes forfeitures as they occur. Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of convertible preferred stock, common stock subject to repurchase, and options outstanding under the Company’s stock option plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which converges the FASB and the International Accounting Standards Board standard on revenue recognition. Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2017. The Company adopted ASU 2014-09 on January 1, 2018. The Company does not currently have any contracts with customers and, as such, the adoption had no material impact on its financial position and results of operations. In February 2016, the FASB issued ASU 2016-02, Leases, which outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new accounting standard requires lessees to recognize lease liabilities and corresponding right-of-use assets for all leases with lease terms of greater than twelve months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. The new accounting standard must be adopted using the modified retrospective approach and is effective for public entities for annual reporting periods beginning after December 15, 2018 with early adoption permitted. Although the Company is in the early stages of evaluating the impact of adoption of the ASU on its financial statements, the Company currently believes the most significant changes will be related to the recognition of lease liabilities on the Company’s consolidated balance sheets for real estate operating leases. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash, which requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities will no longer present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. The adoption of this standard, in the first quarter of 2018, changed the presentation of the Company’s statement of cash flows to include its restricted cash balance with non-restricted cash balances. The new guidance did not have a material impact on the Company’s condensed consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, which supersedes most of the prior accounting guidance on nonemployee share-based payments, and instead aligns it with existing guidance on employee share-based payments in Topic 718. As a result, nonemployee share-based payment transactions will be measured by estimating the fair value of the equity instruments that an entity is obligated to issue, and the measurement date will be consistent with the measurement date for employee share-based payment awards. Probability is to be considered on nonemployee awards with performance conditions. The classification will continue to be subject to the requirements of Topic 718, although cost recognition of nonemployee awards will remain unchanged. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2018 with early adoption permitted, but no earlier than an entity’s adoption date of Topic 606. The Company is in the process of determining the effects the adoption will have on its consolidated financial statements.

Balance Sheet Details

6 Months Ended

Jun. 30, 2018

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Balance Sheet Details

3. BALANCE SHEET DETAILS

Prepaid expenses and other current assets consist of the following (in thousands):

	June 30, 2018		December 31, 2017
SBIR grant receivable	$	657	$	231
Australian tax incentive receivable		566		503
Other		313		239
Total	$	1,536	$	973

Property and equipment consisted of the following (in thousands):

	June 30, 2018			December 31, 2017
Leasehold improvements	$	972		$	18
Laboratory equipment		662			640
Office equipment		257			19
Computers and software		36			27
Construction in progress		309			—
Property and equipment at cost		2,236			704
Accumulated depreciation and amortization		(428	)		(304	)
Total	$	1,808		$	400

Other long-term assets consist of the following (in thousands):

	June 30, 2018		December 31, 2017
Deferred initial public offering costs	$	1,706	$	—
Long-term portion of Australian tax incentive receivable		734		—
Other		11		33
Total	$	2,451	$	33

Accrued expenses consist of the following (in thousands):

	June 30, 2018		December 31, 2017
Accrued research and development costs	$	1,358	$	126
Accrued compensation		1,006		315
Other accrued expenses		671		53
Total	$	3,035	$	494

Convertible Preferred Stock

6 Months Ended

Jun. 30, 2018

Temporary Equity Disclosure [Abstract]

Convertible Preferred Stock

5. CONVERTIBLE PREFERRED STOCK

The authorized, issued and outstanding shares of convertible preferred stock as of June 30, 2018 consisted of the following (in thousands, except share amounts):

			Shares
	Shares		Issued and		Liquidation		Carrying
	Authorized		Outstanding		Preference		Value
Series A		28,763,179		28,763,179	$	30,000	$	29,700
Series B		20,105,166		19,641,200		63,500		63,275
Total		48,868,345		48,404,379	$	93,500	$	92,975

The authorized, issued and outstanding shares of convertible preferred stock as of December 31, 2017 consisted of the following (in thousands, except share amounts):

Issued and

Liquidation

Carrying

Authorized

Outstanding

Preference

Value

Series A

38,350,914

28,763,179

30,000

29,700

Convertible Preferred Stock Transactions

In February and March 2018, pursuant to a Series B stock purchase agreement entered into in February 2018 which called for an initial closing and a subsequent closing, the Company issued an aggregate of 19,641,200 shares of its Series B convertible preferred stock at a purchase price of $3.233 per share, for aggregate gross proceeds of $63.5 million. The Company incurred $0.2 million of issuance costs in connection with the Series B financing (see Note 9).

Equity Incentive Plan

6 Months Ended

Jun. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity Incentive Plan

7. EQUITY INCENTIVE PLAN

In February 2015, the Company adopted the Crinetics Pharmaceuticals, Inc. 2015 Stock Incentive Plan (the “Plan”), which provides for the issuance of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit awards and other stock awards to its employees, members of its board of directors and consultants. The Plan expires in February 2025 and, in general, the options issued under the Plan expire ten years from the date of grant and vest over a four-year period. In May 2018, the shares reserved for issuance under the 2015 Stock Incentive Plan were increased by 729,484 shares to a total of 3,142,857 shares. As of June 30, 2018, 391,637 shares remained available for future issuance under the Plan.

The Plan allows for early exercise of stock options, and early-exercised options and restricted stock awards may be subject to repurchase by the Company until they become fully vested. As of June 30, 2018, there were 139,025 shares issued and subject to repurchase as a result of the early exercise of stock options, resulting in an unvested stock liability of $0.2 million.

A summary of the Company’s 2018 option activity (and other related information) is as follows:

				Weighted-		Weighted-		Aggregate
				Average		Average		Intrinsic
	Options			Exercise		Remaining		Value
	Outstanding			Price		Term		(000’s)
Balance at December 31, 2017		838,276		$	0.80
Granted		1,866,094		$	6.22
Exercised		(407,218	)	$	0.97
Forfeited and expired		(22,164	)	$	0.91
Balance at June 30, 2018		2,274,988		$	5.21		9.4	$	15,227
Exercisable at June 30, 2018		379,534		$	1.25		8.7	$	4,082

Fair Value of Equity Awards

The Company utilized the Black-Scholes option pricing model to value its equity awards granted to employees during the first six months of each of 2018 and 2017 using the following weighted-average assumptions:

	2018	2017
Expected life of option	6.0 years	6.1 years
Volatility	70%	66%
Risk free interest rate	2.8%	1.9%
Dividend yield	—%	—%

The weighted-average fair value of options granted to employees during the first six months of each of 2018 and 2017 was $4.02 and $0.44 per share, respectively.

Stock-Based Compensation Expense

The assumptions used in the Black-Scholes option pricing model to determine the fair value of employee stock option grants were as follows:

•

Risk-free interest rate. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for zero coupon U.S. Treasury notes with maturities equal to the expected term of the awards.

•

Expected volatility. Since the Company does not have a significant trading history for its common stock, the expected volatility assumption is based on volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available

•

Expected term. The expected term represents the period that options are expected to be outstanding. Because the Company does not have historical exercise behavior, it determines the expected life assumption using the simplified method, for employees, which is an average of the contractual term of the option and its vesting period.

•

Expected dividend yield. The Company bases the expected dividend yield assumption on the fact that it has never paid cash dividends and has no present intention to pay cash dividends, therefore, the Company used an expected dividend yield of zero.

Stock-based compensation expense recognized for all equity awards has been reported in the condensed consolidated statements of operations as follows (in thousands):

	Three months ended				Six months ended
	June 30,				June 30,
	2018		2017		2018		2017
Included in research and development	$	130	$	34	$	291	$	60
Included in general and administrative		141		39		407		68
Total	$	271	$	73	$	698	$	128

As of June 30, 2018, unrecognized stock-based compensation costs related to employee awards was $7.1 million, which is expected to be recognized over a remaining weighted-average period of approximately 3.8 years.

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2018
Accounting Policies [Abstract]
Description of Business	Description of Business Crinetics Pharmaceuticals, Inc. (the “Company”) is a clinical stage pharmaceutical company incorporated in Delaware on November 18, 2008 and based in San Diego, California. The Company is focused on the discovery, development and commercialization of novel therapeutics for rare endocrine diseases and endocrine-related tumors. In January 2017, the Company established a wholly-owned Australian subsidiary, Crinetics Australia Pty Ltd (“CAPL”), in order to conduct various preclinical and clinical activities for its development candidates.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment.
Principles of Consolidation and Foreign Currency Transactions	Principles of Consolidation and Foreign Currency Transactions The condensed consolidated financial statements include the accounts of the Company and CAPL. All intercompany accounts and transactions have been eliminated in consolidation. The functional currency of both the Company and CAPL is the U.S. dollar. The Company’s assets and liabilities that are not denominated in the functional currency are remeasured into U.S. dollars at foreign currency exchange rates in effect at the balance sheet date except for nonmonetary assets, which are remeasured at historical foreign currency exchange rates in effect at the date of transaction. Net realized and unrealized gains and losses from foreign currency transactions and remeasurement are reported in other income (expense), in the condensed consolidated statements of operations and were not material for all periods presented.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying interim condensed consolidated balance sheet as of June 30, 2018, the condensed consolidated statements of operations for the three and six months ended June 30, 2018 and 2017, and the statements of cash flows for the six months ended June 30, 2018 and 2017, and the related disclosures are unaudited. In management’s opinion, the unaudited interim financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2018 and the results of its operations and cash flows for the three and six months ended June 30, 2018 and 2017 in accordance with U.S. GAAP. The results for the three and six months ended June 30, 2018 are not necessarily indicative of the results expected for the full fiscal year or any other interim period.
Liquidity and Going Concern	Liquidity and Going Concern From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. As of June 30, 2018, the Company had $68.4 million in unrestricted cash and cash equivalents. Additionally, in July 2018, the Company issued 6,900,000 shares of its common stock in its initial public offering (the “IPO”) which provided net proceeds of $106.4 million. The Company believes it has sufficient cash to meet its funding requirements for at least the next 12 months. However, the Company has experienced net losses and negative cash flows from operating activities since its inception and has an accumulated deficit of $27.3 million as of June 30, 2018. The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of equity offerings, debt financings or other sources, including potentially collaborations, licenses and other similar arrangements. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future.
Use of Estimates	Use of Estimates The Company’s condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of the Company’s condensed consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed consolidated financial statements and accompanying notes. The most significant estimates in the Company’s condensed consolidated financial statements relate to revenue recognition, accrued amounts receivable under the Australian research and development tax incentive program, accrued expenses, and the fair value of stock-based compensation. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Fair Value Measurements	Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying amounts of the Company’s current financial assets, restricted cash and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. As of each of June 30, 2018, and December 31, 2017, the Company had no financial assets measured at fair value on a recurring basis and none of the Company’s non-financial assets and liabilities were recorded at fair value on a non-recurring basis. No transfers between levels have occurred for the periods presented.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with maturities of three months or less when purchased to be cash equivalents. Cash and cash equivalents include cash in readily available checking accounts and a money market account. Restricted cash represents cash held as collateral for the Company’s facility lease and is reported as a long-term asset in the accompanying condensed consolidated balance sheets.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company has established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity.
Revenue Recognition	Revenue Recognition The Company’s revenues are derived from Small Business Innovation Research (“SBIR”) grants from the National Institutes of Health. The Company recognizes SBIR grant revenue as reimbursable grant costs are incurred. The costs associated with these reimbursements are reflected as a component of research and development expense in the accompanying condensed consolidated statements of operations.
Australian Research and Development Tax Incentive	Australian Research and Development Tax Incentive CAPL is eligible to obtain a cash refund from the Australian Taxation Office for eligible research and development expenditures under the Australian Research and Development Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to research and development expense when there is reasonable assurance that the Australian Tax Incentive will be received, the relevant expenditure has been incurred, and the amount can be reliably measured. The Company recognized reductions to research and development expense of $0.6 million and $0.9 million, respectively, for the three and six months ended June 30, 2018. The Company recognized a reduction to research and development expense of $23,000 for the three and six months ended June 30, 2017.
Research and Development Expenses	Research and Development Expenses The Company’s research and development expenses consist primarily of salaries, payroll taxes, employee benefits and stock-based compensation charges for those individuals involved in research and development efforts, as well as consulting expenses, third-party research and development expenses, laboratory supplies, clinical materials and overhead, including facilities and depreciation costs, offset by the Australian Tax Incentive discussed above. Research and development expenses are charged to expense as incurred. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee awards over the requisite service period of the awards (usually the vesting period) on a straight-line basis. For stock awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable, or the performance condition has been achieved. The Company accounts for awards to nonemployees using the fair value method. Awards to nonemployees are subject to periodic revaluation over their vesting terms. The Company estimates the fair value of all stock option grants using the Black-Scholes option pricing model and recognizes forfeitures as they occur.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. There have been no items qualifying as other comprehensive loss and, therefore, for all periods presented, the Company’s comprehensive loss was the same as its reported net loss.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of convertible preferred stock, common stock subject to repurchase, and options outstanding under the Company’s stock option plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which converges the FASB and the International Accounting Standards Board standard on revenue recognition. Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2017. The Company adopted ASU 2014-09 on January 1, 2018. The Company does not currently have any contracts with customers and, as such, the adoption had no material impact on its financial position and results of operations. In February 2016, the FASB issued ASU 2016-02, Leases, which outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new accounting standard requires lessees to recognize lease liabilities and corresponding right-of-use assets for all leases with lease terms of greater than twelve months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. The new accounting standard must be adopted using the modified retrospective approach and is effective for public entities for annual reporting periods beginning after December 15, 2018 with early adoption permitted. Although the Company is in the early stages of evaluating the impact of adoption of the ASU on its financial statements, the Company currently believes the most significant changes will be related to the recognition of lease liabilities on the Company’s consolidated balance sheets for real estate operating leases. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash, which requires entities to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. As a result, entities will no longer present transfers between cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. The adoption of this standard, in the first quarter of 2018, changed the presentation of the Company’s statement of cash flows to include its restricted cash balance with non-restricted cash balances. The new guidance did not have a material impact on the Company’s condensed consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, which supersedes most of the prior accounting guidance on nonemployee share-based payments, and instead aligns it with existing guidance on employee share-based payments in Topic 718. As a result, nonemployee share-based payment transactions will be measured by estimating the fair value of the equity instruments that an entity is obligated to issue, and the measurement date will be consistent with the measurement date for employee share-based payment awards. Probability is to be considered on nonemployee awards with performance conditions. The classification will continue to be subject to the requirements of Topic 718, although cost recognition of nonemployee awards will remain unchanged. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2018 with early adoption permitted, but no earlier than an entity’s adoption date of Topic 606. The Company is in the process of determining the effects the adoption will have on its consolidated financial statements.

Balance Sheet Details (Tables)

6 Months Ended

Jun. 30, 2018

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Components of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):

	June 30, 2018		December 31, 2017
SBIR grant receivable	$	657	$	231
Australian tax incentive receivable		566		503
Other		313		239
Total	$	1,536	$	973

Components of Property and Equipment

Property and equipment consisted of the following (in thousands):

	June 30, 2018			December 31, 2017
Leasehold improvements	$	972		$	18
Laboratory equipment		662			640
Office equipment		257			19
Computers and software		36			27
Construction in progress		309			—
Property and equipment at cost		2,236			704
Accumulated depreciation and amortization		(428	)		(304	)
Total	$	1,808		$	400

Components of Other Long-Term Assets

Other long-term assets consist of the following (in thousands):

	June 30, 2018		December 31, 2017
Deferred initial public offering costs	$	1,706	$	—
Long-term portion of Australian tax incentive receivable		734		—
Other		11		33
Total	$	2,451	$	33

Components of Accrued Expenses

Accrued expenses consist of the following (in thousands):

	June 30, 2018		December 31, 2017
Accrued research and development costs	$	1,358	$	126
Accrued compensation		1,006		315
Other accrued expenses		671		53
Total	$	3,035	$	494

Convertible Preferred Stock (Tables)

6 Months Ended

Jun. 30, 2018

Temporary Equity Disclosure [Abstract]

Summary of Authorized, Issued and Outstanding Shares of Convertible Preferred Stock

The authorized, issued and outstanding shares of convertible preferred stock as of June 30, 2018 consisted of the following (in thousands, except share amounts):

			Shares
	Shares		Issued and		Liquidation		Carrying
	Authorized		Outstanding		Preference		Value
Series A		28,763,179		28,763,179	$	30,000	$	29,700
Series B		20,105,166		19,641,200		63,500		63,275
Total		48,868,345		48,404,379	$	93,500	$	92,975

The authorized, issued and outstanding shares of convertible preferred stock as of December 31, 2017 consisted of the following (in thousands, except share amounts):

Issued and

Liquidation

Carrying

Authorized

Outstanding

Preference

Value

Series A

38,350,914

28,763,179

30,000

29,700

Equity Incentive Plan (Tables)

6 Months Ended

Jun. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Option Activity

A summary of the Company’s 2018 option activity (and other related information) is as follows:

				Weighted-		Weighted-		Aggregate
				Average		Average		Intrinsic
	Options			Exercise		Remaining		Value
	Outstanding			Price		Term		(000’s)
Balance at December 31, 2017		838,276		$	0.80
Granted		1,866,094		$	6.22
Exercised		(407,218	)	$	0.97
Forfeited and expired		(22,164	)	$	0.91
Balance at June 30, 2018		2,274,988		$	5.21		9.4	$	15,227
Exercisable at June 30, 2018		379,534		$	1.25		8.7	$	4,082

Summary of Black Scholes Option Pricing Model to Value Equity Awards Granted

	2018	2017
Expected life of option	6.0 years	6.1 years
Volatility	70%	66%
Risk free interest rate	2.8%	1.9%
Dividend yield	—%	—%

Stock-based Compensation Expense Recognized for Equity Awards

Stock-based compensation expense recognized for all equity awards has been reported in the condensed consolidated statements of operations as follows (in thousands):

	Three months ended				Six months ended
	June 30,				June 30,
	2018		2017		2018		2017
Included in research and development	$	130	$	34	$	291	$	60
Included in general and administrative		141		39		407		68
Total	$	271	$	73	$	698	$	128

Organization and Basis of Presentation - Additional Information (Details) $ in Thousands				6 Months Ended
	Jul. 20, 2018 USD ($) shares	Jul. 17, 2018 USD ($) shares	Jul. 06, 2018	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Organization And Basis Of Presentation [Line Items]
Number of operating segments				1
Unrestricted cash and cash equivalents				$ 68,408	$ 14,192
Accumulated deficit				$ 27,300
Minimum
Organization And Basis Of Presentation [Line Items]
Period of sufficient cash to meet its funding requirements				12 months
Subsequent Event \| IPO
Organization And Basis Of Presentation [Line Items]
Net proceeds (including over-allotment)	$ 106,400	$ 106,400
Common Stock \| Subsequent Event
Organization And Basis Of Presentation [Line Items]
Stock reverse stock split			1-for-3.29
Stock split conversion ratio			0.3040
Common Stock \| Subsequent Event \| IPO
Organization And Basis Of Presentation [Line Items]
Shares issued during period, new issues \| shares	6,900,000	6,900,000

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Fair value assets transferred from level 1 to level 2	$ 0		$ 0		$ 0
Fair value assets transferred from level 2 to level 1	0		0		0
Fair value liabilities transferred from level 1 to level 2	0		0		0
Fair value liabilities transferred from level 2 to level 1	0		0		0
Fair value assets transferred into level 3			0		0
Fair value assets transferred out of level 3			0		0
Fair value liabilities transferred into level 3			0		0
Fair value liabilities transferred out of level 3			0		0
Australian Research and Development Tax Incentive \| Australian Taxation Office
Summary Of Significant Accounting Policies [Line Items]
Tax incentive receivable, reductions to research and development expense	600,000	$ 23,000	900,000	$ 23,000
Fair Value, Measurements, Recurring
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure	0		0		0
Fair Value, Measurements, Nonrecurring
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure	0		0		0
Liabilities, fair value disclosure	$ 0		$ 0		$ 0

Commitments and Contingencies - Schedule of Future Minimum Payments Under Non-cancellable Operating Leases (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Commitments And Contingencies Disclosure [Abstract]
2018 (6 months)	$ 286
2019	1,189
2020	1,170
2021	1,173
2022	1,208
Thereafter	3,395
Total	$ 8,421

Convertible Preferred Stock - Summary of Authorized, Issued and Outstanding Shares of Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Temporary Equity [Line Items]
Temporary equity, carrying value	$ 92,975		$ 29,700
Series A
Temporary Equity [Line Items]
Temporary equity, shares authorized	28,763,179		38,350,914
Temporary equity, shares issued	28,763,179		28,763,179
Temporary equity, shares outstanding	28,763,179		28,763,179
Temporary equity, liquidation preference	$ 30,000		$ 30,000
Temporary equity, carrying value	$ 29,700		$ 29,700
Series B
Temporary Equity [Line Items]
Temporary equity, shares authorized	20,105,166
Temporary equity, shares issued	19,641,200	19,641,200
Temporary equity, shares outstanding	19,641,200
Temporary equity, liquidation preference	$ 63,500
Temporary equity, carrying value	$ 63,275
Convertible Preferred Stock
Temporary Equity [Line Items]
Temporary equity, shares authorized	48,868,345		38,350,914
Temporary equity, shares issued	48,404,379		28,763,179
Temporary equity, shares outstanding	48,404,379		28,763,179
Temporary equity, liquidation preference	$ 93,500		$ 30,000

Equity Incentive Plan - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	6 Months Ended
	May 31, 2018	Jun. 30, 2018	Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued and subject to repurchase as result of exercise of stock options		139,025
Unvested stock liability		$ 0.2
Weighted-average fair value of options granted to employees per share		$ 4.02	$ 0.44
Dividend yield		0.00%
Unrecognized stock-based compensation costs		$ 7.1
Weighted-average period of unrecognized stock-based compensation costs expected to be recognized over remaining period		3 years 9 months 18 days
2015 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan expiration period		2025-02
Plan expiration term		10 years
Vesting period		4 years
Increased shares reserved for issuance	729,484
Shares reserved for issuance, authorized	3,142,857
Remaining shares available for future issuance		391,637

Equity Incentive Plan - Summary of Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Beginning balance \| shares	838,276
Options Outstanding, Granted \| shares	1,866,094
Options Outstanding, Exercised \| shares	(407,218)
Options Outstanding, Forfeited and expired \| shares	(22,164)
Options Outstanding, Ending balance \| shares	2,274,988
Options Outstanding, Exercisable \| shares	379,534
Weighted-Average Exercise Price, Beginning balance \| $ / shares	$ 0.80
Weighted-Average Exercise Price, Granted \| $ / shares	6.22
Weighted Average Exercise Price, Exercised \| $ / shares	0.97
Weighted Average Exercise Price, Forfeited and expired \| $ / shares	0.91
Weighted-Average Exercise Price, Ending balance \| $ / shares	5.21
Weighted-Average Exercise Price, Exercisable \| $ / shares	$ 1.25
Weighted-Average Remaining Term, Ending balance	9 years 4 months 24 days
Weighted-Average Remaining Term, Exercisable	8 years 8 months 12 days
Aggregate Intrinsic Value, Ending balance \| $	$ 15,227
Aggregate Intrinsic Value, Exercisable \| $	$ 4,082

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 31, 2018	Jul. 20, 2018	Jul. 17, 2018	Jun. 30, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Common stock, shares authorized				65,000,000	50,500,000
Subsequent Event \| 2018 Equity Incentive Plan
Subsequent Event [Line Items]
Shares reserved for issuance, authorized	1,600,000
Plan expiration term	10 years
Percentage increase in number of shares of common stock reserved for future issuance	5.00%
Subsequent Event \| 2018 Employee Stock Purchase Plan
Subsequent Event [Line Items]
Shares reserved for issuance, authorized	250,000
Plan expiration term	10 years
Percentage increase in number of shares of common stock reserved for future issuance	1.00%
Maximum percentage of base pay that a participating employee may elect	20.00%
Subsequent Event \| IPO
Subsequent Event [Line Items]
Proceeds from IPO net of underwriting discounts and commissions and offering costs		$ 106.4	$ 106.4
Common stock, shares authorized		200,000,000
Preferred stock, shares authorized		10,000,000
Subsequent Event \| Common Stock \| IPO
Subsequent Event [Line Items]
Share of common stock issued		6,900,000	6,900,000
Sale of stock, price per share		$ 17.00
Subsequent Event \| Convertible Preferred Stock \| IPO
Subsequent Event [Line Items]
Shares issued upon conversion		14,712,571

Stockholders Equity	6 Months Ended
Stockholders Equity	Jun. 30, 2018
Equity [Abstract]
Stockholders Equity	6. STOCKHOLDERS’ EQUITY Shares of Common Stock Subject to Repurchase In October 2015, in connection with the issuance of the Company’s Series A convertible preferred stock, certain of the Company’s founders entered into stock restriction agreements, whereby 1,914,893 of previously unrestricted shares of common stock became subject to repurchase by the Company upon the stockholder’s termination of employment or service to the Company. The Company’s repurchase rights lapsed as to 765,957 shares of common stock in October 2015, with the remainder scheduled to lapse at the rate of 23,936 shares monthly thereafter such that the shares of common stock would have been fully vested in October 2019. Under the terms of the stock restriction agreements, the shares of common stock were also subject to accelerated vesting upon certain events, such that all such restricted shares became fully vested upon the closing of the Company’s Series B preferred stock financing in February 2018 (see Note 5). The stock restriction agreements resulted in the deemed cancellation and reissuance of shares of common stock and therefore, for accounting purposes, the shares subject to repurchase were not considered to be outstanding until vested. The fair value of these shares of $1.4 million as of October 2015 was recognized as compensation expense over the vesting period. For the three and six months ended June 30, 2018, the Company recognized stock-based compensation for these awards of zero and $0.4 million, respectively. For the three and six months ended June 30, 2017, the Company recognized stock-based compensation for these awards of $51,000 and $0.1 million, respectively.

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	9. SUBSEQUENT EVENTS Initial Public Offering On July 20, 2018, the Company completed its initial public offering (“IPO”) whereby it sold 6,900,000 shares of common stock at a price to the public of $17.00 per share. Proceeds from the IPO were approximately $106.4 million, net of underwriting discounts and commissions and offering costs. In connection with the IPO, the outstanding shares of the Company’s convertible preferred stock automatically converted into 14,712,571 shares of common stock. In addition, an amended and restated certificate of incorporation was filed by the Company on July 20, 2018, authorizing 200,000,000 shares of common stock and 10,000,000 shares of undesignated preferred stock. Equity Plans Approval of the 2018 Equity Incentive Award Plan. In July 2018, the Company’s board of directors and stockholders approved and adopted the 2018 Incentive Award Plan (the “2018 Plan”). The 2018 Plan became effective on the day prior to the effectiveness of the IPO. Under the 2018 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock or cash-based awards to individuals who are then employees, officers, directors or consultants of the Company, and employees and consultants of the Company’s subsidiaries. A total of 1,600,000 shares of common stock were approved to be initially reserved for issuance under the 2018 Plan. The number of shares reserved that were remaining under the 2015 Plan as of the effective date of the 2018 Plan were added to the shares initially reserved under the 2018 Plan upon its effectiveness. In addition, the number of shares of common stock available for issuance under the 2018 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2018 Plan, beginning with January 1, 2019, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year or such lesser amount as determined by the Company’s board of directors. Approval of the 2018 Employee Stock Purchase Plan. In July 2018, the Company’s board of directors and stockholders approved and adopted the 2018 Employee Stock Purchase Plan (the “ESPP”). The ESPP became effective on the day prior to the effectiveness of the IPO. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation. A total of 250,000 shares of common stock were approved to be initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the ten-year term of the ESPP, beginning with January 1, 2019, by an amount equal to 1% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year or such lesser amount as determined by the Company’s board of directors.

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
2018 Operating Lease
Loss Contingencies [Line Items]
Operating lease, initial term		7 years
Operating lease, option to extend term	five years
Irrevocable letter of credit		$ 0.5
2013 Operating Lease
Loss Contingencies [Line Items]
Operating lease, option to extend term	two years
Operating lease expiration period	2020-04
Lessee leasing arrangements early termination of operating leases term of contract description	The Company has an early termination option subject to at least five months prior written notice and a termination fee of two months base rent and the unamortized portion of any leasing costs, abated rent and any other lease concessions.

Stockholders Equity - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2015	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expenses		$ 271,000	$ 73,000	$ 698,000	$ 128,000
Stock Restriction Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrestricted shares of common stock repurchased	1,914,893
Common stock repurchase rights lapsed	765,957
Common stock repurchase rights to be lapsed monthly thereafter till fully vested in October 2019				23,936
Unrestricted shares of common stock fair value	$ 1,400,000
Stock-based compensation expenses		$ 0	$ 51,000	$ 400,000	$ 100,000

Net Loss Per Share - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	17,126,584	8,024,221	17,126,584	8,024,221
Convertible Preferred Stock Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	14,712,571	6,629,808	14,712,571	6,629,808
Common Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	2,274,988	724,200	2,274,988	724,200
Unvested Common Stock Subject to Repurchase
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	139,025	670,213	139,025	670,213

Balance Sheet Details - Components of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
SBIR grant receivable	$ 657	$ 231
Australian tax incentive receivable	566	503
Other	313	239
Total	$ 1,536	$ 973

Balance Sheet Details - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment at cost	$ 2,236	$ 704
Accumulated depreciation and amortization	(428)	(304)
Total	1,808	400
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment at cost	972	18
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment at cost	662	640
Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment at cost	257	19
Computers and Software
Property Plant And Equipment [Line Items]
Property and equipment at cost	36	$ 27
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment at cost	$ 309

Balance Sheet Details - Components of Other Long-Term Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Assets Noncurrent [Abstract]
Deferred initial public offering costs	$ 1,706
Long-term portion of Australian tax incentive receivable	734
Other	11	$ 33
Total	$ 2,451	$ 33

Balance Sheet Details - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued research and development costs	$ 1,358	$ 126
Accrued compensation	1,006	315
Other accrued expenses	671	53
Total	$ 3,035	$ 494