Keros Therapeutics (KROS) 10-Q 3 Nov 22 2022 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2022	Oct. 27, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-39264
Entity Registrant Name	KEROS THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-1173868
Entity Address, Address Line One	99 Hayden Avenue
Entity Address, Address Line Two	Suite 120
Entity Address, Address Line Three	Building E
Entity Address, City or Town	Lexington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02421
City Area Code	617
Local Phone Number	314-6297
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	KROS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		27,543,251
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001664710

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 239,426	$ 230,042
Accounts receivable	0	18,000
Prepaid expenses and other current assets	6,449	3,398
Total current assets	245,875	251,440
Operating lease right-of-use assets	447	1,067
Property and equipment, net	1,680	1,335
Restricted cash	1,327	1,327
Other long-term asset	3,221	82
TOTAL ASSETS	252,550	255,251
CURRENT LIABILITIES:
Accounts payable	2,655	3,645
Current portion of operating lease liabilities	455	862
Accrued expenses and other current liabilities	8,415	7,339
Total current liabilities	11,525	11,846
Operating lease liabilities, net of current portion	0	231
Total liabilities	11,525	12,077
STOCKHOLDERS' EQUITY:
Common stock, par value of $0.0001 per share; 200,000,000 shares authorized as of September 30, 2022 and December 31, 2021, respectively; 26,077,204 and 23,974,834 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	2	2
Additional paid-in capital	439,739	366,927
Accumulated deficit	(198,716)	(123,755)
Total stockholders' equity	241,025	243,174
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 252,550	$ 255,251

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	26,077,204	23,974,834
Common stock, shares outstanding (in shares)	26,077,204	23,974,834

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Total revenue	$ 0	$ 0	$ 0	$ 100
OPERATING EXPENSES:
Research and development	(21,039)	(14,832)	(62,398)	(36,310)
General and administrative	(6,937)	(5,365)	(20,432)	(15,297)
Total operating expenses	(27,976)	(20,197)	(82,830)	(51,607)
LOSS FROM OPERATIONS	(27,976)	(20,197)	(82,830)	(51,507)
OTHER INCOME (EXPENSE), NET
Interest expense, net	0	(1)	(1)	(3)
Research and development incentive income	3,705	0	7,081	0
Other income (expense), net	762	(137)	789	(282)
Total other income (expense), net	4,467	(138)	7,869	(285)
Loss before income taxes	(23,509)	(20,335)	(74,961)	(51,792)
Income tax (provision) benefit	0	38	0	(12)
Net loss	(23,509)	(20,297)	(74,961)	(51,804)
Net loss attributable to common stockholders—basic	(23,509)	(20,297)	(74,961)	(51,804)
Net loss attributable to common stockholders— diluted	$ (23,509)	$ (20,297)	$ (74,961)	$ (51,804)
Net loss per share attributable to common stockholders - basic (in USD per share)	$ (0.92)	$ (0.87)	$ (3.05)	$ (2.22)
Net loss per share attributable to common stockholders - diluted (in USD per share)	$ (0.92)	$ (0.87)	$ (3.05)	$ (2.22)
Weighted-average common stock outstanding - basic (in shares)	25,549,701	23,362,237	24,538,159	23,299,720
Weighted-average common stock outstanding - diluted (in shares)	25,549,701	23,362,237	24,538,159	23,299,720
Revenue, Product and Service [Extensible Enumeration]	License	License	License	License

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED DEFICIT
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending balance (in shares)		23,192,866
Ending balance	$ 261,721	$ 2	$ 326,730	$ (65,011)
Beginning balance (in shares) at Dec. 31, 2020		23,192,866
Beginning balance at Dec. 31, 2020	261,721	$ 2	326,730	(65,011)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		78,628
Exercise of common stock options	42		42
Stock-based compensation	2,494		2,494
Net loss	(15,885)			(15,885)
Beginning balance (in shares) at Dec. 31, 2020		23,192,866
Beginning balance at Dec. 31, 2020	261,721	$ 2	326,730	(65,011)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(51,804)
Ending balance (in shares)		23,271,494
Ending balance	248,372	$ 2	329,266	(80,896)
Beginning balance (in shares) at Mar. 31, 2021		23,271,494
Beginning balance at Mar. 31, 2021	248,372	$ 2	329,266	(80,896)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		57,277
Exercise of common stock options	57		57
Stock-based compensation	2,849		2,849
Net loss	(15,622)			(15,622)
Ending balance (in shares)		23,328,771
Ending balance	235,656	$ 2	332,172	(96,518)
Beginning balance (in shares) at Jun. 30, 2021		23,328,771
Beginning balance at Jun. 30, 2021	235,656	$ 2	332,172	(96,518)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		68,022
Exercise of common stock options	35		35
Stock-based compensation	3,084		3,084
Net loss	(20,297)			(20,297)
Ending balance (in shares)		23,396,793
Ending balance	218,478	$ 2	335,291	(116,815)
Ending balance (in shares)		23,974,834
Ending balance	243,174	$ 2	366,927	(123,755)
Beginning balance (in shares) at Dec. 31, 2021		23,974,834
Beginning balance at Dec. 31, 2021	243,174	$ 2	366,927	(123,755)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		28,269
Exercise of common stock options	118		118
Stock-based compensation	4,388		4,388
Net loss	(24,186)			(24,186)
Beginning balance (in shares) at Dec. 31, 2021		23,974,834
Beginning balance at Dec. 31, 2021	$ 243,174	$ 2	366,927	(123,755)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)	154,623
Net loss	$ (74,961)
Ending balance (in shares)		24,003,103
Ending balance	223,494	$ 2	371,433	(147,941)
Beginning balance (in shares) at Mar. 31, 2022		24,003,103
Beginning balance at Mar. 31, 2022	223,494	$ 2	371,433	(147,941)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		70,854
Exercise of common stock options	502		502
Issuance of common stock, net of underwriting discounts, commissions and offering costs (in shares)		355,425
Issuance of common stock, net of underwriting discounts, commissions and offering costs	9,684		9,684
Stock-based compensation	4,794		4,794
Net loss	(27,266)			(27,266)
Ending balance (in shares)		24,429,382
Ending balance	211,208	$ 2	386,413	(175,207)
Beginning balance (in shares) at Jun. 30, 2022		24,429,382
Beginning balance at Jun. 30, 2022	211,208	$ 2	386,413	(175,207)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		55,500
Exercise of common stock options	96		96
Issuance of common stock, net of underwriting discounts, commissions and offering costs (in shares)		1,592,322
Issuance of common stock, net of underwriting discounts, commissions and offering costs	48,476		48,476
Stock-based compensation	4,754		4,754
Net loss	(23,509)			(23,509)
Ending balance (in shares)		26,077,204
Ending balance	$ 241,025	$ 2	$ 439,739	$ (198,716)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders’ Equity (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Statement of Stockholders' Equity [Abstract]
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001	$ 0.0001

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (23,509)	$ (24,186)	$ (20,297)	$ (15,885)	$ (74,961)	$ (51,804)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense					547	274
Loss on disposal of fixed asset					11	20
Stock-based compensation expense					13,936	8,427
Change in right-to-use asset					0	(709)
Non-cash lease expense					620	322
Changes in operating assets and liabilities:
Accounts receivable					18,000	0
Prepaid expenses and other current assets					(3,051)	(2,875)
Other assets					(1,574)	0
Accounts payable					(1,003)	662
Right-to-use assets and operating lease liabilities					(2,203)	397
Accrued expenses and other current liabilities					1,059	2,749
Other liabilities					0	(46)
Net cash used in operating activities					(48,619)	(42,583)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment					(890)	(865)
Net cash used in investing activities					(890)	(865)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of offering cost					58,177	0
Proceeds from exercise of stock options					716	134
Net cash provided by financing activities					58,893	134
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH					9,384	(43,314)
Cash, cash equivalents and restricted cash at beginning of period		$ 231,369		$ 265,991	231,369	265,991	$ 265,991
Cash, cash equivalents and restricted cash at end of period	240,753		222,677		240,753	222,677	231,369
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Right-of-use assets obtained in exchange for operating lease obligation					0	709
Property and equipment purchases in accounts payable					13	135
Issuance cost in accrued expenses					17	0
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	239,426		221,349		239,426	221,349	230,042
Restricted cash	1,327		1,328		1,327	1,328
Total cash, cash equivalents and restricted cash	$ 240,753		$ 222,677		$ 240,753	$ 222,677	$ 231,369

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	NATURE OF BUSINESS AND BASIS OF PRESENTATION Keros Therapeutics, Inc. (“Keros” or the “Company”) was incorporated in 2015 as a Delaware corporation. Its principal offices are in Lexington, Massachusetts. The Company is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments for patients suffering from hematological, pulmonary and cardiovascular disorders with high unmet medical need. The Company’s lead protein therapeutic product candidate, KER-050, is an engineered ligand trap comprised of a modified ligand-binding domain of the transforming growth factor-beta (“TGF-ß”) receptor known as activin receptor type IIA that is fused to the portion of the human antibody known as the Fc domain. KER-050 is being developed for the treatment of low blood cell counts (“cytopenias”), including anemia and thrombocytopenia, in patients with myelodysplastic syndromes (“MDS”) and in patients with myelofibrosis. The Company’s lead small molecule product candidate, KER-047, is designed to selectively and potently inhibit activin receptor-like kinase-2 (“ALK2”), a TGF-ß receptor. KER-047 is being developed for the treatment of functional iron deficiency which is a consequence of elevated ALK2 signaling, including the Company’s initial target, iron-refractory iron deficiency anemia (“IRIDA”). The Company’s third product candidate, KER-012, is designed to bind to and inhibit the signaling of TGF-ß ligands that stimulate smooth muscle hypertrophy and fibrosis, including activin A, activin B and myostatin (GDF8). KER-012 is being developed for the treatment of pulmonary arterial hypertension (“PAH”) and for the treatment of cardiovascular disorders associated with cardiac hypertrophy. Since its inception in 2015, the Company has devoted the majority of its resources to business planning, research and development of its product candidates, including conducting clinical trials and preclinical studies, raising capital and recruiting management and technical staff to support these operations. To date, the Company has not generated any revenue from product sales as none of its product candidates have been approved for commercialization. In May 2021, the Company filed a registration statement on Form S-3, which was automatically effective upon filing. Pursuant to this registration statement, the Company may issue up to $150.0 million in common stock in sales deemed to be an “at the market offering,” as defined by the Securities Act of 1933, as amended (“Securities Act”), and, so long as the Company qualifies as a “well-known seasoned issuer” as defined in Rule 405 of the Securities Act, an unspecified amount of shares of the Company common stock, preferred stock, debt securities and warrants. Liquidity and Capital Resources The Company’s condensed consolidated financial statements have been prepared on the basis of the Company continuing as a going concern for the next 12 months. Management believes that the Company’s existing $239.4 million in cash and cash equivalents, will allow the Company to continue its operations for at least the next 12 months. In the absence of a significant source of recurring revenue, the continued viability of the Company beyond that point is dependent on its ability to continue to raise additional capital to finance its operations. If the Company is unable to obtain additional funding, the Company may be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. The accompanying unaudited interim condensed consolidated financial statements as of September 30, 2022 and for the three and nine months ended September 30, 2022 and 2021 have been prepared by the Company in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and, pursuant to the rules and regulations of Article 10 of Regulation S-X of the Securities Act published by the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes the disclosures are adequate. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto for the year ended

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies The significant accounting policies and estimates used in preparation of the unaudited interim condensed consolidated financial statements are described in the Company’s audited consolidated financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Annual Report. Except as detailed below, there have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2022. Risks and Uncertainties As a result of the continuing global COVID-19 pandemic, the Company has implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on its employees and its business operations, including its preclinical studies and clinical trials, supply chains and third-party providers. Additionally, in response to the spread of COVID-19, the Company closed its principal executive office in March 2020, with its administrative employees continuing their work outside of the office, and limited the number of staff in any given research laboratory. In July 2021, the Company implemented a plan to reopen its principal executive office to allow employees to return on-site to the office, which is based on a phased approach that is principles-based and local in design, with a focus on continuity of preclinical studies and clinical trial activities, employee safety and optimal work environment. The Company anticipates that the COVID-19 pandemic will continue to have an impact on the development timelines for several of its preclinical and clinical programs. The extent to which the COVID-19 pandemic impacts the Company’s business, its clinical development and regulatory efforts, its corporate development objectives and the value of and market for its common stock will depend on future developments which are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, particularly in light of variant strains of the COVID-19 virus, travel restrictions, quarantines, social distancing and business closure requirements in the United States, Australia, New Zealand, Europe, South Korea and other countries and the effectiveness of actions taken globally to contain and treat the disease. The global economic slowdown, manufacturing and supply chain issues, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic could have a material adverse effect on the Company’s business, financial condition, results of operations and growth prospects. As of the date of issuance of these financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. Actual results could differ from those estimates, and any such differences may be material to the Company’s financial statements. In addition, the Company is subject to other challenges and risks specific to its business and its ability to execute on its business plan and strategy, as well as risks and uncertainties common to companies in the biopharmaceutical industry with research and development operations, including, without limitation, risks and uncertainties associated with: obtaining regulatory approval of its product candidates; delays or problems in obtaining clinical supply, loss of single source suppliers or failure to comply with manufacturing regulations; product development and the inherent uncertainty of clinical success; the challenges of protecting and enhancing its intellectual property rights; the challenges of complying with applicable regulatory requirements; and identifying, acquiring or in-licensing additional products or product candidates. In addition, to the extent the ongoing COVID-19 pandemic adversely affects the Company’s business and results of operations, it may also have the effect of heightening many of the other risks and uncertainties discussed above.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): DESCRIPTION SEPTEMBER 30, 2022 QUOTED PRICES ACTIVE MARKETS FOR IDENTICAL ASSETS SIGNIFICANT OTHER OBSERVABLE INPUTS SIGNIFICANT OTHER OBSERVABLE INPUTS Assets Money market funds $ 234,817 $ 234,817 $ — $ — Total financial assets $ 234,817 $ 234,817 $ — $ — DESCRIPTION DECEMBER 31, 2021 QUOTED PRICES ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 3) Assets Money market funds $ 230,042 $ 230,042 $ — $ — Total financial assets $ 230,042 $ 230,042 $ — $ —

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Prepaid service contracts $ 3,045 $ 1,613 Income tax credit receivable — 30 Prepaid sales tax 62 255 Prepaid rent 124 — R&D payroll tax credit 146 167 Prepaid subscription 588 130 Prepaid insurance 1,739 993 Other 745 210 Total prepaid expenses and other current assets $ 6,449 $ 3,398

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Accrued external R&D costs $ 1,954 $ 861 Accrued external manufacturing costs 1,729 3,259 Accrued compensation and benefits 3,873 2,373 Accrued tax 37 110 Accrued professional fees 535 532 Other 287 204 Total accrued expenses and other current liabilities $ 8,415 $ 7,339

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Common Stock	COMMON STOCK As of September 30, 2022, the Company’s amended and restated certificate of incorporation authorized the Company to issue 200,000,000 shares of common stock at a par value of $0.0001 per share. On May 3, 2021, the Company entered into a Sales Agreement (the “ATM Sales Agreement”) with SVB Leerink LLC (“SVB Leerink”), as agent, pursuant to which the Company may offer and sell, from time to time, shares of its common stock having an aggregate offering price of up to $150.0 million from time to time through SVB Leerink (the “ATM Offering”). For the year ended December 31, 2021, the Company raised gross proceeds of $28.6 million pursuant to the ATM Offering through the sale of 520,000 shares of common stock at a weighted average price of $55.00 per share. The net proceeds from the ATM Offering were approximately $28.1 million after deducting sales agent commissions of $0.4 million and offering expenses of $0.1 million. As of December 31, 2021, the Company was eligible to offer and sell, from time to time, shares of its common stock for an aggregate offering amount of up to the remaining $121.4 million available under the ATM Offering. During the nine months ended September 30, 2022, the Company raised gross proceeds of $59.1 million pursuant to the ATM Offering through the sale of 1,947,747 shares of common stock at a weighted average price of $30.35 per share. The net proceeds from the ATM Offering were approximately $58.2 million after deducting sales agent commissions and offering expense of $0.9 million. As of September 30, 2022, the Company was eligible to offer and sell, from time to time, shares of its common stock for an aggregate offering amount of up to the remaining $62.3 million available under the ATM Offering. As of September 30, 2022 and December 31, 2021, the Company had an aggregate of the following options to purchase shares of common stock: SEPTEMBER 30, DECEMBER 31, Options to purchase common stock 3,483,918 2,810,684 The Company’s potentially dilutive securities have been excluded from the computation of diluted net loss per share, as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION 2017 Stock Incentive Plan The Board adopted the 2017 Stock Incentive Plan (the "2017 Plan") in February 2017, and the stockholders approved the 2017 Plan in March 2017. The 2017 Plan was most recently amended in March 2020. As of September 30, 2022, there was an aggregate of 585,165 shares of common stock issuable upon the exercise of outstanding options under the 2017 Plan. Any options or awards outstanding under the 2017 Plan remain outstanding and effective. 2020 Equity Incentive Plan In April 2020, the 2020 Equity Incentive Plan (the "2020 Plan") became effective, and, as a result, no further awards will be made under the 2017 Plan. The 2020 Plan provides for the grant of stock options qualifying as incentive stock options ("ISOs"), to employees and for the grant of nonstatutory stock options ("NSOs"), restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of stock compensation to employees, consultants and directors. The 2020 Plan also provides for the grant of performance cash awards to employees, consultants and directors. Any previously granted awards under the 2017 Plan will remain outstanding in accordance with their respective terms. Under the 2020 Plan, there is an annual increase on January 1 of each year from January 1, 2021 continuing through January 1, 2030, by 4.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Board. On January 1, 2022, the Company increased the number of shares available for future grant under the 2020 Plan by 958,993 shares. As of September 30, 2022, there was an aggregate of 2,898,753 shares of common stock issuable upon the exercise of outstanding options under the 2020 Plan. Additionally, there were an aggregate of 1,025,240 shares reserved for future issuance under the 2020 Plan, including shares forfeited from the 2017 Plan. Stock Options A summary of option activity during the nine months ended September 30, 2022 is as follows (in thousands except share and per share data): NUMBER OF OPTIONS WEIGHTED-AVERAGE EXERCISE PRICE Outstanding as of December 31, 2021 2,810,684 $ 24.62 Granted 1,003,658 44.02 Exercised (154,623) 4.62 Cancelled or Forfeited (166,521) 40.02 Expired (9,280) $ (58.30) Outstanding as of September 30, 2022 3,483,918 $ 30.27 Options exercisable as of December 31, 2021 1,223,019 $ 10.48 Options exercisable as of September 30, 2022 1,593,416 $ 18.37 The weighted-average grant date fair value price per share of options granted during the nine months ended September 30, 2022 and 2021 was $31.42 and $42.92, respectively. As of September 30, 2022, there was $48.0 million of unrecognized stock-based compensation expense related to unvested stock options. The unrecognized stock-based compensation expense is estimated to be recognized over a period of 2.63 years. The total fair value of options vested during the nine months ended September 30, 2022 was $12.7 million. The aggregate intrinsic value of the stock options outstanding and stock options exercisable was $47.9 million and $36.3 million for the nine months ended September 30, 2022, respectively. Stock-Based Compensation Expense Total stock-based compensation expense recorded for employees, directors and non-employees during the three and nine months ended September 30, 2022 and 2021 was as follows (in thousands): THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Research and development $ 2,132 $ 1,018 $ 6,095 $ 3,032 General and administrative 2,622 2,066 7,841 5,395 Total stock-based compensation expense $ 4,754 $ 3,084 $ 13,936 $ 8,427

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXESOn March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) was signed into law in the United States. The CARES Act provides numerous tax provisions and other stimulus measures, including temporary changes regarding the prior and future utilization of net operating losses and technical corrections from prior tax legislation for tax depreciation of certain qualified improvement property. The Company evaluated the provisions of the CARES Act and as a result, received approximately $0.2 million in February 2021 related to the carryback of our 2019 net operating loss to claim a refund for prior federal tax liabilities.

Loss Per Share

Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Loss Per Share	LOSS PER SHARE The Company’s potentially dilutive securities, which includes stock options, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following from the computation of diluted net loss per share attributable to common stockholders at September 30, 2022 and 2021 because including them would have had an anti-dilutive effect: SEPTEMBER 30, SEPTEMBER 30, Options to purchase common stock 3,483,918 2,724,800

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	REVENUE FROM CONTRACTS WITH CUSTOMERS Neurona Therapeutics, Inc. License Agreement On June 22, 2021, the Company entered into a license agreement (the "Neurona Agreement") with Neurona Therapeutics, Inc. (“Neurona”). Under the Neurona Agreement, the Company granted Neurona a non-exclusive license to use LDN-193189, an early-stage research compound, which the Company licenses from a third party, solely as a reagent in connection with the manufacturing of diagnostic and/or therapeutic products to make, have made, use, import, offer for sale and sell products and services arising therefrom, and to make, have made, acquire, transfer, import and export the compound for such use. The license excludes Neurona from any rights to use, sell or distribute the compound for any therapeutic or diagnostic purpose. Unless terminated by either party for breach of contract or insolvency, the Neurona Agreement, which commenced on the execution date, will continue in perpetuity until the last patent expires. Under the Neurona Agreement, the Company was paid a one-time, upfront license payment of $0.1 million from Neurona as of September 30, 2021. In accordance with the Company's ASC 606 assessment, Neurona is considered to be a customer. The Company identified a single performance obligation, the non-exclusive license, that was satisfied on the date of the execution of the Neurona Agreement when control of the license was transferred. The Company determined that the upfront license fee of $0.1 million constitutes the entire transaction price and does not require further allocation as there was only one performance obligation. The Company determined that the $0.1 million represented the point at which the licensee was able to use and benefit from the license and recognized revenue from upfront license fees when the license was transferred to Neurona upon execution of the Neurona Agreement. The Company recognized the upfront fee as revenue on its consolidated statement of operations for the nine months ended September 30, 2021. Hansoh License Agreement On December 12, 2021, the Company entered into a license agreement (the “Hansoh Agreement”) with Hansoh (Shanghai) Healthtech Co., Ltd. ("Hansoh"). Under the Hansoh Agreement, the Company granted to Hansoh the exclusive right to develop, manufacture and commercialize KER-050 and licensed products containing KER-050 within the territories of mainland China, Hong Kong and Macau (the “Territory”). In connection with the Hansoh Agreement, Hansoh will purchase clinical trial supply of KER-050 from the Company, and the parties will also negotiate in good faith to enter into an agreement for commercial supply prior to any anticipated commercialization in the Territory. In addition, Hansoh will use commercially reasonable efforts to develop, obtain regulatory approval for, and commercialize licensed products in any region in the Territory. Pursuant to the Hansoh Agreement, the Company received a one-time, net $18.0 million upfront license payment and will also be eligible to receive up to an aggregate of (i) $26.5 million upon the achievement of specified development milestones and (ii) $144.0 million upon the achievement of specified net sales thresholds for all licensed products in the Territory. If a licensed product is approved for marketing in the Territory, the Company will be entitled to receive royalty payments based on a tiered percentage of annual net sales in each region within the Territory, with such percentage ranging from the low double digit to high teens, subject to specified potential royalty reductions. Hansoh’s obligation to pay royalties for a given licensed product in a given region in the Territory will begin on the date of the first commercial sale for such licensed product in such region and continue until the latest of (i) 10 years from the date of the first commercial sale for such licensed product in such region, (ii) the expiration of the last valid claim of certain licensed patents or joint patents, and (iii) expiration of regulatory exclusivity in such region. During the royalty term, neither party will directly nor indirectly commercialize a competing product in the Territory. The Hansoh Agreement will continue in force on a region-by-region basis until the expiration of the royalty term. Hansoh may terminate the Agreement in its entirety for convenience, with notice. The Company may terminate the Hansoh Agreement in its entirety for a patent challenge brought by Hansoh or its affiliates or their sublicensees. Either party may terminate the Hansoh Agreement in its entirety (i) if the other party materially breaches the Hansoh Agreement and fails to cure such breach or (ii) upon the bankruptcy of the other party. The Company evaluated the Hansoh Agreement and concluded that it was subject to ASC 606, as the Company viewed the Hansoh Agreement as a contract with a customer. As such, the Company assessed the terms of the Hansoh Agreement and identified a single performance obligation for the Company to provide Hansoh an exclusive license to develop, manufacture and commercialize KER-050 and licensed products containing KER-050 in the Territory, including the underlying know-how related to such licenses. All other promised goods/services were deemed immaterial in the context of the Hansoh Agreement. Under the Hansoh Agreement, the Company was paid a one-time, upfront license payment of net $18.0 million from Hansoh during the nine months ended September 30, 2022. The Company recognized the gross upfront fee of $20.0 million as revenue and $2.0 million in withholding tax on its consolidated statement of operations in the fourth quarter for the year ended December 31, 2021, and a receivable, net of withholding tax on its consolidated balance sheet as of December 31, 2021. The Company will recognize development milestone payments as revenue at the point in time when it is determined that it is probable such milestones will be achieved as all performance obligations will have been satisfied at the point which a milestone might occur (i.e., Hansoh will have assumed all responsibility for the activities under the Hansoh Agreement). The Company will recognize royalty payments and commercial milestone payments as the associated sales of licensed products are recorded by Hansoh, as they predominantly relate to the license granted with the Hansoh Agreement. No milestones have been received as of September 30, 2022.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Significant Accounting Policies	The significant accounting policies and estimates used in preparation of the unaudited interim condensed consolidated financial statements are described in the Company’s audited consolidated financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Annual Report. Except as detailed below, there have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2022.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): DESCRIPTION SEPTEMBER 30, 2022 QUOTED PRICES ACTIVE MARKETS FOR IDENTICAL ASSETS SIGNIFICANT OTHER OBSERVABLE INPUTS SIGNIFICANT OTHER OBSERVABLE INPUTS Assets Money market funds $ 234,817 $ 234,817 $ — $ — Total financial assets $ 234,817 $ 234,817 $ — $ — DESCRIPTION DECEMBER 31, 2021 QUOTED PRICES ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1) SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 3) Assets Money market funds $ 230,042 $ 230,042 $ — $ — Total financial assets $ 230,042 $ 230,042 $ — $ —

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Prepaid service contracts $ 3,045 $ 1,613 Income tax credit receivable — 30 Prepaid sales tax 62 255 Prepaid rent 124 — R&D payroll tax credit 146 167 Prepaid subscription 588 130 Prepaid insurance 1,739 993 Other 745 210 Total prepaid expenses and other current assets $ 6,449 $ 3,398

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Accrued external R&D costs $ 1,954 $ 861 Accrued external manufacturing costs 1,729 3,259 Accrued compensation and benefits 3,873 2,373 Accrued tax 37 110 Accrued professional fees 535 532 Other 287 204 Total accrued expenses and other current liabilities $ 8,415 $ 7,339

Common Stock (Tables)

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Summary of Preferred Stock	As of September 30, 2022 and December 31, 2021, the Company had an aggregate of the following options to purchase shares of common stock: SEPTEMBER 30, DECEMBER 31, Options to purchase common stock 3,483,918 2,810,684

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Option Activity	A summary of option activity during the nine months ended September 30, 2022 is as follows (in thousands except share and per share data): NUMBER OF OPTIONS WEIGHTED-AVERAGE EXERCISE PRICE Outstanding as of December 31, 2021 2,810,684 $ 24.62 Granted 1,003,658 44.02 Exercised (154,623) 4.62 Cancelled or Forfeited (166,521) 40.02 Expired (9,280) $ (58.30) Outstanding as of September 30, 2022 3,483,918 $ 30.27 Options exercisable as of December 31, 2021 1,223,019 $ 10.48 Options exercisable as of September 30, 2022 1,593,416 $ 18.37
Schedule of Stock-based Compensation Expense	Total stock-based compensation expense recorded for employees, directors and non-employees during the three and nine months ended September 30, 2022 and 2021 was as follows (in thousands): THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Research and development $ 2,132 $ 1,018 $ 6,095 $ 3,032 General and administrative 2,622 2,066 7,841 5,395 Total stock-based compensation expense $ 4,754 $ 3,084 $ 13,936 $ 8,427

Loss Per Share (Tables)

Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded From Computation of Diluted Net Loss Per Share	The Company excluded the following from the computation of diluted net loss per share attributable to common stockholders at September 30, 2022 and 2021 because including them would have had an anti-dilutive effect: SEPTEMBER 30, SEPTEMBER 30, Options to purchase common stock 3,483,918 2,724,800

Nature of Business and Basis _2

Nature of Business and Basis of Presentation (Details) - USD ($)		1 Months Ended
	May 03, 2021	May 31, 2021	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Class of Stock [Line Items]
Cash and cash equivalents			$ 239,426,000	$ 230,042,000	$ 221,349,000
At the Market Offering
Class of Stock [Line Items]
Stock sales agreement, maximum amount authorized to be issued	$ 150,000,000	$ 150,000,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets
Money market funds	$ 234,817	$ 230,042
Total financial assets	234,817	230,042
QUOTED PRICES ACTIVE MARKETS FOR IDENTICAL ASSETS (LEVEL 1)
Assets
Money market funds	234,817	230,042
Total financial assets	234,817	230,042
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets
Money market funds	0	0
Total financial assets	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 3)
Assets
Money market funds	0	0
Total financial assets	$ 0	$ 0

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid service contracts	$ 3,045	$ 1,613
Income tax credit receivable	0	30
Prepaid sales tax	62	255
Prepaid rent	124	0
R&D payroll tax credit	146	167
Prepaid subscription	588	130
Prepaid insurance	1,739	993
Other	745	210
Total prepaid expenses and other current assets	$ 6,449	$ 3,398

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued external R&D costs	$ 1,954	$ 861
Accrued external manufacturing costs	1,729	3,259
Accrued compensation and benefits	3,873	2,373
Accrued tax	37	110
Accrued professional fees	535	532
Other	287	204
Total accrued expenses and other current liabilities	$ 8,415	$ 7,339

Common Stock - Narrative (Detai

Common Stock - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 03, 2021	May 31, 2021	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			200,000,000		200,000,000		200,000,000
Common stock, par value (in USD per share)			$ 0.0001		$ 0.0001	$ 0.0001	$ 0.0001
Proceeds from issuance of common stock, net of offering cost					$ 58,177,000	$ 0
At the Market Offering
Class of Stock [Line Items]
Stock sales agreement, maximum amount authorized to be issued	$ 150,000,000	$ 150,000,000
At the Market Offering | Common stock
Class of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)					1,947,747		520,000
Sale of stock, price per share (in USD per share)			$ 30.35		$ 30.35		$ 55
Proceeds from issuance of common stock, net of offering cost					$ 58,200,000		$ 28,100,000
Proceeds from initial public offering, net of discounts and offering costs					59,100,000		28,600,000
Sales agent commissions							400,000
Issuance costs			$ 796,000	$ 153,000	900,000		100,000
Sale of stock, remaining authorized amount			$ 62,300,000		$ 62,300,000		$ 121,400,000

Common Stock - Summary of Commo

Common Stock - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2022	Dec. 31, 2021
Options to purchase common stock
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	3,483,918	2,810,684

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		9 Months Ended
	Jan. 01, 2022	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period (in shares)		1,003,658
Weighted-average grant date fair value of options granted during the period (in dollars per share)		$ 31.42	$ 42.92
Unrecognized stock-based compensation expense related to unvested stock options		$ 48
Total fair value of options vested during period		12.7
Options outstanding, value		47.9
Options exercisable, value		$ 36.3
Employee Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested award, period for recognition		2 years 7 months 17 days
2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		585,165
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual percentage increase in shares authorized		4%
Number of additional shares authorized (in shares)	958,993
Options granted in period (in shares)		2,898,753
Number of shares available for future grants (in shares)		1,025,240

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares shares	Dec. 31, 2021 $ / shares shares
NUMBER OF OPTIONS
Outstanding as of beginning of period (in shares) | shares	2,810,684
Granted (in shares) | shares	1,003,658
Exercised (in shares) | shares	(154,623)
Cancelled & Forfeited (in shares) | shares	(166,521)
Expired (in shares) | shares	(9,280)
Outstanding as of end of period (in shares) | shares	3,483,918
Exercisable (in shares) | shares	1,593,416	1,223,019
WEIGHTED-AVERAGE EXERCISE PRICE
Outstanding as of beginning of period (in USD per share) | $ / shares	$ 24.62
Granted (in USD per share) | $ / shares	44.02
Exercised (in USD per share) | $ / shares	4.62
Cancelled & Forfeited (in USD per share) | $ / shares	40.02
Expired (in USD per share) | $ / shares	(58.30)
Outstanding as of end of period (in USD per share) | $ / shares	30.27
Exercisable (in USD per share) | $ / shares	$ 18.37	$ 10.48

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 4,754	$ 3,084	$ 13,936	$ 8,427
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	2,132	1,018	6,095	3,032
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 2,622	$ 2,066	$ 7,841	$ 5,395

Income Taxes (Details)

Income Taxes (Details) $ in Millions	1 Months Ended
	Feb. 28, 2021 USD ($)
Income Tax Disclosure [Abstract]
Proceeds from income tax refunds	$ 0.2

Loss Per Share (Details)

Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,483,918	2,724,800

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Dec. 31, 2021	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Research collaboration revenue		$ 0		$ 0	$ 0	$ 100
The General Hospital Corporation | License Agreement
Disaggregation of Revenue [Line Items]
Expiration Period	10 years
License | Neurona Therapeutics Inc
Disaggregation of Revenue [Line Items]
Research collaboration revenue						$ 100
License | Hansoh Shanghai Healthtech Co Ltd
Disaggregation of Revenue [Line Items]
Research collaboration revenue			$ 20,000		18,000
Revenue, remaining performance obligation, development milestones, variable consideration		26,500			26,500
Revenue, remaining performance obligation, sales milestones, variable consideration amount		$ 144,000			$ 144,000
Withholding taxes from upfront fee			$ 2,000