Passage Bio (PASG) 10-Q10 Nov 222022 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2022	Nov. 04, 2022
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-39231
Entity Registrant Name	PASSAGE BIO, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-2729751
Entity Address, Address Line One	One Commerce Square
Entity Address, Address Line Two	2005 Market Street, 39th Floor
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19103
City Area Code	267
Local Phone Number	866-0311
Title of 12(b) Security	Common Stock
Trading Symbol	PASG
Security Exchange Name	NASDAQ
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		54,553,263
Entity Central Index Key	0001787297
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 62,568	$ 128,965
Marketable securities	151,190	186,808
Prepaid expenses and other current assets	1,509	1,726
Prepaid research and development	7,257	7,567
Total current assets	222,524	325,066
Property and equipment, net	22,918	23,806
Right of use assets - operating leases	19,890
Other assets	4,720	6,204
Total assets	270,052	355,076
Current liabilities:
Accounts payable	4,506	9,448
Accrued expenses and other current liabilities	13,861	20,050
Operating lease liabilities	3,252
Total current liabilities	21,619	29,498
Operating lease liabilities - noncurrent	24,037
Deferred rent		6,921
Total liabilities	45,656	36,419
Commitments and Contingencies (note 9)
Stockholders' equity:
Common stock, $0.0001 par value: 300,000,000 shares authorized; 54,546,596 shares issued and outstanding at September 30, 2022 and 54,244,996 shares issued and outstanding at December 31, 2021	5	5
Additional paidin capital	691,194	675,346
Accumulated other comprehensive income (loss)	(1,468)	(413)
Accumulated deficit	(465,335)	(356,281)
Total stockholders' equity	224,396	318,657
Total liabilities and stockholders' equity	$ 270,052	$ 355,076

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Balance Sheets
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	54,546,596	54,244,996
Common stock, shares outstanding	54,546,596	54,244,996

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating expenses:
Research and development	$ 15,362	$ 26,623	$ 68,396	$ 84,705
Acquired inprocess research and development	1,500	5,500	3,000	7,000
General and administrative	10,664	14,978	38,754	42,864
Loss from operations	(27,526)	(47,101)	(110,150)	(134,569)
Interest income, net	825	186	1,096	337
Net loss	$ (26,701)	$ (46,915)	$ (109,054)	$ (134,232)
Per share information:
Net loss per share of common stock, basic	$ (0.49)	$ (0.87)	$ (2.01)	$ (2.53)
Net loss per share of common stock, diluted	$ (0.49)	$ (0.87)	$ (2.01)	$ (2.53)
Weighted average common shares outstanding, basic	54,473,945	53,995,560	54,379,397	53,080,645
Weighted average common shares outstanding, diluted	54,473,945	53,995,560	54,379,397	53,080,645
Comprehensive loss:
Net loss	$ (26,701)	$ (46,915)	$ (109,054)	$ (134,232)
Unrealized gain (loss) on marketable securities	110	14	(1,055)	45
Comprehensive loss	$ (26,591)	$ (46,901)	$ (110,109)	$ (134,187)

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit	Total
Balance at Beginning of period at Dec. 31, 2020	$ 4	$ 475,617	$ (12)	$ (170,895)	$ 304,714
Balance at Beginning of period (in shares) at Dec. 31, 2020	45,614,807
Stockholders' equity
Vesting of early exercise option awards		45			45
Vesting of early exercise option awards (in shares)	211,865
Exercise of stock options and vesting of restricted stock units		229			229
Exercise of stock options and vesting of restricted stock units (in shares)	101,479
Issuance of shares in connection with employee stock purchase plan		505			505
Issuance of shares in connection with employee stock purchase plan (in shares)	38,348
Sale of common stock, net of issuance costs	$ 1	165,804			165,805
Sale of common stock, net of issuance costs (in shares)	8,050,000
Unrealized gain (loss) on marketable securities			45		45
Share-based compensation expense		25,116			25,116
Net loss				(134,232)	(134,232)
Balance at end of period at Sep. 30, 2021	$ 5	667,316	33	(305,127)	362,227
Balance at end of period (in shares) at Sep. 30, 2021	54,016,499
Balance at Beginning of period at Jun. 30, 2021	$ 5	660,457	19	(258,212)	402,269
Balance at Beginning of period (in shares) at Jun. 30, 2021	53,956,380
Stockholders' equity
Vesting of early exercise option awards (in shares)	19,373
Exercise of stock options and vesting of restricted stock units		44			44
Exercise of stock options and vesting of restricted stock units (in shares)	40,746
Unrealized gain (loss) on marketable securities			14		14
Share-based compensation expense		6,815			6,815
Net loss				(46,915)	(46,915)
Balance at end of period at Sep. 30, 2021	$ 5	667,316	33	(305,127)	362,227
Balance at end of period (in shares) at Sep. 30, 2021	54,016,499
Balance at Beginning of period at Dec. 31, 2021	$ 5	675,346	(413)	(356,281)	318,657
Balance at Beginning of period (in shares) at Dec. 31, 2021	54,244,996
Stockholders' equity
Exercise of stock options and vesting of restricted stock units		128			128
Exercise of stock options and vesting of restricted stock units (in shares)	146,056
Issuance of shares in connection with employee stock purchase plan		243			243
Issuance of shares in connection with employee stock purchase plan (in shares)	155,544
Unrealized gain (loss) on marketable securities			(1,055)		(1,055)
Share-based compensation expense		15,477			15,477
Net loss				(109,054)	(109,054)
Balance at end of period at Sep. 30, 2022	$ 5	691,194	(1,468)	(465,335)	224,396
Balance at end of period (in shares) at Sep. 30, 2022	54,546,596
Balance at Beginning of period at Jun. 30, 2022	$ 5	688,253	(1,578)	(438,634)	248,046
Balance at Beginning of period (in shares) at Jun. 30, 2022	54,463,235
Stockholders' equity
Exercise of stock options and vesting of restricted stock units		79			79
Exercise of stock options and vesting of restricted stock units (in shares)	83,361
Unrealized gain (loss) on marketable securities			110		110
Share-based compensation expense		2,862			2,862
Net loss				(26,701)	(26,701)
Balance at end of period at Sep. 30, 2022	$ 5	$ 691,194	$ (1,468)	$ (465,335)	$ 224,396
Balance at end of period (in shares) at Sep. 30, 2022	54,546,596

Statements of Stockholders' E_2

Statements of Stockholders' Equity (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Statements of Stockholders' Equity
Issuance cost	$ 669

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Cash flows used in operating activities:
Net loss	$ (109,054)	$ (134,232)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired inprocess research and development	3,000	7,000
Depreciation and amortization	2,733	874
Sharebased compensation	15,477	25,116
Amortization of premium and discount on marketable securities, net	1,206	2,235
Deferred rent		1,618
Changes in operating assets and liabilities:
Prepaid expenses and other current assets, and other assets	1,701	(66)
Prepaid research and development	310	2,026
Right of use assets and operating lease liabilities	478
Accounts payable	(4,979)	2,085
Accrued expenses and other current liabilities	(5,061)	(2,760)
Net cash used in operating activities	(94,189)	(96,104)
Cash flows provided by (used in) investing activities:
Purchases of marketable securities	(116,304)	(169,860)
Sales or maturities of marketable securities	149,661	145,974
Purchases of technology licenses	(3,000)	(7,500)
Purchases of property and equipment	(1,800)	(10,823)
Net cash provided by (used in) investing activities	28,557	(42,209)
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock, net of offering costs		165,805
Payment of offering costs		(338)
Proceeds from the exercise of stock options	128	229
Proceeds from the issuance of common stock under employee stock purchase plan	243	505
Payments for insurance premium financing	(1,136)
Net cash provided by (used in) financing activities	(765)	166,201
Net increase (decrease) in cash and cash equivalents	(66,397)	27,888
Cash and cash equivalents at beginning of year	128,965	135,002
Cash and cash equivalents at end of period	62,568	162,890
Supplemental disclosure of noncash investing and financing activities:
Unrealized gain (loss) on marketable securities	(1,055)	45
Property and equipment in accounts payable and accrued expenses and other current liabilities	45	2,254
Property and equipment in deferred rent		2,769
Vesting of early exercise option awards		$ 45
Right of use assets recognized upon the adoption of Topic 842	(20,375)
Operating lease liabilities recognized upon the adoption of Topic 842	$ 27,296

Nature of Operations

Nature of Operations	9 Months Ended
Nature of Operations	Sep. 30, 2022
Nature of Operations
Nature of Operations	1. Nature of Operations Passage Bio, Inc., or the Company, a Delaware corporation incorporated in July 2017, is a clinical stage genetic medicines company focused on developing transformative therapies for central nervous system, or CNS disorders, with limited or no approved treatment options. The Company has a strategic research collaboration with the Trustees of the University of Pennsylvania’s, or Penn, Gene Therapy Program, or GTP, that provides the Company with access to one of the premier research institutions in the world for the discovery and preclinical development of genetic medicine product candidates, and exclusive rights to certain CNS indications. Under this collaboration, GTP conducts discovery and preclinical activities enabling Investigational New Drug, or IND, applications and the Company conducts all clinical development, manufacturing, regulatory strategy, and commercialization activities under the agreement. The Company also has a collaboration agreement and a development services and clinical supply agreement with Catalent Maryland, Inc., or Catalent,

Risks and Liquidity

Risks and Liquidity	9 Months Ended
Risks and Liquidity	Sep. 30, 2022
Risks and Liquidity
Risks and Liquidity	2. Risks and Liquidity The Company has incurred recurring losses and negative cash flows from operations since inception and had an accumulated deficit of $465.3 million as of September 30, 2022. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidates currently in development. Substantial additional capital will be needed by the Company to fund its operations and to develop its product candidates. In January 2021, the Company closed a follow-on public offering in which the Company issued and sold 8,050,000 shares of its common stock at a public offering price of $22.00 per share for net proceeds of $165.8 million after deducting underwriting discounts, commissions and other offering expenses. The Company’s operations have consisted primarily of organizing the Company, securing financing, developing licensed technology, performing research, and conducting preclinical studies and clinical trials. The Company faces risks associated with early-stage biotechnology companies whose product candidates are in development. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing, establishing manufacturing capacity and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital for the Company to complete its research and development, achieve its research and development objectives, defend its intellectual property rights, and recruit and retain skilled personnel and key members of management. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. The Company plans to seek additional funding through public or private equity offerings, debt financings, other collaborations, strategic alliances and licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into strategic alliances or other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding or prospects of funding are unfavorable, the Company could be required to further delay, reduce or eliminate research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect its business prospects. In March and November 2022, the Company announced workforce reductions and plans to prioritize research and development programs to reduce operating expenses and to extend its cash runway. In accordance with Accounting Standards Update, or ASU, No. 2014-15 , Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern its forecasted operating expenses and capital expenditure requirements for at least the next twelve months from the issuance date of these financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2022
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies The Company’s complete summary of significant accounting policies can be found in “Note 3. Summary of Significant Accounting Policies” in the audited financial statements included in the Company’s Annual Report filed on Form 10-K for the year ended December 31, 2021. Basis of Presentation The accompanying unaudited financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Updates promulgated by the Financial Accounting Standards Board, or FASB. Interim Financial Statements The accompanying unaudited interim financial statements have been prepared from the books and records of the Company in accordance with GAAP for interim financial information and Rule 10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission, or SEC, which permits reduced disclosures for interim periods. All adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the accompanying balance sheets, statements of operations, stockholders’ equity, and cash flows have been made. Although these interim financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows are not necessarily indicative of the results that may be expected for the full year. Unaudited interim financial statements and footnotes should be read in conjunction with the audited financial statements and footnotes included in the Company’s 2021 Annual Report filed on Form 10-K. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are periodically reviewed and the effects of the revisions are reflected in the accompanying financial statements in the period they are determined to be necessary. Fair Value of Financial Instruments Management believes that the carrying amounts of the Company’s financial instruments, including cash equivalents, prepaid expenses, and accounts payable, approximate fair value due to the short-term nature of those instruments. Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash, cash equivalents, and marketable securities. Cash and cash equivalents The Company considers all highly-liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash equivalents as of September 30, 2022 consisted of money market funds, certificates of deposits, corporate debt securities and commercial paper. Cash consists of cash deposits at banking institutions. Marketable securities The Company classifies its marketable securities as available-for-sale, which include commercial paper, certificates of deposit, corporate debt securities and United States, or U.S., government debt securities with original maturities of greater than three months. These securities are carried at fair market value, with unrealized gains and losses reported in comprehensive loss and accumulated other comprehensive income (loss) within stockholders’ equity. Gains or losses on marketable securities sold are recognized on the specific identification method. Share-based compensation The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. Estimating the fair value of share-based awards requires the input of subjective assumptions, including, for stock options, stock price volatility. The Company accounts for forfeitures for stock option awards as they occur. The Company uses the Black-Scholes option pricing model to value its stock option awards. The assumptions used in estimating the fair value of share-based awards represent management's estimate and involve inherent uncertainties and the application of management's judgment. As a result, if factors change and management uses different assumptions, share-based compensation expense could be materially different for future awards. The expected term of the stock options is estimated using the "simplified method," as the Company has limited historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses a composite of comparable public company data as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option. Net Loss Per Share Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as stock options, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: Nine Months Ended 2022 2021 Stock options 11,738,877 9,581,659 Unvested restricted stock units 409,500 238,333 Employee stock purchase plan 62,488 49,528 12,210,865 9,869,520 Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “ Leases” Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, “ Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments ”, or ASU 2016-13, which replaces the incurred loss impairment methodology under current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 was subsequently updated by ASU No. 2019-04, “ Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ”, to clarify that entities should include recoveries when estimating the allowance for credit losses. This guidance is effective for the Company for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022 and must be adopted using a modified retrospective approach, with certain exceptions. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures and does not expect a material impact to financial statements or disclosures .

Cash, cash equivalents and mark

Cash, cash equivalents and marketable securities	9 Months Ended
Cash, cash equivalents and marketable securities	Sep. 30, 2022
Cash, cash equivalents and marketable securities
Cash, cash equivalents and marketable securities	4. Cash, cash equivalents and marketable securities The following table provides details regarding the Company’s portfolio of cash and cash equivalents: Cost or (in thousands) Amortized cost Unrealized gains Unrealized losses Fair value September 30, 2022: Cash accounts in banking institutions $ 25,453 $ - $ - $ 25,453 Money market funds 15,721 - - 15,721 Certificates of deposit 7,032 - (2) 7,030 Corporate debt securities 554 - (1) 553 Commercial paper 13,817 - (6) 13,811 Total $ 62,576 $ - $ (9) $ 62,568 December 31, 2021 Cash accounts in banking institutions $ 44,549 $ - $ - $ 44,549 Money market funds 84,416 - - 84,416 Total $ 128,965 $ - $ - $ 128,965 The following table provides details regarding the Company’s portfolio of marketable securities: (in thousands) Amortized cost Unrealized gains Unrealized losses Fair value September 30, 2022: Certificates of deposit $ 22,012 $ 2 $ (96) $ 21,918 Commercial paper 49,451 1 (118) 49,334 Corporate debt securities 79,188 - (1,198) 77,990 U.S. government securities 1,998 - (50) 1,948 Total $ 152,649 $ 3 $ (1,462) $ 151,190 December 31, 2021 Certificates of deposit $ 5,296 $ - $ - $ 5,296 Commercial paper 26,503 4 (4) 26,503 Corporate debt securities 145,577 10 (418) 145,169 U.S. government securities 1,996 - (8) 1,988 Non-U.S. government securities 7,849 4 (1) 7,852 Total $ 187,221 $ 18 $ (431) $ 186,808

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
Fair Value of Financial Instruments	Sep. 30, 2022
Fair Value of Financial Instruments
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The carrying amounts of certain of the Company’s financial instruments, including prepaid expense and accounts payable are shown at cost, which approximates fair value due to the short-term nature of these instruments. The Company follows the provisions of FASB ASC Topic 820, Fair Value Measurement ● Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. ● Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liabilities. ● Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). The following fair value hierarchy table presents information about the Company’s assets measured at fair value on a recurring basis. Included within cash and cash equivalents on the balance sheet, but excluded from the fair value hierarchy table, are cash deposits held at financial institutions: Fair value measurement at reporting date using Quoted prices in active Significant markets for other Significant identical observable unobservable assets inputs inputs (in thousands) (Level 1) (Level 2) (Level 3) September 30, 2022: Assets Cash and cash equivalents: Certificates of deposit $ - $ 7,030 $ - Money market funds 15,721 - $ - Commercial paper - 13,811 - Corporate debt securities - 553 - Total cash and cash equivalents 15,721 21,394 - Marketable securities: Certificates of deposit - 21,918 - Commercial paper - 49,334 - Corporate debt securities - 77,990 - U.S. government securities - 1,948 - Total marketable securities - 151,190 - Total financial assets $ 15,721 $ 172,584 $ - December 31, 2021 Assets Cash and cash equivalents: Money market funds $ 84,416 $ - $ - Total cash and cash equivalents 84,416 - - Marketable securities: Certificates of deposit - 5,296 - Commercial paper - 26,503 - Corporate debt securities - 145,169 - U.S. government securities - 1,988 - Non-U.S. government securities - 7,852 - Total marketable securities - 186,808 - Total financial assets $ 84,416 $ 186,808 $ -

Property and Equipment, net

Property and Equipment, net	9 Months Ended
Property and Equipment, net	Sep. 30, 2022
Property and Equipment, net
Property and Equipment, net	6. Property and Equipment, net Property and Equipment, net, consist of the following: (in thousands) September 30, 2022 December 31, 2021 Laboratory equipment $ 9,753 $ 8,916 Office equipment 601 621 Computer hardware and software 1,089 1,028 Furniture and fixtures 1,203 1,487 Leasehold improvements 13,487 13,409 Construction in progress 993 822 Total property and equipment 27,126 26,283 Accumulated depreciation (4,208) (2,477) $ 22,918 $ 23,806

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
Accrued Expenses and Other Current Liabilities	Sep. 30, 2022
Accrued Expenses and Other Current Liabilities
Accrued Expenses and Other Current Liabilities	7. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: (in thousands) September 30, 2022 December 31, 2021 Professional fees $ 636 $ 877 Compensation and related benefits 7,006 10,014 Research and development 5,640 8,498 Property and equipment 8 161 Other 571 500 $ 13,861 $ 20,050

Leases

Leases	9 Months Ended
Leases	Sep. 30, 2022
Leases
Leases	8. Leases On January 1, 2022, the Company adopted ASU No. 2016-02, Leases The Company was not required to record a cumulative effect adjustment upon adoption as the Company did not capitalize any material initial direct costs nor were any contracts reassessed leading to changes in the terms or contractual payments of historical arrangements that would impact expense recognition, however, the Company eliminated $3.2 million of deferred rent liabilities and $3.8 million of tenant improvement allowances as of January 1, 2022 related to the Leases as these liabilities are reflected in the operating lease ROU assets. The Company used incremental borrowing rates, or IBRs, of 9.0% and 10.0% to discount the operating lease liabilities for the Lease Agreement and the Laboratory Lease Agreement, respectively. The Company’s IBRs were quoted by an unrelated third-party lender and reflect a collateralized borrowing with similar terms and amounts as the Leases. The Company is party to a lease agreement for office space, or the Lease Agreement, in Philadelphia, Pennsylvania. The Lease Agreement commenced in February 2021 and is expected to expire in December 2031. The Company has an option to extend the term of the Lease Agreement by up to two five-year terms. This option to extend was not recognized as part of the Company's measurement of the ROU asset and operating lease liability as of September 30, 2022. The landlord provided the Company with a tenant improvement allowance of $2.8 million, for which the related expenditures were paid directly by the landlord. The Company is also party to a lease agreement for laboratory space, or the Laboratory Lease Agreement, in Hopewell, New Jersey. The laboratory is initially focused on state-of-the-art analytical capabilities, assay development and validation, and clinical product testing to support both viral vector manufacturing and clinical development. The Laboratory Lease Agreement commenced in March 2021 and is expected to expire in February 2036. The Company has an option to extend the term of the Laboratory Lease Agreement by up to two five-year terms. This option to extend was not recognized as part of the Company's measurement of the ROU asset and operating lease liability as of September 30, 2022. The landlord provided the Company with a tenant improvement allowance of The following table summarizes the Company’s operating leases: Nine Months Ended ($ in thousands) September 30, 2022 Operating lease cost $ 2,487 Cash paid for amounts included in the measurement of operating cash flows from operating leases $ 2,009 Weighted-average discount rate 9.7% Weighted-average remaining lease term (years) 12.4 The future minimum lease payments under the Company’s operating lease arrangements as of September 30, 2022 are as follows: (in thousands) 2022 (remaining) $ 845 2023 3,450 2024 3,548 2025 3,648 2026 3,751 Thereafter 33,507 Total undiscounted lease payments 48,749 Less: imputed interest (21,460) Total lease liabilities $ 27,289 The Company recognized operating lease costs of $0.8 million during both the three months ended September 30, 2022 and 2021 related to the leases. The Company recognized operating lease costs of $2.5 million during both the nine months ended September 30, 2022 and 2021 related to the leases. The future minimum lease payments under the Company’s operating lease arrangements as of December 31, 2021 were as follows: (in thousands) 2022 $ 2,884 2023 3,453 2024 3,550 2025 3,651 2026 3,754 Thereafter 33,534 $ 50,826

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2022
Commitments and Contingencies.
Commitments and Contingencies	9. Commitments and Contingencies Amended and Restated Research, Collaboration and License Arrangement with Penn The Company has a research, collaboration and licensing agreement with Penn, as amended, or the Penn Agreement, for research and development collaborations and exclusive license rights to patents for certain products and technologies. Under the Penn Agreement, the Company has obligations to fund certain research relating to the preclinical development of selected products in research programs as well as the exploratory research program in non-rare and/or non-monogenic, or large CNS indications, initially Alzheimer’s Disease, or AD, and Temporal Lobe Epilepsy, or TLE. In addition, the Company will fund discovery research conducted by Penn through August 3, 2026 and will receive exclusive rights, subject to certain limitations, to technologies resulting from the discovery research for the Company’s products developed with GTP, such as novel capsids, toxicity reduction technologies and delivery, and formulation improvements. This funding commitment for the discovery research is $5.0 million annually, paid in quarterly increments of $1.3 million through August 3, 2026. The Penn Agreement includes an exploratory research program focused on discovering targets and novel gene therapy candidates for large CNS indications, initially focused on AD and TLE, and can be expanded to other large CNS diseases upon mutual agreement. The initial term of the exploratory research program is until August 2024, which term can be extended by mutual agreement. During such term, the Company will have an exclusive right of first negotiation to include additional targets to the exploratory research program within the agreed upon large CNS indications. Under the exploratory research program, the Company will have the right to further develop and commercialize any gene therapy product candidates specific for those selected targets within AD and TLE (and any future large CNS diseases that are mutually agreed upon) that may arise from the exploratory research programs on substantially the same terms of the current Penn Agreement. Under the Penn Agreement, the Company has eight remaining options available to commence additional licensed programs for CNS indications and has until August 3, 2026, to exercise these options. If the Company were to exercise any of these options, it would owe Penn a non-refundable upfront fee of $1.0 million per product indication, with $0.5 million due upfront and another $0.5 million fee owed upon a further developmental milestone. The Company has the obligation to fund certain research relating to the preclinical development of each licensed program. The Penn Agreement requires that the Company make payments of up to (i) $16.5 million per product candidate for rare, monogenic disorders in the aggregate and (ii) $39.0 million per product candidate in the aggregate arising from the exploratory program for large CNS indications, initially AD and TLE and such other mutually agreed upon large CNS indications. Each payment will be due upon the achievement of specific development milestone events by such licensed product for a first indication, reduced development milestone payments for the second and third indications and no development milestone payments for subsequent indications. In addition, on a product-by-product basis, the Company is obligated to make up to $55.0 million in sales milestone payments on each licensed product based on annual sales of the licensed product in excess of defined thresholds. Upon successful commercialization of a product using the licensed technology, the Company is obligated to pay to Penn, on a licensed product-by-licensed product and country-by-country basis, tiered royalties (subject to customary reductions) in the mid-single digits on annual worldwide net sales of such licensed product. In addition, the Company is obligated to pay to Penn a percentage of sublicensing income, ranging from the mid-single digits to low double digits, for sublicenses under the Penn Agreement. The agreement will expire on a licensed product-by-licensed product and country-by-country basis upon the later of (i) the expiration of the last valid claim of the licensed patent rights that covers the exploitation of such licensed product in such country, and (ii) the expiration of the royalty period. In addition, the Company will pay a tiered transaction fee of 1-2% of the net proceeds upon certain change of control events. During the three months ended September 30, 2022, the Company made payments under the Penn Agreement for acquired in-process research and development of During the three months ended September 30, 2021, the Company made payments under the Penn Agreement for acquired in-process research and development of During the nine months ended September 30, 2022, the Company made payments under the Penn Agreement for acquired in-process research and development of $3.0 million related to the achievement of development milestones. During the nine months ended September 30, 2021, the Company made payments under the Penn Agreement for acquired in-process research and development of Catalent Agreements In June 2019, the Company entered into a collaboration agreement, or the Collaboration Agreement, with Catalent Maryland Inc., or Catalent. As part of the Collaboration Agreement, the Company will pay an annual fee for five years ending in 2025 for the use of the Clean Room Suite. In April 2020, the Company entered into a development services and clinical supply agreement, or the Manufacturing and Supply Agreement, with Catalent to secure clinical scale manufacturing capacity for batches of active pharmaceutical ingredients for the Company’s gene therapy product candidates. The Manufacturing and Supply Agreement confirms the terms contemplated by the Collaboration Agreement. The Collaboration Agreement continues to be in effect pursuant to its terms. Under the terms of the Manufacturing and Supply Agreement, Catalent has agreed to manufacture batches of drug product for the Company’s gene therapy product candidates at the Clean Room Suite at a Catalent facility provided for in the Collaboration Agreement. The Manufacturing and Supply Agreement provides for a term of five years which period may be extended once, at the Company’s option, for an additional five-year period. The Manufacturing and Supply Agreement also includes minimum annual purchase commitments. The Company has the right to terminate the Manufacturing and Supply Agreement for convenience or other reasons specified in the Manufacturing and Supply Agreement upon prior written notice. If the Company terminates the Manufacturing and Supply Agreement, it will be obligated to pay an early termination fee to Catalent. Under both the Collaboration Agreement and the Manufacturing and Supply Agreement, the Company has an annual minimum commitment of $10.6 million per year owed to Catalent for five years from the validation of the Clean Room, subject to certain inflationary adjustments. Employment Agreements The Company has entered into employment agreements with key personnel providing for compensation and, in certain circumstances, severance and acceleration of vesting in stock-based compensation awards, as described in the respective employment agreements. Patent Infringement Claim On February 18, 2020, the Company received a letter from REGENXBIO Inc., or Regenx, which stated its view that the use of the Company’s AAVhu68 capsid infringes patent claims to which Regenx has an exclusive license and which expire in 2024. Regenx also stated that it has exclusive licenses to various pending patent applications regarding the use of AAV vectors administered via intra-cisterna magna injection, and that these applications may lead to issued claims that Regenx believes may, if issued, cover the Company’s planned method of administration for the Company’s lead product candidates. The Company believes it has valid defenses to the issued claims set forth by Regenx relating to AAVhu68. Further, the prosecution of pending patent applications is highly uncertain, and it is unclear whether any patents will be issued from these pending Regenx patent applications at all, much less with claims that are relevant to the administration of the Company’s product candidates. Regenx also requested information regarding the Company’s relationship with Dr. Wilson while he was serving as an advisor to Regenx. Regenx's letter also offers to discuss licensing the applicable patent portfolios from them. In April 2020, the Company responded to Regenx indicating that it does not believe it requires a license to any of the specified Regenx patents or patent applications at this time, and that it found that Dr. Wilson’s relationship with the Company was consistent with his obligations to Regenx. The Company will continue to monitor the situation and, if necessary, take appropriate actions, which may include responding to further correspondence from Regenx, and engaging in discussions with Regenx regarding their claims. If any such patents were enforceable and such claims were ultimately successful, the Company might require a license to continue to use and sell any product candidates using such AAV vector. In March 2022, Penn and Regenx entered into a letter agreement that involved a release of current claims against certain Penn laboratory sponsors, including the Company, and a covenant not to sue certain Penn laboratory sponsors, including the Company, on certain future claims related to certain patent rights and other matters. The Company believes that the release and covenant provide the Company a full release of the matters raised by Regenx against the Company in the February 18, 2020 letter relating to AAVhu68 and Dr. Wilson’s relationship with the Company.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
Share-Based Compensation	Sep. 30, 2022
Share-Based Compensation
Share-Based Compensation	10. Share-Based Compensation Equity Incentive Plan The Company has three equity incentive plans: the 2018 Equity Incentive Plan, as amended, or the 2018 Plan, the 2020 Equity Incentive Plan, or the Incentive Plan, and the 2021 Equity Inducement Plan, or the Inducement Plan. New awards can only be granted under the Incentive Plan and the Inducement Plan. The total number of shares authorized under the Incentive Plan as of September 30, 2022 was 10,370,926. Of this amount, 3,910,223 shares were available for future grants as of September 30, 2022, which includes awards previously issued under the 2018 Plan that were forfeited and available for issuance under the Incentive Plan. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the Incentive Plan shall automatically increase on January 1st of each year, commencing on January 1, 2021 and continuing for ten years, in an amount equal to five percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. As a result, on January 1, 2022, the number of shares reserved for issuance under the Incentive Plan increased by 2,712,249 shares. The Incentive Plan provides for the granting of common stock, incentive stock options, nonqualified stock options, restricted stock awards, and/or stock appreciation rights to employees, directors, and other persons, as determined by the Company’s board of directors. The Company’s stock options awarded to date under the Incentive Plan vest based on requisite service period, generally over four-year periods, and have a term of ten years. The total number of shares authorized under the Inducement Plan as of September 30, 2022 was 2,000,000, as a result of an increase to the shares authorized for issuance in February 2022. Of this amount, 865,500 shares were available for future grants as of September 30, 2022. The Inducement Plan provides for the granting of nonqualified stock options and restricted stock awards to employees hired by the Company, as determined by the Company’s board of directors. The Company’s stock options awarded to date under the Inducement Plan vest based on requisite service period and have a term of ten years. The Company’s restricted stock units awarded to date under the Inducement Plan vest based on requisite service period and have a term based on each award agreement. The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. The Company recorded share-based compensation expense in the following expense categories in its accompanying statements of operations for the period presented: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2022 2021 2022 2021 Research and development $ 568 $ 2,306 $ 6,528 $ 13,155 General and administrative 2,294 4,509 8,949 11,961 $ 2,862 $ 6,815 $ 15,477 $ 25,116 During the three months ended September 30, 2022, there was no expense related to the modifications of awards. During the three months ended September 30, 2021, the Company modified certain awards and recognized an additional $0.2 million in general and administrative expenses related to the modifications. During the nine months ended September 30, 2022, the Company modified certain awards and recognized an additional $0.4 million in general and administrative expenses related to the modifications. During the nine months ended September 30, 2021, the Company modified certain awards and recognized an additional $6.1 million in research and development expenses and $0.2 million in general and administrative expenses related to the modifications. The following table summarizes stock option activity for the nine months ended September 30, 2022: Weighted Weighted average average remaining Number of exercise price contractual shares per share term (years) Outstanding at January 1, 2022 9,416,998 $ 13.72 8.6 Granted 5,707,241 3.37 Exercised (126,056) 1.02 Forfeited (3,259,306) 11.65 Outstanding at September 30, 2022 11,738,877 $ 9.40 7.3 Vested and Exercisable at September 30, 2022 5,510,147 $ 11.95 5.4 Vested or expected to vest at September 30, 2022 11,738,877 $ 9.40 7.3 The weighted-average grant date fair value of options granted was $2.52 and $13.64 for the nine months ended September 30, 2022 and 2021, respectively. As of September 30, 2022, the total unrecognized compensation expense related to unvested stock option awards was $32.6 million, which the Company expects to recognize over a weighted-average period of 2.4 years. The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below: Nine Months Ended September 30, 2022 2021 Expected volatility 92.3 % 98.9 % Risk‑free interest rate 2.6 % 0.9 % Expected term 5.8 years 6.0 years Expected dividend yield — — Restricted Stock Units The Company issues restricted stock units, or RSUs, to employees that vest over periods as determined by the board of directors. Any unvested shares are forfeited upon termination of services. The fair value of the RSUs is equal to the fair market value price of the Company’s common stock on the date of grant. Compensation expense is recognized on a straight-line basis over the vesting period of the RSUs. The following table summarizes activity related to RSU awards during the nine months ended September 30, 2022: Weighted average Number of shares grant date fair value Unvested balance at January 1, 2022 290,500 $ 14.78 Granted 261,500 4.21 Vested (20,000) 17.40 Forfeited (122,500) 12.86 Unvested balance at September 30, 2022 409,500 $ 8.48 As of September 30, 2022, the total unrecognized expense related to all RSUs was $2.5 million, which the Company expects to recognize over a weighted-average period of 2.3 years. Employee Stock Purchase Plan The Company’s 2020 Employee Stock Purchase Plan, or the ESPP, became effective on February 28, 2020. The ESPP authorizes the issuance of up to 1,435,619 shares of the Company’s common stock. Of this amount, 1,168,841 were available for future grants as of September 30, 2022. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the ESPP shall automatically increase on January 1st of each year and continuing for ten years, in an amount equal to one percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the board of directors or compensation committee to determine a lesser number of shares shall be added for such year. As a result, on January 1, 2022, the number of shares reserved for issuance under the ESPP increased by 542,449 shares, resulting in a total of 1,435,619 shares authorized for issuance. Under the ESPP, eligible employees can purchase the Company’s common stock through accumulated payroll deductions at such times as are established by the compensation committee. Eligible employees may purchase the Company’s common stock at 85% of the lower of the fair market value of the Company’s common stock on the first day of the offering period or on the last day of the offering period. The offering periods under the ESPP have a duration of six months, with periods ending in May and November of each calendar year. Eligible employees may contribute up to 15% of their eligible compensation. Under the ESPP, a participant may not accrue rights to purchase more than $25,000 worth of the Company’s common stock for each calendar year in which such right is outstanding or purchase more than 4,000 shares of the Company’s common stock in any single offering period. In accordance with the guidance in ASC 718-50 – Compensation – Stock Compensation , the ability to purchase shares of the Company’s common stock at 85% of the lower of the price on the first day of the offering period or the last day of the offering period (i.e. the purchase date) represents an option and therefore, the ESPP is a compensatory plan under this guidance. Accordingly, share-based compensation expense is determined based on the option’s grant-date fair value as estimated by applying the Black Scholes option-pricing model and is recognized over the withholding period. The Company recognized share-based compensation expense of de minimus and $0.1 million during the three months ended September 30, 2022 and 2021, respectively, and $0.2 million and $0.3 million during the nine months ended September 30, 2022 and 2021, respectively, related to the ESPP.

Subsequent Events

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2022
Subsequent Events.
Subsequent Events	11. Subsequent Events In November 2022, the Company announced plans to stop further clinical development of PBKR03 for Krabbe disease. Additionally, the Company announced a 23 percent reduction to its workforce, which will result in severance related expenses within the three months ending December 31, 2022.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2022
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying unaudited financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Updates promulgated by the Financial Accounting Standards Board, or FASB.
Interim Financial Statements	Interim Financial Statements The accompanying unaudited interim financial statements have been prepared from the books and records of the Company in accordance with GAAP for interim financial information and Rule 10-01 of Regulation S-X promulgated by the United States Securities and Exchange Commission, or SEC, which permits reduced disclosures for interim periods. All adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the accompanying balance sheets, statements of operations, stockholders’ equity, and cash flows have been made. Although these interim financial statements do not include all of the information and footnotes required for complete annual financial statements, management believes the disclosures are adequate to make the information presented not misleading. Unaudited interim results of operations and cash flows are not necessarily indicative of the results that may be expected for the full year. Unaudited interim financial statements and footnotes should be read in conjunction with the audited financial statements and footnotes included in the Company’s 2021 Annual Report filed on Form 10-K.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are periodically reviewed and the effects of the revisions are reflected in the accompanying financial statements in the period they are determined to be necessary.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Management believes that the carrying amounts of the Company’s financial instruments, including cash equivalents, prepaid expenses, and accounts payable, approximate fair value due to the short-term nature of those instruments.
Concentration of credit risk	Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash, cash equivalents, and marketable securities.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly-liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash equivalents as of September 30, 2022 consisted of money market funds, certificates of deposits, corporate debt securities and commercial paper. Cash consists of cash deposits at banking institutions.
Marketable securities	Marketable securities The Company classifies its marketable securities as available-for-sale, which include commercial paper, certificates of deposit, corporate debt securities and United States, or U.S., government debt securities with original maturities of greater than three months. These securities are carried at fair market value, with unrealized gains and losses reported in comprehensive loss and accumulated other comprehensive income (loss) within stockholders’ equity. Gains or losses on marketable securities sold are recognized on the specific identification method.
Share-based compensation	Share-based compensation The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. Estimating the fair value of share-based awards requires the input of subjective assumptions, including, for stock options, stock price volatility. The Company accounts for forfeitures for stock option awards as they occur. The Company uses the Black-Scholes option pricing model to value its stock option awards. The assumptions used in estimating the fair value of share-based awards represent management's estimate and involve inherent uncertainties and the application of management's judgment. As a result, if factors change and management uses different assumptions, share-based compensation expense could be materially different for future awards. The expected term of the stock options is estimated using the "simplified method," as the Company has limited historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses a composite of comparable public company data as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option.
Net Loss Per Share	Net Loss Per Share Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period. Diluted loss per share of common stock includes the effect, if any, from the potential exercise or conversion of securities, such as stock options, which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive: Nine Months Ended 2022 2021 Stock options 11,738,877 9,581,659 Unvested restricted stock units 409,500 238,333 Employee stock purchase plan 62,488 49,528 12,210,865 9,869,520
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “ Leases” Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, “ Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments ”, or ASU 2016-13, which replaces the incurred loss impairment methodology under current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 was subsequently updated by ASU No. 2019-04, “ Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ”, to clarify that entities should include recoveries when estimating the allowance for credit losses. This guidance is effective for the Company for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022 and must be adopted using a modified retrospective approach, with certain exceptions. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures and does not expect a material impact to financial statements or disclosures .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
Summary of Significant Accounting Policies (Tables)	Sep. 30, 2022
Summary of Significant Accounting Policies
Schedule of antidilutive securities excluded from computation of earnings per share	Nine Months Ended 2022 2021 Stock options 11,738,877 9,581,659 Unvested restricted stock units 409,500 238,333 Employee stock purchase plan 62,488 49,528 12,210,865 9,869,520

Cash, cash equivalents and ma_2

Cash, cash equivalents and marketable securities (Tables)	9 Months Ended
Cash, cash equivalents and marketable securities (Tables)	Sep. 30, 2022
Cash, cash equivalents and marketable securities
Schedule of details regarding the Company's portfolio of cash and cash equivalents	Cost or (in thousands) Amortized cost Unrealized gains Unrealized losses Fair value September 30, 2022: Cash accounts in banking institutions $ 25,453 $ - $ - $ 25,453 Money market funds 15,721 - - 15,721 Certificates of deposit 7,032 - (2) 7,030 Corporate debt securities 554 - (1) 553 Commercial paper 13,817 - (6) 13,811 Total $ 62,576 $ - $ (9) $ 62,568 December 31, 2021 Cash accounts in banking institutions $ 44,549 $ - $ - $ 44,549 Money market funds 84,416 - - 84,416 Total $ 128,965 $ - $ - $ 128,965
Schedule of details regarding the Company's portfolio of marketable securities	(in thousands) Amortized cost Unrealized gains Unrealized losses Fair value September 30, 2022: Certificates of deposit $ 22,012 $ 2 $ (96) $ 21,918 Commercial paper 49,451 1 (118) 49,334 Corporate debt securities 79,188 - (1,198) 77,990 U.S. government securities 1,998 - (50) 1,948 Total $ 152,649 $ 3 $ (1,462) $ 151,190 December 31, 2021 Certificates of deposit $ 5,296 $ - $ - $ 5,296 Commercial paper 26,503 4 (4) 26,503 Corporate debt securities 145,577 10 (418) 145,169 U.S. government securities 1,996 - (8) 1,988 Non-U.S. government securities 7,849 4 (1) 7,852 Total $ 187,221 $ 18 $ (431) $ 186,808

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
Fair Value of Financial Instruments (Tables)	Sep. 30, 2022
Fair Value of Financial Instruments
Summary of assets measured at fair value on a recurring basis	Fair value measurement at reporting date using Quoted prices in active Significant markets for other Significant identical observable unobservable assets inputs inputs (in thousands) (Level 1) (Level 2) (Level 3) September 30, 2022: Assets Cash and cash equivalents: Certificates of deposit $ - $ 7,030 $ - Money market funds 15,721 - $ - Commercial paper - 13,811 - Corporate debt securities - 553 - Total cash and cash equivalents 15,721 21,394 - Marketable securities: Certificates of deposit - 21,918 - Commercial paper - 49,334 - Corporate debt securities - 77,990 - U.S. government securities - 1,948 - Total marketable securities - 151,190 - Total financial assets $ 15,721 $ 172,584 $ - December 31, 2021 Assets Cash and cash equivalents: Money market funds $ 84,416 $ - $ - Total cash and cash equivalents 84,416 - - Marketable securities: Certificates of deposit - 5,296 - Commercial paper - 26,503 - Corporate debt securities - 145,169 - U.S. government securities - 1,988 - Non-U.S. government securities - 7,852 - Total marketable securities - 186,808 - Total financial assets $ 84,416 $ 186,808 $ -

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
Property and Equipment, net (Tables)	Sep. 30, 2022
Property and Equipment, net
Schedule of property and equipment, net	(in thousands) September 30, 2022 December 31, 2021 Laboratory equipment $ 9,753 $ 8,916 Office equipment 601 621 Computer hardware and software 1,089 1,028 Furniture and fixtures 1,203 1,487 Leasehold improvements 13,487 13,409 Construction in progress 993 822 Total property and equipment 27,126 26,283 Accumulated depreciation (4,208) (2,477) $ 22,918 $ 23,806

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Sep. 30, 2022
Accrued Expenses and Other Current Liabilities
Schedule of accrued liabilities and other current liabilities	(in thousands) September 30, 2022 December 31, 2021 Professional fees $ 636 $ 877 Compensation and related benefits 7,006 10,014 Research and development 5,640 8,498 Property and equipment 8 161 Other 571 500 $ 13,861 $ 20,050

Leases (Tables)

Leases (Tables)	9 Months Ended
Leases (Tables)	Sep. 30, 2022
Leases
Schedule of operating lease cost	Nine Months Ended ($ in thousands) September 30, 2022 Operating lease cost $ 2,487 Cash paid for amounts included in the measurement of operating cash flows from operating leases $ 2,009 Weighted-average discount rate 9.7% Weighted-average remaining lease term (years) 12.4
Schedule of future minimum rental payments for operating leases	(in thousands) 2022 (remaining) $ 845 2023 3,450 2024 3,548 2025 3,648 2026 3,751 Thereafter 33,507 Total undiscounted lease payments 48,749 Less: imputed interest (21,460) Total lease liabilities $ 27,289 (in thousands) 2022 $ 2,884 2023 3,453 2024 3,550 2025 3,651 2026 3,754 Thereafter 33,534 $ 50,826

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
Share-Based Compensation (Tables)	Sep. 30, 2022
Share-Based Compensation
Schedule of share-based compensation expense category	Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2022 2021 2022 2021 Research and development $ 568 $ 2,306 $ 6,528 $ 13,155 General and administrative 2,294 4,509 8,949 11,961 $ 2,862 $ 6,815 $ 15,477 $ 25,116
Summary of stock option activity plan	Weighted Weighted average average remaining Number of exercise price contractual shares per share term (years) Outstanding at January 1, 2022 9,416,998 $ 13.72 8.6 Granted 5,707,241 3.37 Exercised (126,056) 1.02 Forfeited (3,259,306) 11.65 Outstanding at September 30, 2022 11,738,877 $ 9.40 7.3 Vested and Exercisable at September 30, 2022 5,510,147 $ 11.95 5.4 Vested or expected to vest at September 30, 2022 11,738,877 $ 9.40 7.3
Schedule of weighted average assumptions applied to options	Nine Months Ended September 30, 2022 2021 Expected volatility 92.3 % 98.9 % Risk‑free interest rate 2.6 % 0.9 % Expected term 5.8 years 6.0 years Expected dividend yield — —
Summary of activity related to restricted stock unit	Weighted average Number of shares grant date fair value Unvested balance at January 1, 2022 290,500 $ 14.78 Granted 261,500 4.21 Vested (20,000) 17.40 Forfeited (122,500) 12.86 Unvested balance at September 30, 2022 409,500 $ 8.48

Risks and Liquidity (Details)

Risks and Liquidity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended
	Jan. 31, 2021	Sep. 30, 2022	Dec. 31, 2021
Risks And Liquidity [Line Items]
Accumulated deficit		$ (465,335)	$ (356,281)
Follow-on public offering
Risks And Liquidity [Line Items]
Shares issued	8,050,000
Share price	$ 22
Net proceeds	$ 165,800

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Jan. 01, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Amount of antidilutive securities excluded from computation of earnings per share	12,210,865	9,869,520
Operating lease liability	$ 27,289
Right-of-use assets	$ 19,890
Accounting Standards Update 2016-02
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Operating lease liability			$ 27,300
Right-of-use assets			$ 20,400
Stock options (including shares subject to repurchase)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Amount of antidilutive securities excluded from computation of earnings per share	11,738,877	9,581,659
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Amount of antidilutive securities excluded from computation of earnings per share	409,500	238,333
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Amount of antidilutive securities excluded from computation of earnings per share	62,488	49,528

Cash, cash equivalents and ma_3

Cash, cash equivalents and marketable securities - Portfolio of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Cash and cash equivalents
Cost or Amortized cost	$ 62,576	$ 128,965
Unrealized losses	(9)
Fair value	62,568	128,965
Cash accounts in banking institutions
Cash and cash equivalents
Cost or Amortized cost	25,453	44,549
Fair value	25,453	44,549
Certificates of deposit
Cash and cash equivalents
Cost or Amortized cost	7,032
Unrealized losses	(2)
Fair value	7,030
Money market funds
Cash and cash equivalents
Cost or Amortized cost	15,721	84,416
Fair value	15,721	$ 84,416
Commercial paper
Cash and cash equivalents
Cost or Amortized cost	13,817
Unrealized losses	(6)
Fair value	13,811
Corporate debt securities
Cash and cash equivalents
Cost or Amortized cost	554
Unrealized losses	(1)
Fair value	$ 553

Cash, cash equivalents and ma_4

Cash, cash equivalents and marketable securities - Portfolio of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	$ 152,649	$ 187,221
Unrealized gains	3	18
Unrealized losses	(1,462)	(431)
Fair value	151,190	186,808
Certificates of deposit
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	22,012	5,296
Unrealized gains	2
Unrealized losses	(96)
Fair value	21,918	5,296
Commercial paper
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	49,451	26,503
Unrealized gains	1	4
Unrealized losses	(118)	(4)
Fair value	49,334	26,503
Corporate debt securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	79,188	145,577
Unrealized gains		10
Unrealized losses	(1,198)	(418)
Fair value	77,990	145,169
U.S. government securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	1,998	1,996
Unrealized losses	(50)	(8)
Fair value	$ 1,948	1,988
Non-U.S. government securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost		7,849
Unrealized gains		4
Unrealized losses		(1)
Fair value		$ 7,852

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 62,568	$ 128,965
Marketable securities	151,190	186,808
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	21,918	5,296
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	49,334	26,503
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	77,990	145,169
U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	1,948	1,988
Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		7,852
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	15,721	84,416
Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	7,030
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	13,811
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	553
Level 1 \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	15,721	84,416
Total financial assets	15,721	84,416
Level 1 \| Recurring \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	15,721	84,416
Level 2 \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	21,394
Marketable securities	151,190	186,808
Total financial assets	172,584	186,808
Level 2 \| Recurring \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	21,918	5,296
Level 2 \| Recurring \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	49,334	26,503
Level 2 \| Recurring \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	77,990	145,169
Level 2 \| Recurring \| U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	1,948	1,988
Level 2 \| Recurring \| Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		$ 7,852
Level 2 \| Recurring \| Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	7,030
Level 2 \| Recurring \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	13,811
Level 2 \| Recurring \| Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 553

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 27,126	$ 26,283
Accumulated depreciation	(4,208)	(2,477)
Total, property plant and equipment net	22,918	23,806
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	9,753	8,916
Office equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	601	621
Computer hardware and software.
Property, Plant and Equipment [Line Items]
Total property and equipment	1,089	1,028
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	1,203	1,487
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	13,487	13,409
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 993	$ 822

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued Expenses and Other Current Liabilities
Professional fees	$ 636	$ 877
Compensation and related benefits	7,006	10,014
Research and development	5,640	8,498
Property and equipment	8	161
Other	571	500
Accrued expenses and other current liabilities	$ 13,861	$ 20,050

Leases (Details)

Leases (Details) $ in Thousands	3 Months Ended		9 Months Ended
Leases (Details) $ in Thousands	Sep. 30, 2022 USD ($) item	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) item	Sep. 30, 2021 USD ($)	Jan. 01, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Rent expense	$ 800	$ 800	$ 2,500	$ 2,500
Deferred rent					$ 3,200	$ 6,921
Tenant improvement allowances liability					3,800
Operating lease liability	27,289		27,289
Right-of-use assets	19,890		19,890
Future minimum lease payments
2022 (remaining)	845		845
2023	3,450		3,450			2,884
2024	3,548		3,548			3,453
2025	3,648		3,648			3,550
2026	3,751		3,751			3,651
2026						3,754
Thereafter						33,534
Thereafter	33,507		33,507
Total Undiscounted lease payments	48,749		48,749			$ 50,826
Less: imputed interest	(21,460)		(21,460)
Total Lease Liabilities	27,289		27,289
Other current assets
Lessee, Lease, Description [Line Items]
Tenant improvements	$ 100		$ 100
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease liability					27,300
Right-of-use assets					20,400
Future minimum lease payments
Total Lease Liabilities					$ 27,300
Operating Leases For Office Space
Lessee, Lease, Description [Line Items]
Incremental borrowing rate	9%		9%
Operating Leases For Laboratory Space
Lessee, Lease, Description [Line Items]
Incremental borrowing rate	10%		10%
Maximum \| Operating Leases For Office Space
Lessee, Lease, Description [Line Items]
Number of extension terms \| item	2		2
Extended term of new lease agreement			5 years
Tenant improvement allowance	$ 2,800		$ 2,800
Maximum \| Operating Leases For Laboratory Space
Lessee, Lease, Description [Line Items]
Number of extension terms \| item	2		2
Extended term of new lease agreement			5 years
Tenant improvement allowance	$ 1,300		$ 1,300

Leases - Operating lease cost (

Leases - Operating lease cost (Details) $ in Thousands	9 Months Ended
Leases - Operating lease cost (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Leases
Operating lease cost	$ 2,487
Cash paid for amounts included in the measurement of operating cash flows from operating leases	$ 2,009
Weighted-average discount rate	9.70%
Weighted-average remaining lease term (years)	12 years 4 months 24 days

Commitments and Contingencies -

Commitments and Contingencies - Collaboration Agreements (Details) $ in Millions		1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 03, 2020 USD ($) Option	Aug. 31, 2021	Apr. 30, 2020 USD ($)	Jun. 30, 2019	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development milestone payment					$ 0		$ 0
Catalent Maryland, Inc. (Catalent)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual fee payable, term				5 years
Period for which annual fee is payable			5 years
Term of manufacturing and supply agreement			5 years
Additional extension term of manufacturing and supply agreement			5 years
Minimum amount agreed to purchase in batches of drug product			$ 10.6
Amended and restated agreement with Penn
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual fee payable	$ 5
Quarterly fee payable	$ 1.3
Number of CNS indications \| Option	8
Upfront payments	$ 1
Upfront fee payable upon clinical candidate designation	0.5
Upfront fee due	$ 0.5
Payments for technology license fee						$ 5			$ 5
Additional technology license fee paid					1.5		3	$ 0.5	$ 1.5
Payment made on option exercise						$ 0.5		$ 0.5
Amount payable per product candidate arising from the exploratory program for large CNS indications					39		39
Sales milestone payments					55		55
Amended and restated agreement with Penn \| Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration agreement, tiered transaction fee percent		1%
Amended and restated agreement with Penn \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration agreement, tiered transaction fee percent		2%
Amount payable per product candidate for rare, monogenic disorders					$ 16.5		$ 16.5

Share-Based Compensation - Equi

Share-Based Compensation - Equity Incentive Plan & ESPP (Details)			3 Months Ended		9 Months Ended
	Jan. 01, 2022 shares	Feb. 28, 2020 USD ($) shares	Sep. 30, 2022 USD ($) shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) plan shares	Sep. 30, 2021 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans \| plan					3
Number of shares purchased		4,000
Share-based compensation expense \| $			$ 2,862,000	$ 6,815,000	$ 15,477,000	$ 25,116,000
Equity Incentive Plan 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized			10,370,926		10,370,926
Shares available for future grant			3,910,223		3,910,223
Period till which there is automatic increase in rights granted under the Plan					10 years
Percent of the total number of shares of the Company's common stock outstanding					5%
Term of award					10 years
Vesting period					4 years
Additional number of common shares reserved for future issuance	2,712,249
Equity Inducement Plan 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized			2,000,000		2,000,000
Shares available for future grant			865,500		865,500
Term of award					10 years
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	1,435,619	1,435,619
Shares available for future grant			1,168,841		1,168,841
Additional number of common shares reserved for future issuance	542,449
Period till which there is automatic increase in rights granted under ESPP		10 years
Percentage of common stock outstanding		1%
Percentage of stock purchase price		85%
Percentage of maximum employee contribution		15%
Maximum amount of common stock that can be purchased \| $		$ 25,000
Share-based compensation expense \| $			$ 100,000	$ 100,000	$ 200,000	$ 300,000

Share-Based Compensation - Shar

Share-Based Compensation - Share-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 Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,862	$ 6,815	$ 15,477	$ 25,116
Share-based compensation expense due to modifications	0
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	568	2,306	6,528	13,155
Share-based compensation expense due to modifications				6,100
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 2,294	4,509	8,949	11,961
Share-based compensation expense due to modifications		$ 200	$ 400	$ 200

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Number of shares
Outstanding, Beginning of period	9,416,998
Granted	5,707,241
Exercised	(126,056)
Forfeited	(3,259,306)
Outstanding, Ending of period	11,738,877		9,416,998
Vested and Exercisable at September 30, 2022	5,510,147
Vested or expected to vest at September 30, 2022	11,738,877
Weighted average exercise price per share
Outstanding, Beginning of period	$ 13.72
Granted	3.37
Exercised	1.02
Forfeited	11.65
Outstanding, Ending of period	9.40		$ 13.72
Vested and Exercisable at September 30, 2022	11.95
Vested or expected to vest at September 30, 2022	$ 9.40
Weighted average remaining contractual term (years)
Outstanding	7 years 3 months 18 days		8 years 7 months 6 days
Vested and Exercisable at September 30, 2022	5 years 4 months 24 days
Vested or expected to vest at September 30, 2022	7 years 3 months 18 days
Weighted average grant date fair value of options granted	$ 2.52	$ 13.64
Unrecognized compensation expense related to unvested stock option awards	$ 32.6
Weighted average period for recognition	2 years 4 months 24 days

Share-Based Compensation - Assu

Share-Based Compensation - Assumptions Used in Determining Fair Value & Early exercise of Stock Options (Details)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility	92.30%	98.90%
Risk-free interest rate	2.60%	0.90%
Expected term	5 years 9 months 18 days	6 years

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Stock Units (Details) - Unvested restricted stock units - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Number of shares
Unvested balance, Beginning	290,500
Granted	261,500
Vested	(20,000)
Forfeited	(122,500)
Unvested balance, Ending	409,500
Weighted average grant date fair value
Unvested balance, Weighted average grant date fair value, Beginning	$ 8.48	$ 14.78
Granted, Weighted average grant date fair value	4.21
Vested, Weighted average grant date fair value	17.40
Forfeited, Weighted average grant date fair value	12.86
Unvested balance, Weighted average grant date fair value, Ending	$ 8.48
Total unrecognized expense	$ 2.5
Weighted-average remaining contractual term	2 years 3 months 18 days

Subsequent Events (Details)

Subsequent Events (Details)	Nov. 30, 2022
Subsequent Events
Subsequent Events
Percent of percent reduction to our workforce	23%