Morphic Holding (MORF) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 11, 2019
Document and Entity Information
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Entity Registrant Name	MORPHIC HOLDING, INC.
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		30,483,521
Entity Central Index Key	0001679363
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 159,807	$ 185,901
Marketable securities	91,939	0
Accounts receivable	2,364
Prepaid expenses and other current assets	2,926	1,222
Total current assets	257,036	187,123
Property and equipment, net	2,716	1,843
Restricted cash	275	275
Other assets	52	64
Total assets	260,079	189,305
Current liabilities:
Accounts payable	3,285	1,745
Accrued expenses	5,051	3,239
Deferred revenue, current portion	18,063	29,862
Deferred rent, current portion	80	57
Total current liabilities	26,479	34,903
Long-term liabilities:
Deferred revenue, net of current portion	74,010	66,781
Deferred rent, net of current portion	242	306
Other long-term liabilities		58
Total liabilities	100,731	102,048
Commitments and contingencies (Note 9)
Stockholders’ Equity (Deficit)
Preferred shares, $0.0001 par value, 10,000,000 shares authorized, no shares issued and outstanding as of September 30, 2019 and December 31, 2018
Common shares, $0.0001 par value, 400,000,000 shares authorized, 30,034,268 shares issued and outstanding as of September 30, 2019 and 151,000,000 shares authorized and 1,832,923 shares issued and outstanding as of December 31, 2018	3
Additional paid-in capital	236,980	1,633
Accumulated deficit	(77,682)	(54,185)
Accumulated other comprehensive income	47
Total stockholders’ equity (deficit)	159,348	(52,552)
Total liabilities, preferred shares, and stockholders’ equity (deficit)	$ 260,079	189,305
Series Seed Preferred Shares
Long-term liabilities:
Preferred shares		8,658
Series A Preferred Shares
Long-term liabilities:
Preferred shares		51,320
Series B Preferred Shares
Long-term liabilities:
Preferred shares		$ 79,831

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Preferred shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred shares, shares authorized	10,000,000	10,000,000
Preferred shares, shares issued	0	0
Preferred shares, shares outstanding	0	0
Common shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized	400,000,000	151,000,000
Common shares, shares issued	30,034,268	1,832,923
Common shares, shares outstanding	30,034,268	1,832,923
Series Seed Convertible Preferred Shares
Preferred shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred shares, shares authorized	0	11,967,689
Preferred shares, shares Issued	0	2,045,556
Preferred shares, shares outstanding	0	2,045,556
Preferred shares, liquidation preference		$ 8,980
Series A Convertible Preferred Shares
Preferred shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred shares, shares authorized	0	49,047,619
Preferred shares, shares Issued	0	8,411,368
Preferred shares, shares outstanding	0	8,411,368
Preferred shares, liquidation preference		$ 51,500
Series B Convertible Preferred Shares
Preferred shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred shares, shares authorized	0	61,538,454
Preferred shares, shares Issued	0	10,553,483
Preferred shares, shares outstanding	0	10,553,483
Preferred shares, liquidation preference		$ 80,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Collaboration revenue	$ 5,675,000		$ 17,311,000
Operating expenses:
Research and development	12,635,000	$ 5,767,000	36,912,000	$ 15,344,000
General and administrative	2,898,000	1,405,000	6,807,000	3,311,000
Total operating expenses	15,533,000	7,172,000	43,719,000	18,655,000
Loss from operations	(9,858,000)	(7,172,000)	(26,408,000)	(18,655,000)
Other income:
Interest income, net	1,392,000	111,000	3,574,000	214,000
Other expense, net	(94,000)	(16,000)	(94,000)	(46,000)
Total other income, net	1,298,000	95,000	3,480,000	168,000
Loss before provision for income taxes	(8,560,000)	(7,077,000)	(22,928,000)	(18,487,000)
Provision for income taxes	(304,000)	0	(569,000)	0
Net loss	$ (8,864,000)	$ (7,077,000)	$ (23,497,000)	$ (18,487,000)
Net loss per unit, basic and diluted
Net loss per share, basic and diluted	$ (0.30)		$ (2.06)
Net loss per unit, basic and diluted		$ (7)		$ (18.28)
Weighted average common units outstanding, basic and diluted
Weighted average common shares outstanding, basic and diluted	29,999,170		11,393,192
Weighted average common units outstanding, basic and diluted		1,011,227		1,011,227
Other comprehensive income (loss):
Unrealized holding gains on marketable securities, net of tax	$ 6,000		$ 47,000
Comprehensive loss	(8,858,000)	$ (7,077,000)	(23,450,000)	$ (18,487,000)
Collaboration revenue - related party
Collaboration revenue	3,772,000		13,736,000
Collaboration revenue - other
Collaboration revenue	$ 1,903,000		$ 3,575,000

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Series Seed Convertible Preferred Shares	Series A Convertible Preferred Shares	Series B Convertible Preferred Shares	Common units	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Total
Balance at beginning of period at Dec. 31, 2017					$ 661	$ (30,354)		$ (29,693)
Balance at beginning of period ( in shares) at Dec. 31, 2017				1,011,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation expense					123			123
Net loss						(5,179)		(5,179)
Balance at end of period at Mar. 31, 2018					784	(35,533)		(34,749)
Balance at end of period ( in shares) at Mar. 31, 2018				1,011,227
Balance at beginning of period at Dec. 31, 2017	$ 8,658	$ 41,029
Balance at beginning of period ( in shares) at Dec. 31, 2017	2,045,556	6,729,096
Balance at end of period at Mar. 31, 2018	$ 8,658	$ 41,029
Balance at end of period ( in shares) at Mar. 31, 2018	2,045,556	6,729,096
Balance at beginning of period at Dec. 31, 2017					661	(30,354)		(29,693)
Balance at beginning of period ( in shares) at Dec. 31, 2017				1,011,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss								(18,487)
Balance at end of period at Sep. 30, 2018					1,055	(48,841)		(47,786)
Balance at end of period ( in shares) at Sep. 30, 2018				1,011,227
Balance at beginning of period at Dec. 31, 2017	$ 8,658	$ 41,029
Balance at beginning of period ( in shares) at Dec. 31, 2017	2,045,556	6,729,096
Balance at end of period at Sep. 30, 2018	$ 8,658	$ 51,320	$ 79,831
Balance at end of period ( in shares) at Sep. 30, 2018	2,045,556	8,411,368	10,553,483
Balance at beginning of period at Mar. 31, 2018					784	(35,533)		(34,749)
Balance at beginning of period ( in shares) at Mar. 31, 2018				1,011,227
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation expense					135			135
Net loss						(6,231)		(6,231)
Balance at end of period at Jun. 30, 2018					919	(41,764)		(40,845)
Balance at end of period ( in shares) at Jun. 30, 2018				1,011,227
Balance at beginning of period at Mar. 31, 2018	$ 8,658	$ 41,029
Balance at beginning of period ( in shares) at Mar. 31, 2018	2,045,556	6,729,096
Balance at end of period at Jun. 30, 2018	$ 8,658	$ 41,029
Balance at end of period ( in shares) at Jun. 30, 2018	2,045,556	6,729,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation expense					136			136
Net loss						(7,077)		(7,077)
Balance at end of period at Sep. 30, 2018					1,055	(48,841)		(47,786)
Balance at end of period ( in shares) at Sep. 30, 2018				1,011,227
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series A Preferred Units August 10, 2018, net of offering costs of $9		$ 10,291
Issuance of Series A Preferred Units August 10, 2018, net of offering costs of $9 (in shares)		1,682,272
Issuance of Series B Preferred Units September 25, 2018, net of offering costs of $169			$ 79,831
Issuance of Series B Preferred Units September 25, 2018, net of offering costs of $169 (in shares)			10,553,483
Balance at end of period at Sep. 30, 2018	$ 8,658	$ 51,320	$ 79,831
Balance at end of period ( in shares) at Sep. 30, 2018	2,045,556	8,411,368	10,553,483
Balance at beginning of period at Dec. 31, 2018					1,633	(54,185)		(52,552)
Balance at beginning of period ( in shares) at Dec. 31, 2018				1,832,923
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted shares (in shares)				99,911
Equity-based compensation expense					499			499
Unrealized holding gains on marketable securities, net of tax							$ 25	25
Net loss						(5,200)		(5,200)
Balance at end of period at Mar. 31, 2019					2,132	(59,385)	25	(57,228)
Balance at end of period ( in shares) at Mar. 31, 2019				1,932,834
Balance at beginning of period at Dec. 31, 2018	$ 8,658	$ 51,320	$ 79,831
Balance at beginning of period ( in shares) at Dec. 31, 2018	2,045,556	8,411,368	10,553,483
Balance at end of period at Mar. 31, 2019	$ 8,658	$ 51,320	$ 79,831
Balance at end of period ( in shares) at Mar. 31, 2019	2,045,556	8,411,368	10,553,483
Balance at beginning of period at Dec. 31, 2018					1,633	(54,185)		(52,552)
Balance at beginning of period ( in shares) at Dec. 31, 2018				1,832,923
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss								(23,497)
Balance at end of period at Sep. 30, 2019				$ 3	236,980	(77,682)	47	159,348
Balance at end of period ( in shares) at Sep. 30, 2019				30,034,268
Balance at beginning of period at Dec. 31, 2018	$ 8,658	$ 51,320	$ 79,831
Balance at beginning of period ( in shares) at Dec. 31, 2018	2,045,556	8,411,368	10,553,483
Balance at end of period ( in shares) at Sep. 30, 2019	0
Balance at beginning of period at Mar. 31, 2019					2,132	(59,385)	25	(57,228)
Balance at beginning of period ( in shares) at Mar. 31, 2019				1,932,834
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted shares (in shares)				112,165
Equity-based compensation expense					667			667
Unrealized holding gains on marketable securities, net of tax							16	16
Net loss						(9,433)		(9,433)
Balance at end of period at Jun. 30, 2019					2,799	(68,818)	41	$ (65,978)
Balance at end of period ( in shares) at Jun. 30, 2019				2,044,999
Balance at beginning of period at Mar. 31, 2019	$ 8,658	$ 51,320	$ 79,831
Balance at beginning of period ( in shares) at Mar. 31, 2019	2,045,556	8,411,368	10,553,483
Balance at end of period at Jun. 30, 2019	$ 8,658	$ 51,320	$ 79,831
Balance at end of period ( in shares) at Jun. 30, 2019	2,045,556	8,411,368	10,553,483
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock into common stock (in shares)								21,010,407
Issuance of common shares at initial public offering, net of offering costs of $10.1 million (in shares)								6,900,000
Balance at end of period ( in shares) at Jul. 01, 2019								0
Balance at beginning of period at Jun. 30, 2019					2,799	(68,818)	41	$ (65,978)
Balance at beginning of period ( in shares) at Jun. 30, 2019				2,044,999
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock into common stock				$ 2	139,807			139,809
Conversion of convertible preferred stock into common stock (in shares)				21,010,407
Reclassification of warrants to purchase preferred shares to stockholder's equity					118			118
Issuance of common shares at initial public offering, net of offering costs of $10.1 million				$ 1	93,267			93,268
Issuance of common shares at initial public offering, net of offering costs of $10.1 million (in shares)				6,900,000
Issuance of common shares upon warrant exercise (in shares)				5,766
Vesting of restricted shares (in shares)				73,096
Equity-based compensation expense					989			989
Unrealized holding gains on marketable securities, net of tax							6	6
Net loss						(8,864)		(8,864)
Balance at end of period at Sep. 30, 2019				$ 3	$ 236,980	$ (77,682)	$ 47	$ 159,348
Balance at end of period ( in shares) at Sep. 30, 2019				30,034,268
Balance at beginning of period at Jun. 30, 2019	$ 8,658	$ 51,320	$ 79,831
Balance at beginning of period ( in shares) at Jun. 30, 2019	2,045,556	8,411,368	10,553,483
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock into common stock	$ (8,658)	$ (51,320)	$ (79,831)
Conversion of convertible preferred stock into common stock (in shares)	(2,045,556)	(8,411,368)	(10,553,483)
Balance at end of period ( in shares) at Sep. 30, 2019	0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Common units
Offering costs	$ 10,200
Series A Convertible Preferred Shares
Offering costs		$ 9
Series B Convertible Preferred Shares
Offering costs		$ 169

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (23,497)	$ (18,487)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	576	395
Premium amortization and discount accretion on marketable securities	(1,556)
Equity-based compensation	2,155	394
Non-cash interest expense		26
Change in fair value of warrants	94
Change in operating assets and liabilities:
Accounts receivable	(2,364)
Prepaid expenses and other current assets	(1,704)	8
Other assets	12	(9)
Accounts payable	1,540	864
Accrued expenses	1,812	591
Deferred revenue	(4,570)
Deferred rent	(41)	(17)
Other long-term liabilities	(33)	13
Net cash used in operating activities	(27,576)	(16,222)
Cash flows from investing activities:
Purchases of marketable securities	(225,836)
Proceeds from maturities of marketable securities	135,500
Purchase of property and equipment	(1,449)	(492)
Net cash used in investing activities	(91,785)	(492)
Cash flows from financing activities:
Repayment of debt		(247)
Proceeds from issuance of Common Stock, net	93,267
Proceeds from issuance of Preferred Stock, net		90,122
Net cash provided by financing activities	93,267	89,875
Net (decrease) increase in cash and cash equivalents and restricted cash	(26,094)	73,161
Cash and cash equivalents and restricted cash, beginning of period	186,176	21,025
Cash and cash equivalents and restricted cash, end of period	160,082	94,186
Non-cash financing activities:
Reclassification of warrants to additional paid-in capital	118
Conversion of preferred shares to common stock	139,807
Supplemental cash flow information:
Cash paid for taxes	$ 550
Cash paid for interest		$ 19

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Nature of the Business and Basis of Presentation
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Organization Morphic Holding, Inc. was f ormed under the laws of the State of Delaware in August 2014 under the name Integrin Rock, LLC. The Company subsequently changed its name to Morphic Rock Holding, LLC in October 2014 and then to Morphic Holding, LLC in June 2016. On December 5, 2018, the Company completed a series of transactions (the “Reorganization”) pursuant to which Morphic Holding, LLC was converted in a tax free reorganization into Morphic Holding, Inc. and three wholly-owned subsidiaries, namely Lazuli, Inc., Tourmaline, Inc, and Phyllite, Inc, were merged with and into another wholly-owned subsidiary, Morphic Therapeutic, Inc. As part of the Reorganization, all convertible preferred units and common units of Morphic Holding, LLC issued and outstanding immediately prior to the Reorganization were exchanged for shares of Morphic Holding Inc. capital stock of the same class or series on a one-for-one basis. Previously outstanding vested and unvested incentive units, irrespective of threshold amounts (defined as the fair value of common unit on the date the incentive unit award is granted) or voting rights, were exchanged for an equal number of shares of common stock or restricted common stock, respectively. The restricted common stock was issued with the same vesting terms as the unvested incentive units held immediately prior to the Reorganization. Upon consummation of the Reorganization, the historical consolidated financial statements of Morphic Holding, LLC became the historical consolidated financial statements of Morphic Holding Inc. Except as otherwise indicated or the context otherwise requires, all information included in this filing is presented giving effect to the Reorganization. At the time of the Reorganization, the Company created a Massachusetts Securities Corporation (the “Security Corporation”) to take advantage of the favorable tax treatment of income earned on securities held within such entity. As of September 30, 2019, all of the Company’s excess funds were invested through the Security Corporation. The Company is a biopharmaceutical company applying proprietary insights into integrin medicine to discover and develop first-in-class oral small molecule integrin therapeutics. Integrins are a validated target class with multiple approved drugs for the treatment of serious chronic diseases. Despite significant biopharmaceutical industry investment, no oral integrin therapies have been approved. The Company has created the Morphic integrin technology platform, or MInT Platform, by leveraging our unique understanding of integrin structure and biology, to develop a pipeline of novel product candidates designed to achieve potency, high selectivity, and the pharmaceutical properties required for oral administration. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The Company expects to continue to incur losses from operations for the foreseeable future; the Company expects that its cash and cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements through at least the next 12 months from the date these financial statements were issued. On July 1, 2019, the Company completed an IPO, in which the Company issued and sold 6,900,000 shares of its common stock at a public offering price of $15.00 per share, including 900,000 shares of common stock sold pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock, for aggregate gross proceeds of $103.5 million. The Company raised approximately $93.3 million in net proceeds after deducting underwriting discounts and commissions and offering expenses payable by the Company . Upon the closing of the IPO, all of the outstanding shares of convertible preferred stock automatically converted into 21,010,407 shares of common stock; the warrants to purchase 6,825 convertible preferred shares automatically converted in to warrants to purchase 6,825 common shares. Subsequent to the closing of the IPO, there were no shares of preferred stock outstanding. In connection with the closing of the IPO, the Company amended and restated its Fourth Amended and Restated Certificate of Incorporation to change the authorized capital stock to 400,000,000 shares designated as common stock, and 10,000,000 shares designated as preferred stock, all with a par value of $0.0001 per share. Basis of Presentation The consolidated financial statements include the accounts of Morphic Holding, Inc. and its wholly owned subsidiaries described above. All intercompany balances have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited interim financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair presentation of the Company's financial position as of September 30, 2019 and the results of its operations for the three and nine months ended September 30, 2019 and 2018 and its cash flows for the nine months ended September 30, 2019 and 2018. Financial statement disclosures for the nine months ended September 30, 2019 and 2018 are condensed and do not include all disclosures required for an annual set of financial statements in accordance with GAAP and should be read in conjunction with the Company’s audited financial statements and notes in the prospectus filed with the Securities and Exchange Commission on June 27, 2019. The results for the three and nine months ended September 30, 2019 are not necessarily indicative of results to be expected for the year ended December 31, 2019, any other interim periods, or any future year or period.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates and Judgements The preparation of financial statements in accordance with GAAP requires management to make estimates and judgments that may affect the reported amounts of assets and liabilities and related disclosures of contingent assets and liabilities at the date of the financial statements and the related reporting of revenues and expenses during the reporting period. Significant estimates of accounting reflected in these consolidated financial statements include, but are not limited to, estimates related to revenue recognition, accrued research and development expenses, the valuation of equity‑based compensation, including incentive units, restricted common stock, and stock options, and income taxes. Actual results could differ from those estimates. Concentration of Credit Risk and Off‑Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents, marketable securities, and accounts receivable under Janssen agreement. The Company has all cash and cash equivalents at one accredited financial institution, in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The primary objectives for the Company’s investment portfolio are the preservation of capital and maintenance of liquidity. In 2019, the Company adopted its investment policy which allows funds to be held outside bank accounts, but to be invested only in readily marketable fixed income instruments with readily ascertainable market values, denominated and payable in U.S. dollars including obligations of the U.S. government and its agencies and money market funds registered according to Rule 2a‑7 of the Investment Company Act of 1940. Investments in the money market fund shall be consistent with approved instruments and assets under management must be at least $1 billion. The Company has no off‑balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign‑hedging arrangements. Cash and Cash Equivalents and Restricted Cash The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. At September 30, 2019, cash and cash equivalents include bank demand deposits and money market funds that invest primarily in U.S. government‑backed securities and treasuries. Cash equivalents are stated at fair value. Restricted cash consists of a letter of credit in the amount of $275,000 issued to the landlord of the Company’s facility lease. The terms of the letter of credit extend beyond one year. The following table reconciles cash and cash equivalents and restricted cash per the balance sheet to the statements of cash flows: September 30, December 31, September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 159,807 $ 185,901 $ 93,911 $ 20,750 Restricted cash 275 275 275 275 $ 160,082 $ 186,176 $ 94,186 $ 21,025 Marketable securities The Company invests funds in the United States Treasury securities; those securities are included in the current assets based on their contractual maturities, classified as available-for-sale, and carried at fair value. Changes in fair value of marketable securities are recorded in other comprehensive income (loss) as net unrealized gains (losses) on marketable securities. The Company recognized $6,000 and $47,000 in unrealized gains, net for the three and nine months ended September 30, 2019, respectively. The Company held no marketable securities prior to 2019. Interest income on investments The Company recognizes interest income from investments in money market funds and available-for-sale securities, including amortization of premium/accretion of discount, on an accrual basis. For the three and nine months ended September 30, 2019 , the Company recognized $1.4 million and $3.6 million in interest income, respectively. For the three and nine months ended September 30, 2018, the Company recognized $111,000 and $214,000 in interest income, respectively. Interest income is included with other income on the condensed consolidated statements of operations and comprehensive loss. Fair Value Measurements ASC Topic 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that 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. ASC 820 identifies fair value as the exchange price, or 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 a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three‑tier fair value hierarchy that distinguishes between the following: Level 1 — Quoted market prices in active markets for identical assets or liabilities. Level 2 — Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3 — Unobservable inputs developed using estimates of assumptions developed by the Company, which reflect those that a market participant would use. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company believes that the carrying amounts of the Company’s consolidated financial instruments, including prepaid expenses and other current assets, accounts receivable, accounts payable, and accrued expenses approximate fair value due to the short-term nature of those instruments. Comprehensive Loss Comprehensive loss is the change in equity of a business enterprise during a period from transactions and other events and circumstances from non‑owner sources. Comprehensive loss includes net loss and the change in accumulated other comprehensive loss for the period. For the three and nine months ended September 30, 2019, comprehensive loss included $6,000 and $47,000 in unrealized holding gains on marketable securities, respectively; for the three and nine months ended September 30, 2018, comprehensive loss equaled net loss. Recently Adopted Accounting Pronouncements In January 2016, the FASB issued ASU 2016-01, Financial Instruments — Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01), which amended the guidance on the recognition and measurement of financial assets and financial liabilities. The new guidance requires that equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) are measured at fair value with changes in fair value recognized in net income. The guidance also requires the use of an exit price when measuring the fair value of financial instruments for disclosure purposes, eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost and requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset. The guidance became effective for the Company for the fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Adoption of ASU 2016-01 did not have a material impact on the Company's consolidated financial statements. Recently Issued Accounting Pronouncements not yet Adopted As an "emerging growth company," or EGC, under the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, the Company has made an election under Section 107 of the JOBS Act to take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act, for complying with new or revised accounting standards. Thus, the Company follows requirements applicable to the private companies for adopting new and updated accounting standards. In April 2019, the FASB issued ASU 2019-04, Financial Instruments-Credit Losses , Topic 815, Derivatives and Hedging , and Topic 825, Financial Instruments (“ASU 2019-04”). Certain provisions of ASU 2019-04 amend the guidance of ASU 2016-13, are applicable to the Company’s investments portfolio, and allow the Company to make certain accounting policy elections regarding establishing allowance for credit losses for the accrued interest receivable and the corresponding disclosures. The guidance is effective for the fiscal year beginning January 1, 2021, and interim periods within the fiscal year beginning January 2022 and will be adopted using the modified retrospective approach. The Company is currently evaluating the impact of ASU 2019-04 on the consolidated financial statements, including the impact of the available accounting policy elections. In June 2016, the FASB issued ASU 2016-13, Financial Instruments Credit Losses (Topic 326) ("ASU 2016-13"), which requires consideration of a broader range of reasonable and supportable information in developing credit loss estimates. The guidance is effective for the fiscal year beginning January 1, 2021, and interim periods within the fiscal year beginning January 2022 and will be adopted using modified-retrospective approach. The Company is currently evaluating the impact of ASU 2016-13, as amended by ASU 2019-04 described above, on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), with guidance regarding the accounting for and disclosure of leases. This standard is effective for public companies for annual and interim periods beginning after December 15, 2018. For all other entities, this standard is effective for annual reporting periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. In general, for lease arrangements exceeding a twelve-month term, these arrangements must now be recognized as assets and liabilities on the balance sheet of the lessee. Under ASU 2016-02, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of ASU 2016-02 must be calculated using the applicable incremental borrowing rate at the date of adoption. This update also requires lessees and lessors to disclose key information about their leasing transactions. The Company currently expects to elect the available package of practical expedients which allows the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of leases, and the treatment of initial direct costs. The Company also expects it will make an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. In July 2018, the FASB issued ASU 2018-11, Leases - Targeted Improvements , intended to ease the implementation of the new lease standard for financial statement preparers by, among other things, allowing for an additional transition method. In lieu of presenting transition requirements to comparative periods, as previously required, an entity may now elect to show a cumulative effect adjustment on the date of adoption without the requirement to recast prior period financial statements or disclosures presented in accordance with ASU 2016-02. The Company expects to adopt the new standard and elect to use the optional transition method, resulting in no retrospective adjustment to the prior period financial information, effective January 1, 2020, which will be the initial date of application. The Company is in the process of assessing the impact of the standard and while not complete, it expects that it will record a material asset and liability related to its current operating lease, however, the full impact of adoption to the Company’s financial statements is yet to be determined. The Company has considered other recent accounting pronouncements and concluded that they are either not applicable to the business, or that the effect is not expected to be material to the consolidated financial statements as a result of future adoption .

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2019
Fair Value of Financial Assets and Liabilities
Fair Value of Financial Assets and Liabilities	3. Fair Value of Financial Assets and Liabilities The following tables summarize the assets and liabilities measured at fair value on a recurring basis at September 30, 2019 and December 31, 2018 (in thousands): Fair Value Measurements at September 30, 2019 Total Level 1 Level 2 Level 3 Assets: Money market funds, included in cash and cash equivalents $ 159,583 $ 159,583 $ — $ — U.S. Treasury obligations 91,939 — 91,939 — Total assets $ 251,522 $ 159,583 $ 91,939 $ — Fair Value Measurements at December 31, 2018 Total Level 1 Level 2 Level 3 Assets: Money market funds, included in cash and cash equivalents $ 185,676 $ 185,676 $ — $ — Total assets $ 185,676 $ 185,676 $ — $ — The money market funds included in the table above invest in U.S. government securities that are valued using quoted market prices. Accordingly, money market funds are categorized as Level 1 as of September 30, 2019 and December 31, 2018. Marketable securities, included in the table above, consist exclusively of U.S. Treasury securities that are valued using matrix pricing compiled by third party pricing vendors, using observable market inputs such as interest rates, yield curves, and credit risk. Accordingly, these securities are categorized as Level 2 as of September 30, 2019. The Company held no marketable securities as of December 31, 2018.

Marketable securities

Marketable securities	9 Months Ended
	Sep. 30, 2019
Marketable securities.
Marketable securities	4. Marketable securities As of September 30, 2019, the Company had the following investments in marketable securities classified as available for sale (in thousands): Gross Gross Aggregate Amortized unrealized unrealized estimated Maturity cost holding gains holding losses fair value U.S. Treasury securities less than 1 year $ 91,879 $ $ - $ 91,939 As of September 30, 2019, the Company held no marketable securities in an unrealized loss position. The Company did not have any investments in marketable securities at December 31, 2018. the value.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2019
Accrued Expenses
Accrued Expenses	5. Accrued Expenses At September 30, 2019 and December 31, 2018 accrued expenses consist of the following (in thousands): September 30, December 31, 2019 2018 Payroll and related expenses 2,099 2,012 Research and development activities 1,785 512 Other expenses 1,167 715 $ 5,051 $ 3,239

Stockholder's Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2019
Stockholder's Equity
Stockholder's Equity	6. Stockholders’ Equity Immediately prior to the closing of the IPO, the Company had 2,585,976 common shares, including 540,977 restricted common shares, and 21,010,407 convertible preferred shares outstanding; all convertible preferred shares automatically converted into 21,010,407 shares of common stock upon closing of the IPO. As of September 30, 2019, the Company had 400,000,000 common shares authorized and 30,034,268 common shares issued and outstanding and 10,000,000 preferred shares authorized, none of which were outstanding. Cashless Exercise of Warrants In connection with a credit facility entered into in 2016, on March 31, 2016, the Company issued a warrant to SVB to purchase 3,409 Series Seed convertible preferred units at a purchase price of $4.39 per unit, and on December 31, 2016 the Company issued a warrant to purchase 3,416 Series Seed preferred units at a purchase price of $4.39, which became exercisable for 6,825 shares of common stock at a purchase price of $4.39 per share in connection with the IPO. The credit facility was paid off in full by the Company in 2018. In August 2019, SVB exercised warrants via a cashless exercise and the Company issued 5,766 common shares. Shares Reserved for Future Issuance As of September 30, 2019, the Company had reserved common shares for future issuance under the 2019 Stock Option and Incentive Plan and the 2019 Employee Stock Purchase Plan (described in note 7 below) as follows: As of September 30, 2019 Common shares reserved for issuance under the 2019 ESPP 300,000 Common shares reserved for exercise of outstanding stock options under the 2019 Plan 2,680,835 Common shares reserved for future issuance under the 2019 Plan 2,374,981 5,355,816

Equity Based Compensation

Equity Based Compensation	9 Months Ended
	Sep. 30, 2019
Equity Based Compensation
Equity Based Compensation	7. Equity Based Compensation 2019 Stock Incentive Plan The 2019 Stock Incentive Plan (the “2019 Plan”) was approved by the Board of Directors on June 10, 2019 and replaced the 2018 Stock Incentive Plan (the “2018 Plan”), previously instituted as part of the Reorganization. The 2018 Plan provided for the grant of incentive stock options, non-qualified stock options, and restricted stock awards. As of December 31, 2018, there were 3,818,816 shares authorized under the 2018 Plan and 457,438 shares were reserved for future issuance. The 2019 Plan provides for the grant of stock options, restricted stock awards, stock bonus awards, cash awards, stock appreciation right, RSUs, and performance awards to purchase up to 2.8 million shares of common stock. The number of shares reserved for issuance under the Company’s 2019 Plan will increase automatically on January 1 of each of 2020 through 2029 by the number of shares equal to the lesser of 4% of the aggregate number of outstanding shares of the Company’s common stock as of the immediately preceding December 31, or a number as may be determined by the Company’s board of directors. The 2019 Plan is administered by the Board of Directors, or at the discretion of the Board of Directors, by a committee of the board. The exercise prices, vesting, and other restrictions are determined at the discretion of the Board of Directors, or a committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of stock option may not be greater than ten years. The shares of common stock underlying any awards that are forfeited, cancelled, repurchased, or are otherwise terminated by the Company under the 2019 Plan will be added back to the shares of common stock available for issuance under the 2019 Plan. Options generally vest over a four-year period with the first 25% vesting following 12 months of employment or service and the remaining award vesting in equal monthly installments over the following 36 months. All options have a contractual term of 10 years. Restricted Common Stock The following table summarizes the stock and restricted common stock activity under the 2019 Plan during the nine months ended September 30, 2019: Weighted Average Fair Value per Share Number of Shares at Issuance Unvested restricted common stock as of December 31, 2018 753,053 $ 4.32 Granted — $ — Vested (285,172) $ 4.32 Forfeited (18,628) $ 4.32 Unvested restricted common stock as of September 30, 2019 449,253 $ 4.32 As of September 30, 2019, the Company had unrecognized equity‑based compensation expense of $1,119,000, which includes $392,000 related to the modification affected as part of the Reorganization for the restricted common shares issued to employees and non-employees, which is expected to be recognized over a weighted average period of 1 year. The Company recognized equity-based compensation expense for the restricted common stock of $162,000 and $577,000 during the three and nine months ended September 30, 2019, respectively. The Company recognized equity-based expense for the restricted incentive units of $136,000 and $394,000 during the three and nine months ended September 30, 2018, respectively. Stock Options The Company granted stock option awards under the 2019 Plan. The following table summarizes the Company’s stock option activity under the 2019 Plan during the nine months ended September 30, 2019: Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Price Contractual Term Intrinsic Value (in years) (in thousands) Outstanding as of December 31, 2018 1,786,551 $ 4.32 9.96 $ — Granted 907,178 14.73 — — Exercised — — — — Forfeited (12,894) 4.32 — — Outstanding as of September 30, 2019 2,680,835 $ 7.84 9.39 $ 28,098 Options exercisable as of September 30, 2019 325,651 $ 4.44 9.21 $ 4,452 The weighted average grant‑date fair value per share of stock options granted to employees and non-employees for stock option awards with service‑based vesting conditions during the nine months ended September 30, 2019 was $9.75 per share. The following table summarizes assumptions used in determining the fair value of the options granted in 2019: Risk‑free interest rate 1.91 Expected dividend yield — Expected term (in years) 6.01 Expected Volatility 74.96% The Company determined the volatility for options granted in 2019 based on reported data for a guideline group of companies that issued options with substantially similar terms. The risk-free interest rate is based on a zero-coupon United States Treasury instrument with terms consistent with the expected life of the stock options. The expected term of options granted by us has been determined based upon the simplified method, because we do not have sufficient historical information regarding our options to derive the expected term. Under this approach, the expected term is the mid-point between the weighted average of vesting period and the contractual term. The Company has not paid and does not anticipate paying cash dividends on shares of common stock; therefore, the expected dividend yield is assumed to be zero. Compensation Expense related to Stock Options The Company recorded equity-based compensation expense for stock options granted to employees and non-employees of $707,000 and $1,457,000 for the three and nine months ended September 30, 2019, respectively. The Company did not recognize equity-based compensation expense related to stock options for the three and nine months ended September 30, 2018 as no such awards were granted and outstanding as of September 30, 2018. As of September 30, 2019, the Company had unrecognized equity‑based compensation expense of $12.4 million related to stock options issued to employees and non-employees, which is expected to be recognized over a weighted average period of 3.36 years. 2019 Employee Stock Purchase Plan In June 2019, the Company adopted the 2019 Employee Stock Purchase Plan (“ESPP”), which became effective on June 26, 2019. The Company initially reserved 300,000 shares of common stock for sale under the ESPP. The number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first 10 calendar years following the first offering date by the number of shares equal to the lesser of 1% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31 or an amount determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP will not exceed 3,000,000 shares of the Company’s common stock. The ESPP is a qualified, compensatory plan under Section 423 of the Internal Revenue Code and offers substantially all employees opportunity to purchase up to $25,000 of common stock per year at 15% discount to the lower of the beginning of the offering period price or the end of the offering period price. Compensation expense for discounted purchases under the ESPP is measured using the Black-Scholes model to compute the fair value of the lookback provision plus the purchase discount and is recognized as compensation expense over the course of the offering period. During the three and nine months ended September 30, 2019, the Company granted awards with the weighted average grant date fair value of $5.30 and recognized $120,000 in compensation expense related to the discount offered under the 2019 ESPP. The Company recognized no expense in the comparable periods of 2018. Total Equity‑based Compensation Expense The Company recorded equity‑based compensation expense related to all equity‑based awards for employees and non‑employees, which was allocated as follows in the condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Research and development expense $ 586 $ 81 $ 1,287 $ 230 General and administrative expense 403 55 867 164 $ 989 $ 136 $ 2,154 $ 394

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Taxes
Income Taxes	8. Income Taxes The Company records income tax expense in any interim period based on the estimated effective tax rate for the fiscal year for those tax jurisdictions in which the Company can reliably estimate that rate. The calculation of the estimated effective tax rate requires an estimate of pre-tax income by tax jurisdiction as well as total tax expense for the fiscal year. Accordingly, the annual estimated effective tax rate is subject to adjustment if there are changes to the initial estimates of total tax expense or pre-tax income. Provision for Income Taxes The Company recorded an income tax expense of $304,000 and $0 for the three months ended September 30, 2019 and 2018, respectively. The Company recorded an income tax expense of $569,000 and $0 for the nine months ended September 30, 2019 and 2018, respectively. In the three and nine months ended September 30, 2019, the income tax expense recorded was driven largely by the projected current tax liability associated with the tax recognition of the upfront AbbVie collaboration payment received in 2018. A significant portion of the taxable income related to the collaboration payments is projected to be offset by current year expenses and prior year accumulated losses. A current tax liability has been projected for the remaining taxable income. The Company reported no income tax provision in the three and nine months ended September 30, 2018, as the Company generated a taxable loss, offset by an increase to the Company’s valuation allowance. Despite the collaboration revenue, the Company continues to maintain a valuation allowance against all deferred tax assets. The Company believes that it is more likely than not that the Company will not realize a future tax benefit of these attributes, as the research programs continue to require significant investment and future revenue is subject to uncertainties. Ultimate realization of any deferred tax asset is dependent on the Company’s ability to generate sufficient future taxable income in the appropriate tax jurisdiction before the expiration of carryforward periods, if any. The Company currently anticipates that there will be no change in its unrecognized tax benefits in the next twelve months. As of September 30, 2019, the Company had no unrecognized tax benefits. The Company has not yet conducted a study of its research and development credit carryforwards. Such a study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amount is being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits, and, if an adjustment is required, this adjustment would be offset by an adjustment to the valuation allowance. Thus, there would be no impact to the balance sheet or statement of operations and comprehensive loss if an adjustment were required.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies
Commitments and Contingencies	9. Commitments and Contingencies Guarantees and Indemnifications The Company entered, and intends to continue to enter, into separate indemnification agreements with directors, officers, and certain of key employees, in addition to the indemnification provided for in the restated certificate of incorporation and restated bylaws. These agreements, among other things, require the Company to indemnify directors, officers, and key employees for certain expenses, including attorneys' fees, judgments, penalties, fines, and settlement amounts actually incurred by these individuals in any action or proceeding arising out of their service to the Company or any of its subsidiaries or any other company or enterprise to which these individuals provide services at the Company’s request. Subject to certain limitations, the indemnification agreements also require the Company to advance expenses incurred by directors, officers, and key employees for the defense of any action for which indemnification is required or permitted. The Company has standard indemnification arrangements in its leases for laboratory and office space that require it to indemnify the landlord against any liability for injury, loss, accident, or damage from any claims, actions, proceedings, or costs resulting from certain acts, breaches, violations, or non-performance under the Company’s lease. Through September 30, 2019, the Company had not experienced any losses related to these indemnifications obligations, and no material claims were outstanding. The Company does not expect significant claims related to these indemnifications’ obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves were established. Operating Leases Facility Lease The Company recognizes rent expense for the space it currently occupies and records a deferred rent obligation, representing the cumulative difference between actual rent payments and rent expense recognized ratably over the lease period, which is included in the Company’s consolidated balance sheets as of December 31, 2018 and September 30, 2019. Minimum annual rent payments under this lease for the remaining term of the amended lease, excluding operating expenses and taxes, which are not fixed for future periods as of September 30, 2019, are as follows (in thousands): Total Minimum Sublease Net Minimum Year ending December 31, Lease Payments Income Lease Payments 2019 $ 274 $ (20) $ 254 2020 1,122 (83) 1,039 2021 1,175 — 1,175 2022 495 — 495 Total minimum lease payments $ 3,066 $ (103) $ 2,963 The Company recorded approximately $237,000 and $223,000 in rent expense for the three months ended September 30, 2019 and 2018, respectively, and $684,000 and $724,000 in rent expense for the nine months ended September 30, 2019 and 2018, respectively. Legal Proceedings The Company is not currently a party to any material legal proceedings.

Option and License Agreement

Option and License Agreement	9 Months Ended
	Sep. 30, 2019
Option and License Agreement
Option and License Agreement	10. Option and License Agreements Detailed description of contractual terms and the Company’s accounting for agreements described below were included in the Company’s audited financial statements and notes in the prospectus filed with the Securities and Exchange Commission on June 27, 2019 AbbVie Agreement During the three and nine months ended September 30, 2019, the Company continued to perform under its agreement with AbbVie, a research-based global biopharmaceutical company and an investor holding approximately 3.3% of the Company’s common stock. During the three months ended September 30, 2019, the Company incurred $4.6 million in research and development costs and recognized revenue of $3.8 million related to research services performed during the period. During the nine months ended September 30, 2019, the Company incurred $15.3 million in research and development costs and recognized revenue of $13.7 million related to research services performed during the period. As of September 30, 2019, the Company has $82.9 million of deferred revenue, which is classified as either current or long-term deferred revenue in the accompanying consolidated balance sheets based on the period over which the revenue is expected to be recognized. This deferred revenue balance represents the aggregate amount of the transaction price allocated to the performance obligations that are partially unsatisfied as of September 30, 2019. The Company expects to recognize revenue related to these performance obligations through 2024. As the Company progresses towards satisfaction of performance obligations under the AbbVie agreement, the estimated costs associated with the remaining effort required to complete the performance obligations may change, which may impact revenue recognition. The Company regularly evaluates and, when necessary, updates the costs associated with the remaining effort associated with each performance obligation under the AbbVie agreement. Accordingly, revenue may fluctuate from period to period due to revisions to estimated costs as a percentage of the total budget, also impacting the allocation of deferred revenue between current and long term based on changes in expected timing of the satisfaction of performance obligations. During the quarter, the Company made such revisions to its estimated costs, and therefore reduced the amount of revenue recognized by $0.5 million for the performance obligations satisfied during the period. On November 12, 2019, the Company announced that it’s selective oral α v β 6 specific integrin inhibitor program for patients with fibrotic disease, MORF-720, conducted in collaboration with AbbVie, will require additional development activities, extending into the second half of 2020 based on feedback received during pre-IND interactions with the FDA, subsequent to September 30, 2019. As of the date of this filing, any such changes to the development plan have not been determined and the Company believes that it has no better estimate of the future costs to complete its performance obligation for MORF-720 than what was used as of September 30, 2019. Any change in estimated costs to complete the Company’s performance obligations will be determined after upcoming discussions with AbbVie and could result in adjustments to revenue recognized in future periods pursuant to the collaboration and option agreement and such adjustments may be significant. Janssen Agreement During the three months ended September 30, 2019, the Company incurred $1.5 million in research and development costs and recognized revenue of $1.9 million related to research services. During the nine months ended September 30, 2019, the Company incurred $2.7 million in research and development costs and recognized revenue of $3.6 million related to research services. The Company had $2.4 million and $0 due from Janssen included in accounts receivable on the condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018, respectively. As of September 30, 2019, $9.2 million of deferred revenue is classified as either current or long-term deferred revenue in the accompanying consolidated balance sheets based on the period over which the revenue is expected to be recognized. This deferred revenue balance represents the portion of the upfront payment received allocated to the performance obligations that are partially unsatisfied as of September 30, 2019. The Company expects to recognize revenue related to these performance obligations through 2024.

Net Loss per Unit and Share

Net Loss per Unit and Share	9 Months Ended
	Sep. 30, 2019
Net Loss per Unit and Share
Net Loss per Unit and Share	11. Net Loss per Unit and Share Basic and diluted net loss per share is calculated as follows (in thousands, except share and per share data) for the three and nine months ended September 30, 2019: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Net loss $ (8,864) (23,497) Weighted average common shares outstanding, basic and diluted 29,999,170 11,393,192 Net loss per share, basic and diluted $ (0.30) $ (2.06) Following the Reorganization, the Company calculates net loss per share based on its outstanding shares of common stock. For the three and nine months ended September 30, 2018, the weighted average number of common units outstanding includes the weighted average number of common units outstanding prior to the Reorganization. Basic and diluted net loss per unit is calculated as follows (in thousands, except unit and per unit data) for the three and nine months ended September 30, 2018: Three Months Ended Nine Months Ended September 30, 2018 September 30, 2018 Net loss $ (7,077) $ (18,487) Weighted average common units outstanding, basic and diluted 1,011,227 1,011,227 Net loss per unit, basic and diluted $ (7.00) $ (18.28) The following table sets forth the outstanding common unit or common stock equivalents, presented based on amounts outstanding at each period end, that have been excluded from the calculation of diluted net loss per unit or share for the periods indicated because their inclusion would have been anti‑dilutive (in common unit or common stock equivalent shares, as applicable): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Convertible preferred units — 21,010,407 — 21,010,407 Incentive units — 721,499 — 721,499 Restricted common stock 449,253 — 449,253 — Warrant — 6,825 — 6,825 Shares issuable under ESPP 300,000 — 300,000 — Stock options 2,680,835 — 2,680,835 — 3,430,088 21,738,731 3,430,088 21,738,731

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events
Subsequent Events	12. Subsequent Events On November 12, 2019, the Company announced that it’s selective oral α v β 6 specific integrin inhibitor program for patients with fibrotic disease, MORF-720, conducted in collaboration with AbbVie, will require additional development activities, extending into the second half of 2020 based on feedback received during pre-IND interactions with the FDA. See Note 10 for further information.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Summary of Significant Accounting Policies
Use of Estimates and Judgements	Use of Estimates and Judgements The preparation of financial statements in accordance with GAAP requires management to make estimates and judgments that may affect the reported amounts of assets and liabilities and related disclosures of contingent assets and liabilities at the date of the financial statements and the related reporting of revenues and expenses during the reporting period. Significant estimates of accounting reflected in these consolidated financial statements include, but are not limited to, estimates related to revenue recognition, accrued research and development expenses, the valuation of equity‑based compensation, including incentive units, restricted common stock, and stock options, and income taxes. Actual results could differ from those estimates.
Concentration of Credit Risk and Off‑Balance Sheet Risk	Concentration of Credit Risk and Off‑Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents, marketable securities, and accounts receivable under Janssen agreement. The Company has all cash and cash equivalents at one accredited financial institution, in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The primary objectives for the Company’s investment portfolio are the preservation of capital and maintenance of liquidity. In 2019, the Company adopted its investment policy which allows funds to be held outside bank accounts, but to be invested only in readily marketable fixed income instruments with readily ascertainable market values, denominated and payable in U.S. dollars including obligations of the U.S. government and its agencies and money market funds registered according to Rule 2a‑7 of the Investment Company Act of 1940. Investments in the money market fund shall be consistent with approved instruments and assets under management must be at least $1 billion. The Company has no off‑balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign‑hedging arrangements.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. At September 30, 2019, cash and cash equivalents include bank demand deposits and money market funds that invest primarily in U.S. government‑backed securities and treasuries. Cash equivalents are stated at fair value. Restricted cash consists of a letter of credit in the amount of $275,000 issued to the landlord of the Company’s facility lease. The terms of the letter of credit extend beyond one year. The following table reconciles cash and cash equivalents and restricted cash per the balance sheet to the statements of cash flows: September 30, December 31, September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 159,807 $ 185,901 $ 93,911 $ 20,750 Restricted cash 275 275 275 275 $ 160,082 $ 186,176 $ 94,186 $ 21,025
Marketable securities	Marketable securities The Company invests funds in the United States Treasury securities; those securities are included in the current assets based on their contractual maturities, classified as available-for-sale, and carried at fair value. Changes in fair value of marketable securities are recorded in other comprehensive income (loss) as net unrealized gains (losses) on marketable securities. The Company recognized $6,000 and $47,000 in unrealized gains, net for the three and nine months ended September 30, 2019, respectively. The Company held no marketable securities prior to 2019.
Interest income on investments	Interest income on investments The Company recognizes interest income from investments in money market funds and available-for-sale securities, including amortization of premium/accretion of discount, on an accrual basis. For the three and nine months ended September 30, 2019 , the Company recognized $1.4 million and $3.6 million in interest income, respectively. For the three and nine months ended September 30, 2018, the Company recognized $111,000 and $214,000 in interest income, respectively. Interest income is included with other income on the condensed consolidated statements of operations and comprehensive loss.
Fair Value Measurements	Fair Value Measurements ASC Topic 820, Fair Value Measurement (“ASC 820”), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that 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. ASC 820 identifies fair value as the exchange price, or 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 a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three‑tier fair value hierarchy that distinguishes between the following: Level 1 — Quoted market prices in active markets for identical assets or liabilities. Level 2 — Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3 — Unobservable inputs developed using estimates of assumptions developed by the Company, which reflect those that a market participant would use. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company believes that the carrying amounts of the Company’s consolidated financial instruments, including prepaid expenses and other current assets, accounts receivable, accounts payable, and accrued expenses approximate fair value due to the short-term nature of those instruments.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is the change in equity of a business enterprise during a period from transactions and other events and circumstances from non‑owner sources. Comprehensive loss includes net loss and the change in accumulated other comprehensive loss for the period. For the three and nine months ended September 30, 2019, comprehensive loss included $6,000 and $47,000 in unrealized holding gains on marketable securities, respectively; for the three and nine months ended September 30, 2018, comprehensive loss equaled net loss.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In January 2016, the FASB issued ASU 2016-01, Financial Instruments — Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01), which amended the guidance on the recognition and measurement of financial assets and financial liabilities. The new guidance requires that equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) are measured at fair value with changes in fair value recognized in net income. The guidance also requires the use of an exit price when measuring the fair value of financial instruments for disclosure purposes, eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost and requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset. The guidance became effective for the Company for the fiscal year beginning January 1, 2019, including interim periods within that fiscal year. Adoption of ASU 2016-01 did not have a material impact on the Company's consolidated financial statements.
Recently Issued Accounting Pronouncements not yet Adopted	Recently Issued Accounting Pronouncements not yet Adopted As an "emerging growth company," or EGC, under the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, the Company has made an election under Section 107 of the JOBS Act to take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act, for complying with new or revised accounting standards. Thus, the Company follows requirements applicable to the private companies for adopting new and updated accounting standards. In April 2019, the FASB issued ASU 2019-04, Financial Instruments-Credit Losses , Topic 815, Derivatives and Hedging , and Topic 825, Financial Instruments (“ASU 2019-04”). Certain provisions of ASU 2019-04 amend the guidance of ASU 2016-13, are applicable to the Company’s investments portfolio, and allow the Company to make certain accounting policy elections regarding establishing allowance for credit losses for the accrued interest receivable and the corresponding disclosures. The guidance is effective for the fiscal year beginning January 1, 2021, and interim periods within the fiscal year beginning January 2022 and will be adopted using the modified retrospective approach. The Company is currently evaluating the impact of ASU 2019-04 on the consolidated financial statements, including the impact of the available accounting policy elections. In June 2016, the FASB issued ASU 2016-13, Financial Instruments Credit Losses (Topic 326) ("ASU 2016-13"), which requires consideration of a broader range of reasonable and supportable information in developing credit loss estimates. The guidance is effective for the fiscal year beginning January 1, 2021, and interim periods within the fiscal year beginning January 2022 and will be adopted using modified-retrospective approach. The Company is currently evaluating the impact of ASU 2016-13, as amended by ASU 2019-04 described above, on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), with guidance regarding the accounting for and disclosure of leases. This standard is effective for public companies for annual and interim periods beginning after December 15, 2018. For all other entities, this standard is effective for annual reporting periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. In general, for lease arrangements exceeding a twelve-month term, these arrangements must now be recognized as assets and liabilities on the balance sheet of the lessee. Under ASU 2016-02, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of ASU 2016-02 must be calculated using the applicable incremental borrowing rate at the date of adoption. This update also requires lessees and lessors to disclose key information about their leasing transactions. The Company currently expects to elect the available package of practical expedients which allows the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of leases, and the treatment of initial direct costs. The Company also expects it will make an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. In July 2018, the FASB issued ASU 2018-11, Leases - Targeted Improvements , intended to ease the implementation of the new lease standard for financial statement preparers by, among other things, allowing for an additional transition method. In lieu of presenting transition requirements to comparative periods, as previously required, an entity may now elect to show a cumulative effect adjustment on the date of adoption without the requirement to recast prior period financial statements or disclosures presented in accordance with ASU 2016-02. The Company expects to adopt the new standard and elect to use the optional transition method, resulting in no retrospective adjustment to the prior period financial information, effective January 1, 2020, which will be the initial date of application. The Company is in the process of assessing the impact of the standard and while not complete, it expects that it will record a material asset and liability related to its current operating lease, however, the full impact of adoption to the Company’s financial statements is yet to be determined. The Company has considered other recent accounting pronouncements and concluded that they are either not applicable to the business, or that the effect is not expected to be material to the consolidated financial statements as a result of future adoption

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Summary of Significant Accounting Policies
Schedule of reconciliation of cash and cash equivalents and restricted cash	September 30, December 31, September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 159,807 $ 185,901 $ 93,911 $ 20,750 Restricted cash 275 275 275 275 $ 160,082 $ 186,176 $ 94,186 $ 21,025

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value of Financial Assets and Liabilities
Summary of the assets and liabilities measured at fair value on a recurring basis	The following tables summarize the assets and liabilities measured at fair value on a recurring basis at September 30, 2019 and December 31, 2018 (in thousands): Fair Value Measurements at September 30, 2019 Total Level 1 Level 2 Level 3 Assets: Money market funds, included in cash and cash equivalents $ 159,583 $ 159,583 $ — $ — U.S. Treasury obligations 91,939 — 91,939 — Total assets $ 251,522 $ 159,583 $ 91,939 $ — Fair Value Measurements at December 31, 2018 Total Level 1 Level 2 Level 3 Assets: Money market funds, included in cash and cash equivalents $ 185,676 $ 185,676 $ — $ — Total assets $ 185,676 $ 185,676 $ — $ —

Marketable securities (Tables)

Marketable securities (Tables)	9 Months Ended
	Sep. 30, 2019
Marketable securities.
Schedule of investments in marketable securities classified as available for sale	As of September 30, 2019, the Company had the following investments in marketable securities classified as available for sale (in thousands): Gross Gross Aggregate Amortized unrealized unrealized estimated Maturity cost holding gains holding losses fair value U.S. Treasury securities less than 1 year $ 91,879 $ $ - $ 91,939

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Accrued Expenses
Schedule of accrued expenses	At September 30, 2019 and December 31, 2018 accrued expenses consist of the following (in thousands): September 30, December 31, 2019 2018 Payroll and related expenses 2,099 2,012 Research and development activities 1,785 512 Other expenses 1,167 715 $ 5,051 $ 3,239

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Stockholder's Equity
Schedule of shares reserved for future issuance	As of September 30, 2019 Common shares reserved for issuance under the 2019 ESPP 300,000 Common shares reserved for exercise of outstanding stock options under the 2019 Plan 2,680,835 Common shares reserved for future issuance under the 2019 Plan 2,374,981 5,355,816

Equity Based Compensation (Tabl

Equity Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Equity Based Compensation
Summary of common stock and restricted common stock activity	Weighted Average Fair Value per Share Number of Shares at Issuance Unvested restricted common stock as of December 31, 2018 753,053 $ 4.32 Granted — $ — Vested (285,172) $ 4.32 Forfeited (18,628) $ 4.32 Unvested restricted common stock as of September 30, 2019 449,253 $ 4.32
Summary of Company’s stock option activity	Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Price Contractual Term Intrinsic Value (in years) (in thousands) Outstanding as of December 31, 2018 1,786,551 $ 4.32 9.96 $ — Granted 907,178 14.73 — — Exercised — — — — Forfeited (12,894) 4.32 — — Outstanding as of September 30, 2019 2,680,835 $ 7.84 9.39 $ 28,098 Options exercisable as of September 30, 2019 325,651 $ 4.44 9.21 $ 4,452
Summary of assumptions used in determining the fair value of the options granted	The following table summarizes assumptions used in determining the fair value of the options granted in 2019: Risk‑free interest rate 1.91 Expected dividend yield — Expected term (in years) 6.01 Expected Volatility 74.96%
Summary of equity based compensation expense related to all equity based awards for employees and non employees	The Company recorded equity‑based compensation expense related to all equity‑based awards for employees and non‑employees, which was allocated as follows in the condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Research and development expense $ 586 $ 81 $ 1,287 $ 230 General and administrative expense 403 55 867 164 $ 989 $ 136 $ 2,154 $ 394

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies
Summary of minimum annual rent payments under this lease	Minimum annual rent payments under this lease for the remaining term of the amended lease, excluding operating expenses and taxes, which are not fixed for future periods as of September 30, 2019, are as follows (in thousands): Total Minimum Sublease Net Minimum Year ending December 31, Lease Payments Income Lease Payments 2019 $ 274 $ (20) $ 254 2020 1,122 (83) 1,039 2021 1,175 — 1,175 2022 495 — 495 Total minimum lease payments $ 3,066 $ (103) $ 2,963

Net Loss per Unit and Share (Ta

Net Loss per Unit and Share (Tables)	9 Months Ended
	Sep. 30, 2019
Net Loss per Unit and Share
Schedule of Basic and diluted net loss per share	Basic and diluted net loss per share is calculated as follows (in thousands, except share and per share data) for the three and nine months ended September 30, 2019: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Net loss $ (8,864) (23,497) Weighted average common shares outstanding, basic and diluted 29,999,170 11,393,192 Net loss per share, basic and diluted $ (0.30) $ (2.06) Following the Reorganization, the Company calculates net loss per share based on its outstanding shares of common stock. For the three and nine months ended September 30, 2018, the weighted average number of common units outstanding includes the weighted average number of common units outstanding prior to the Reorganization. Basic and diluted net loss per unit is calculated as follows (in thousands, except unit and per unit data) for the three and nine months ended September 30, 2018: Three Months Ended Nine Months Ended September 30, 2018 September 30, 2018 Net loss $ (7,077) $ (18,487) Weighted average common units outstanding, basic and diluted 1,011,227 1,011,227 Net loss per unit, basic and diluted $ (7.00) $ (18.28)
Schedule of outstanding common unit or common stock equivalents that have been excluded from the calculation of diluted net loss per unit or share	The following table sets forth the outstanding common unit or common stock equivalents, presented based on amounts outstanding at each period end, that have been excluded from the calculation of diluted net loss per unit or share for the periods indicated because their inclusion would have been anti‑dilutive (in common unit or common stock equivalent shares, as applicable): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Convertible preferred units — 21,010,407 — 21,010,407 Incentive units — 721,499 — 721,499 Restricted common stock 449,253 — 449,253 — Warrant — 6,825 — 6,825 Shares issuable under ESPP 300,000 — 300,000 — Stock options 2,680,835 — 2,680,835 — 3,430,088 21,738,731 3,430,088 21,738,731

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation (Details) $ / shares in Units, $ in Millions	Jul. 01, 2019USD ($)$ / sharesshares	Sep. 30, 2019subsidiaryshares	Dec. 31, 2018shares
Subsidiary or Equity Method Investee [Line Items]
Number of wholly-owned subsidiaries merged in reorganization | subsidiary		3
Stock conversion ratio		1
Common stock issued (in shares)	6,900,000
Public offering price (in dollars per share) | $ / shares	$ 15
Gross proceeds | $	$ 103.5
Net proceeds | $	$ 93.3
Conversion of convertible preferred stock into common stock (in shares)	21,010,407
Warrants to purchase shares	6,825
Outstanding warrants	6,825
Preferred shares, shares outstanding	0
Common stock, authorized (in shares)	400,000,000	400,000,000	151,000,000
Preferred shares, shares authorized	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.0001
Underwriters' exercise
Subsidiary or Equity Method Investee [Line Items]
Common stock issued (in shares)	900,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Cash and Cash Equivalents and Restricted Cash
Term of letter of credit (in years)	1 year
Cash and cash equivalents	$ 159,807	$ 185,901	$ 93,911	$ 20,750
Restricted cash	275	275	275	275
Cash and Cash Equivalents and Restricted Cash	160,082	$ 186,176	$ 94,186	$ 21,025
Minimum
Concentration of Credit Risk and Off Balance Sheet Risk
Assets under management	$ 1,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Marketable securities and interest income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Marketable securities
Marketable securities gains (losses)	$ 6,000		$ 47,000
Marketable securities	91,939,000		91,939,000		$ 0
Interest income on investments
Interest income	$ 1,400,000	$ 111,000	$ 3,600,000	$ 214,000

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Level 2 | U.S. Treasury obligations
Assets:
Marketable Securities		$ 0
Fair value on a recurring basis
Assets:
Total assets	$ 251,522,000	185,676,000
Fair value on a recurring basis | Money market funds
Assets:
Assets included in cash and cash equivalents	159,583,000	185,676,000
Fair value on a recurring basis | U.S. Treasury obligations
Assets:
Assets included in cash and cash equivalents	91,939,000
Fair value on a recurring basis | Level 1
Assets:
Total assets	159,583,000	185,676,000
Fair value on a recurring basis | Level 1 | Money market funds
Assets:
Assets included in cash and cash equivalents	159,583,000	$ 185,676,000
Fair value on a recurring basis | Level 2
Assets:
Total assets	91,939,000
Fair value on a recurring basis | Level 2 | U.S. Treasury obligations
Assets:
Assets included in cash and cash equivalents	$ 91,939,000

Marketable securities (Details)

Marketable securities (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Marketable securities
Aggregate estimated fair value	$ 91,939,000	$ 0
Unrealized loss position	0
U.S. Treasury obligations
Marketable securities
Amortized cost	91,879,000
Gross unrealized holding gains	60,000
Aggregate estimated fair value	$ 91,939,000

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accrued Expenses
Payroll and related expenses	$ 2,099	$ 2,012
Research and development activities	1,785	512
Other expenses	1,167	715
Total	$ 5,051	$ 3,239

Stockholder's Equity (Details)

Stockholder's Equity (Details) - shares	9 Months Ended
	Sep. 30, 2019	Jul. 01, 2019	Jun. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Shares outstanding		0
Common stock, authorized	400,000,000	400,000,000		151,000,000
Common Stock, Shares, Issued	30,034,268			1,832,923
Common shares, shares outstanding	30,034,268			1,832,923
Preferred shares, shares authorized	10,000,000			10,000,000
Preferred shares, shares outstanding	0			0
IPO
Class of Stock [Line Items]
Outstanding Shares			2,585,976
Shares outstanding			21,010,407
Conversion of convertible preferred stock into common stock	21,010,407
Restricted common stock | IPO
Class of Stock [Line Items]
Outstanding Shares			540,977

Stockholder's Equity - Warrants

Stockholder's Equity - Warrants (Details) - $ / shares	1 Months Ended
	Aug. 31, 2019	Jul. 01, 2019	Dec. 31, 2016	Mar. 31, 2016
Class of Warrant or Right [Line Items]
Warrants to purchase shares		6,825
Warrants		6,825
Series Seed Preferred Shares
Class of Warrant or Right [Line Items]
Warrants to purchase shares			3,416	3,409
Exercise price			$ 4.39	$ 4.39
Common shares
Class of Warrant or Right [Line Items]
Warrants to purchase shares			6,825
Exercise price			$ 4.39
Number of shares issued	5,766

Stockholder's Equity - Shares r

Stockholder's Equity - Shares reserved for future issuance (Details)	Sep. 30, 2019shares
Class of Stock [Line Items]
Shares available for future issuance	5,355,816
2019 stock option plan
Class of Stock [Line Items]
Shares available for future issuance	2,680,835
2019 stock option and incentive plan
Class of Stock [Line Items]
Shares available for future issuance	2,374,981
Warrants | 2019 ESPP
Class of Stock [Line Items]
Shares available for future issuance	300,000

Equity Based Compensation (Deta

Equity Based Compensation (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Equity Based Compensation
Shares authorized		2,800,000		2,800,000
Percentage of increase in authorized shares				4.00%
Equity based compensation expense		$ 989,000	$ 136,000	$ 2,154,000	$ 394,000
Shares issuable under ESPP
Equity Based Compensation
Shares authorized	300,000
Percentage of increase in authorized shares	1.00%
Discount rate to purchase common stock	15.00%
Equity based compensation expense		$ 120,000	$ 0	$ 120,000	$ 0
Weighted Average Threshold Price per Unit
Granted (in dollars per share)		$ 5.30		$ 5.30
Shares issuable under ESPP | Maximum
Equity Based Compensation
Shares authorized	3,000,000
Common shares available for purchase	25,000
2018 Stock Incentive Plan
Equity Based Compensation
Shares authorized						3,818,816
Shares available for future grants						457,438

Equity Based Compensation - 201

Equity Based Compensation - 2019 stock incentive plan (Details)	9 Months Ended
	Sep. 30, 2019shares
Equity Based Compensation
Shares available for future issuance	5,355,816
Stock options
Equity Based Compensation
Percentage of exercise price of option over fair market value of shares	100.00%
Vesting period	4 years
Vesting percentage	25.00%
Stock options | Initial vesting following 12 months of employment or service
Equity Based Compensation
Vesting period	12 months
Stock options | Remaining vesting in equal quarterly installments over the following 36 months
Equity Based Compensation
Vesting period	36 months
Stock options | Maximum
Equity Based Compensation
Contractual term	10 years

Equity Based Compensation - Com

Equity Based Compensation - Common stock and restricted common stock activity (Details) - USD ($)	3 Months Ended		9 Months Ended		10 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019
Weighted Average Grant Date Fair Value per Unit
Equity based compensation expense	$ 989,000	$ 136,000	$ 2,154,000	$ 394,000
Restricted common stock
Number of Shares
Outstanding at the beginning					753,053
Vested					(285,172)
Forfeited					(18,628)
Outstanding at the end	449,253		449,253		449,253
Weighted Average Grant Date Fair Value per Unit
Outstanding at the beginning (in dollars per share)					$ 4.32
Vested as of the Reorganization					4.32
Forfeited (in dollars per share)					4.32
Outstanding at the end (in dollars per share)	$ 4.32		$ 4.32		$ 4.32
Unrecognized equity based compensation expense	$ 1,119,000		$ 1,119,000		$ 1,119,000
Unrecognized equity based compensation expense related to modification			$ 392,000
Unrecognized equity based compensation expense expected period for recognition			1 year
Equity based compensation expense	$ 162,000	$ 136,000	$ 577,000	$ 394,000

Equity Based Compensation - Sto

Equity Based Compensation - Stock option awards (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Assumptions used in determining the fair value of the options granted
Total Equity based Compensation Expense	$ 989,000	$ 136,000	$ 2,154,000	$ 394,000
Stock options
Number of Shares
Outstanding at the beginning			1,786,551
Granted			907,178
Forfeited			(12,894)
Outstanding at the end	2,680,835		2,680,835		1,786,551
Options exercisable at the end	325,651		325,651
Weighted Average Exercise Price
Outstanding at the beginning (in dollars per share)			$ 4.32
Granted (in dollars per share)			14.73
Forfeited (in dollars per share)			4.32
Outstanding at the end (in dollars per share)	$ 7.84		7.84		$ 4.32
Options exercisable at the end (in dollars per share)	$ 4.44		$ 4.44
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value
Expected term (in years)			9 years 4 months 21 days		9 years 11 months 16 days
Options exercisable at the end (in years)			9 years 2 months 16 days
Outstanding at the end (in dollars)	$ 28,098,000		$ 28,098,000
Options exercisable at the end (in dollars)	4,452,000		$ 4,452,000
Weighted average grant date fair value per share of stock options granted to employees and non-employees for stock option awards			$ 9.75
Assumptions used in determining the fair value of the options granted
Risk-free interest rate			1.91%
Expected term (in years)			6 years 4 days
Expected volatility			74.96%
Total Equity based Compensation Expense	707,000		$ 1,457,000
Unrecognized equity based compensation expense	$ 12,400,000		$ 12,400,000
Unrecognized equity based compensation expense expected period for recognition			3 years 4 months 10 days

Equity Based Compensation - Equ

Equity Based Compensation - Equity based compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity Based Compensation
Total Equity based Compensation Expense	$ 989	$ 136	$ 2,154	$ 394
Research and development expense
Equity Based Compensation
Total Equity based Compensation Expense	586	81	1,287	230
General and administrative expense
Equity Based Compensation
Total Equity based Compensation Expense	$ 403	$ 55	$ 867	$ 164

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Taxes
Provision for income taxes	$ 304,000	$ 0	$ 569,000	$ 0
Unrecognized tax benefits	$ 0		$ 0

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total Minimum Lease Payments
2019	$ 274,000		$ 274,000
2020	1,122,000		1,122,000
2021	1,175,000		1,175,000
2022	495,000		495,000
Total minimum lease payments	3,066,000		3,066,000
Rent expense	237,000	$ 223,000	684,000	$ 724,000
Sublease Income
2019	(20,000)		(20,000)
2020	(83,000)		(83,000)
Total minimum lease payments	(103,000)		(103,000)
Net Minimum Lease Payments
2019	254,000		254,000
2020	1,039,000		1,039,000
2021	1,175,000		1,175,000
2022	495,000		495,000
Total minimum lease payments	$ 2,963,000		$ 2,963,000

Option and License Agreement (D

Option and License Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Investor holding percentage	3.30%		3.30%
Research and development	$ 12,635	$ 5,767	$ 36,912	$ 15,344
Deferred revenue	18,063		18,063		$ 29,862
Revenue recognized	5,675		17,311
Accounts receivable	2,364		2,364
Collaboration and option agreement with AbbVie
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	4,600		15,300
Revenue related to research services	3,800		13,700
Deferred revenue	82,900		82,900
Performance obligations satisfied			500
Research collaboration and option agreement | Janssen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	1,500		2,700
Revenue related to research services	1,900		3,600
Accounts receivable	2,400		2,400		$ 0
Deferred revenue	$ 9,200		$ 9,200

Net Loss per Unit and Share - B

Net Loss per Unit and Share - Basic and diluted net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Loss per Unit and Share
Net loss	$ (8,864)	$ (9,433)	$ (5,200)	$ (7,077)	$ (6,231)	$ (5,179)	$ (23,497)	$ (18,487)
Weighted average common shares outstanding, basic and diluted	29,999,170						11,393,192
Weighted average common units outstanding, basic and diluted				1,011,227				1,011,227
Net loss per share, basic and diluted	$ (0.30)						$ (2.06)
Net loss per unit, basic and diluted				$ (7)				$ (18.28)

Net Loss per Unit and Share - O

Net Loss per Unit and Share - Outstanding common unit or common stock equivalents (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities	3,430,088	21,738,731	3,430,088	21,738,731
Convertible preferred units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities		21,010,407		21,010,407
Incentive units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities		721,499		721,499
Restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities	449,253		449,253
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities		6,825		6,825
Shares issuable under ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities	300,000		300,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti‑dilutive securities	2,680,835		2,680,835