PepGen (PEPG) 10-Q 12 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 12, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Registrant Name	PEPGEN INC.
Entity Central Index Key	0001835597
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		23,631,924
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	PEPG
Security Exchange Name	NASDAQ
Entity File Number	001-41374
Entity Tax Identification Number	85-3819886
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	245 Main Street
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	781
Local Phone Number	797-0979
Document Quarterly Report	true
Document Transition Report	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 218,817	$ 132,895
Other receivables	4,230	4,744
Prepaid expenses and other current assets	3,433	2,347
Total current assets	226,480	139,986
Property and equipment, net	2,843	636
Other assets	1,473	3,019
Total assets	230,796	143,641
Current liabilities:
Accounts payable	5,392	3,240
Accrued expenses	15,185	7,081
Total current liabilities	20,577	10,321
Preferred stock warrant liability		226
Total liabilities	20,577	10,547
Commitments and contingencies (Note 7)
Convertible preferred stock		165,176
Stockholders' equity (deficit)
Common stock	2
Additional paid-in capital	279,629	1,653
Accumulated other comprehensive (loss) income	(99)	17
Accumulated deficit	(69,313)	(33,752)
Total stockholders' equity (deficit)	210,219	(32,082)
Total liabilities, convertible preferred stock, and stockholders' equity (deficit)	$ 230,796	$ 143,641

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating Expenses [Abstract]
Research and development	$ 14,240	$ 3,216	$ 24,947	$ 8,746
General and administrative	3,401	1,976	6,587	3,074
Total operating expenses	17,641	5,192	31,534	11,820
Operating loss	(17,641)	(5,192)	(31,534)	(11,820)
Other income (expense)
Interest income	250		259
Other income (expense), net	76	(197)	134	(205)
Total other income (expense), net	326	(197)	393	(205)
Net loss before income tax	(17,315)	(5,389)	(31,141)	(12,025)
Income tax expense			(4,420)
Net loss	$ (17,315)	$ (5,389)	$ (35,561)	$ (12,025)
Net loss per share, basic	$ (1.23)	$ (6.03)	$ (4.70)	$ (13.45)
Net loss per share, diluted	$ (1.23)	$ (6.03)	$ (4.70)	$ (13.45)
Weighted-average common shares outstanding, basic	14,090,455	894,060	7,563,283	894,060
Weighted-average common shares outstanding, diluted	14,090,455	894,060	7,563,283	894,060

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (17,315)	$ (5,389)	$ (35,561)	$ (12,025)
Cumulative translation adjustment arising during the period	(42)	(3)	(116)	23
Comprehensive loss	$ (17,357)	$ (5,392)	$ (35,677)	$ (12,002)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (UNAUDITED) - USD ($) $ in Thousands	Total	Series A-1 Convertible Preferred Stock	Series A-2 Convertible Preferred Stock	Series B Convertible Preferred Stock	Common Stock Class A Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Temporary Equity Beginning Balance at Dec. 31, 2020		$ 8,454	$ 7,680
Temporary Equity Beginning Balance, shares at Dec. 31, 2020		1,372,970	700,278
Beginning Balance at Dec. 31, 2020	$ (6,360)					$ 119	$ (8)	$ (6,471)
Beginning Balance, shares at Dec. 31, 2020					894,060
Stock-based compensation expense	188					188
Net loss	(6,636)							(6,636)
Foreign currency translation adjustment	26						26
Temporary Equity Ending Balance at Mar. 31, 2021		$ 8,454	$ 7,680
Temporary Equity Ending Balance, shares at Mar. 31, 2021		1,372,970	700,278
Ending Balance at Mar. 31, 2021	(12,782)					307	18	(13,107)
Ending Balance, shares at Mar. 31, 2021					894,060
Temporary Equity Beginning Balance at Dec. 31, 2020		$ 8,454	$ 7,680
Temporary Equity Beginning Balance, shares at Dec. 31, 2020		1,372,970	700,278
Beginning Balance at Dec. 31, 2020	(6,360)					119	(8)	(6,471)
Beginning Balance, shares at Dec. 31, 2020					894,060
Net loss	(12,025)
Temporary Equity Ending Balance at Jun. 30, 2021		$ 8,454	$ 23,659
Temporary Equity Ending Balance, shares at Jun. 30, 2021		1,372,970	2,100,836
Ending Balance at Jun. 30, 2021	(17,845)					636	15	(18,496)
Ending Balance, shares at Jun. 30, 2021					894,060
Temporary Equity Beginning Balance at Mar. 31, 2021		$ 8,454	$ 7,680
Temporary Equity Beginning Balance, shares at Mar. 31, 2021		1,372,970	700,278
Beginning Balance at Mar. 31, 2021	(12,782)					307	18	(13,107)
Beginning Balance, shares at Mar. 31, 2021					894,060
Temporary equity, Issuance of Series A-2 convertible preferred stock, net of issuance cost, shares			1,400,558
Temporary equity, Issuance of Series A-2 convertible preferred stock, net of issuance cost			$ 15,979
Issuance of Common Stock upon initial public offering and Series A-2 convertible preferred stock, net of underwritings' fees and issuance cost	329					329
Net loss	(5,389)							(5,389)
Foreign currency translation adjustment	(3)						(3)
Temporary Equity Ending Balance at Jun. 30, 2021		$ 8,454	$ 23,659
Temporary Equity Ending Balance, shares at Jun. 30, 2021		1,372,970	2,100,836
Ending Balance at Jun. 30, 2021	(17,845)					636	15	(18,496)
Ending Balance, shares at Jun. 30, 2021					894,060
Temporary Equity Beginning Balance at Dec. 31, 2021	165,176	$ 8,454	$ 44,639	$ 112,083
Temporary Equity Beginning Balance, shares at Dec. 31, 2021		1,372,970	3,939,069	7,234,766
Beginning Balance at Dec. 31, 2021	(32,082)					1,653	17	(33,752)
Beginning Balance, shares at Dec. 31, 2021					963,588
Stock-based compensation expense	815					815
Net loss	(18,246)							(18,246)
Foreign currency translation adjustment	(74)						(74)
Temporary Equity Ending Balance at Mar. 31, 2022		$ 8,454	$ 44,639	$ 112,083
Temporary Equity Ending Balance, shares at Mar. 31, 2022		1,372,970	3,939,069	7,234,766
Ending Balance at Mar. 31, 2022	(49,587)					2,468	(57)	(51,998)
Ending Balance, shares at Mar. 31, 2022					963,588
Temporary Equity Beginning Balance at Dec. 31, 2021	165,176	$ 8,454	$ 44,639	$ 112,083
Temporary Equity Beginning Balance, shares at Dec. 31, 2021		1,372,970	3,939,069	7,234,766
Beginning Balance at Dec. 31, 2021	(32,082)					1,653	17	(33,752)
Beginning Balance, shares at Dec. 31, 2021					963,588
Net loss	(35,561)
Temporary Equity Ending Balance at Jun. 30, 2022
Ending Balance at Jun. 30, 2022	210,219				$ 2	279,629	(99)	(69,313)
Ending Balance, shares at Jun. 30, 2022					23,562,395
Temporary Equity Beginning Balance at Mar. 31, 2022		$ 8,454	$ 44,639	$ 112,083
Temporary Equity Beginning Balance, shares at Mar. 31, 2022		1,372,970	3,939,069	7,234,766
Beginning Balance at Mar. 31, 2022	(49,587)					2,468	(57)	(51,998)
Beginning Balance, shares at Mar. 31, 2022					963,588
Stock-based compensation expense	1,228					1,228
Temporary equity, Issuance of Series A-2 stock upon exercise of warrants, shares			35,529
Temporary equity, Issuance of Series A-2 stock upon exercise of warrants			$ 574
Temporary equity, Conversion of convertible preferred stock upon initial public offering, shares		(1,372,970)	(3,974,598)	(7,234,766)
Temporary equity, Conversion of convertible preferred stock upon initial public offering		$ (8,454)	$ (45,213)	$ (112,083)
Conversion of convertible preferred stock upon initial public offering, shares					12,359,856
Conversion of convertible preferred stock upon initial public offering	165,752				$ 1	165,751
Issuance of Common Stock upon initial public offering and Series A-2 convertible preferred stock, net of underwritings' fees and issuance cost, shares					10,238,951
Issuance of Common Stock upon initial public offering and Series A-2 convertible preferred stock, net of underwritings' fees and issuance cost	110,183				$ 1	110,182
Net loss	(17,315)							(17,315)
Foreign currency translation adjustment	(42)						(42)
Temporary Equity Ending Balance at Jun. 30, 2022
Ending Balance at Jun. 30, 2022	$ 210,219				$ 2	$ 279,629	$ (99)	$ (69,313)
Ending Balance, shares at Jun. 30, 2022					23,562,395

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (PARENTHETICAL) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Common Stock
Net of issuance costs	$ 12,684
Series A-2 Convertible Preferred Stock
Net of issuance costs		$ 21

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (35,561)	$ (12,025)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation	205	84
Stock-based compensation expense	2,043	517
Change in fair value of preferred stock warrant liability	(58)	193
Changes in operating assets and liabilities:
Other receivables	26	(366)
Prepaids and other current and non-current assets	(926)	(1,690)
Accounts payable	1,434	1,099
Accrued expenses and other non-current liabilities	7,926	3,223
Net cash used in operating activities	(24,911)	(8,965)
Cash flows from investing activities:
Purchases of property and equipment	(2,223)	(320)
Net cash used in investing activities	(2,223)	(320)
Cash flows from financing activities:
Issuance of common stock upon initial public offering, net of underwriters' fees	114,267
Payment of offering costs	(1,277)	(173)
Proceeds from the exercise of Series A-2 warrants	406
Proceeds from issuance of Series A-2 convertible preferred stock, net of issuance costs		15,988
Issuance costs of Series B convertible preferred stock		(2)
Net cash provided by financing activities	113,396	15,813
Effect of exchange rate changes on cash	(340)	20
Net increase in cash, cash equivalents and restricted cash	85,922	6,548
Cash, cash equivalents and restricted cash at beginning of period	134,368	9,778
Cash, cash equivalents and restricted cash at end of period	220,290	16,326
Components of cash, cash equivalents and restricted cash
Cash and cash equivalents	218,817	16,326
Restricted Cash	1,473
Total cash, cash equivalents and restricted cash at end of period	220,290	16,326
Supplemental noncash investing and financing activities
Property and equipment included in accounts payable and accrued expenses	244
Deferred offering costs in accounts payable and accrued expenses	$ 1,420	40
Series A-2 Convertible Preferred stock issuance costs included in accrued expenses		8
Series B convertible preferred stock issuance costs included in accrued expenses		$ 27

Nature of Business and Basis of

Nature of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation PepGen Inc., or the Company or PepGen, headquartered in Boston, Massachusetts, is a biopharmaceutical company developing a transformative oligonucleotide delivery technology and pipeline of product candidates to treat neuromuscular and neurologic diseases with a high unmet medical need. Initial Public Offering On May 10, 2022, the Company closed its initial public offering (IPO) in which the Company sold an aggregate of 9,000,000 shares at a public offering price of $ 12.00 per share for gross proceeds of $ 108.0 million. In connection with the IPO, the Company granted the underwriters a 30-day option to purchase 1,350,000 additional shares of common stock. On May 16, 2022, the underwriters exercised the option in part and the Company issued 1,238,951 shares of common stock for gross proceeds of $ 14.9 million. From the IPO and option exercise by the underwriters, the Company received approximately $ 122.9 million in gross proceeds and $ 110.2 million in net proceeds, after deducting underwriting discounts and estimated offering expenses payable by the Company. Immediately prior to consummation of the IPO, all 12,546,805 outstanding shares of the Company’s redeemable convertible preferred stock, and 35,529 preferred stock warrants that were exercised on May 4, 2022 (see Note 3), converted into 12,359,856 shares of the Company’s common stock. As a result of this conversion, the Company's net loss per share, basic and diluted, will be significantly different in future filings. Liquidity and Capital Resources Since inception, the Company has not generated any revenue from product sales or other sources and has incurred significant operating losses and negative cash flows from operations. The Company’s primary uses of cash and cash equivalents to date have been to fund research and development activities, business planning, establishing and maintaining the Company’s intellectual property portfolio, hiring personnel, leasing premises and associated capital expenditures, raising capital, and providing general and administrative support for these operations. As of June 30, 2022, the Company had an accumulated deficit of $ 69.3 million. To date, the Company has funded operations primarily through private placements of convertible preferred stock and its IPO. As of June 30, 2022, the Company had cash and cash equivalents of $ 218.8 million. As the Company continues to pursue its business plan to successfully develop and obtain regulatory approval for the Company’s product candidates, it expects to finance its operations through the sale of equity, debt financings or other capital resources, which could include income from collaborations, strategic partnerships or marketing, distribution, licensing or other strategic arrangements with third parties, or from grants. However, there can be no assurance that any additional financing or strategic transactions will be available to the Company on acceptable terms, if at all. If events or circumstances occur such that the Company does not obtain additional funding, it may need to delay, reduce or eliminate its product development or future commercialization efforts, which could have a material adverse effect on the Company’s business, results of operations or financial condition. Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements are unaudited and have been prepared in conformity with generally accepted accounting principles in the United States of America (GAAP). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). The condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. These condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position as of June 30, 2022, and results of operations for the interim periods ended June 30, 2022 and June 30, 2021. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These condensed consolidated financial statements should be read in conjunction with the audited financial statements as of and for the years ended December 31, 2021 and 2020, and the notes thereto, included in the Company’s final prospectus related to the IPO, dated May 5, 2022 and filed with the Securities and Exchange Commission (the SEC) pursuant to Rule 424(b)(4) on May 9, 2022 (Final Prospectus).

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited financial statements for the years ended December 31, 2021 and 2020 included in the Final Prospectus. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies. Deferred Offering Costs The Company capitalized incremental legal, professional accounting and other third-party fees that were directly associated with the IPO as other non-current assets until the IPO was consummated. After consummation of the IPO, these costs were recorded in stockholders’ equity as a reduction of additional paid-in-capital generated as a result of the offering. The IPO was completed in May 2022 and deferred offering costs totaling $ 4.1 million were recorded within stockholders’ equity as a reduction of additional paid-in-capital generated from the initial public offering. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts or existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of enactment. The Company records a valuation allowance to reduce deferred tax assets to an amount for which realization is more likely than not. The Company recognizes the tax benefit from an uncertain tax position if it is more likely than not that the tax position will be sustained upon examination by the tax authorities, based on the merits of the position. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits. Restricted Cash The Company classifies all cash whose use is limited by contractual provisions as restricted cash. Restricted cash arises from the requirement for the Company to maintain cash of $ 1.5 million as collateral under a lease agreement. As of June 30, 2022 and December 31, 2021, the Company had $ 1.5 million of restricted cash classified in other assets on the condensed consolidated balance sheets. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), The amendment relates to leases to increase transparency and comparability among organizations by requiring the recognition of right-of-use, or the ROU, assets obtained in exchange for lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of condensed consolidated financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The amendment is effective for the Company as of January 1, 2022. As of January 1, 2022, the Company does not have any leases with initial terms greater than twelve months that have commenced for accounting purposes. For any future leases with initial terms greater than twelve months, the Company will record a lease liability and corresponding ROU asset on is balance sheet and provide required disclosures under Topic 842.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following tables (in thousands) present information about the Company’s financial assets that have been measured at fair value as of June 30, 2022 and December 31, 2021, and indicate the fair value of the hierarchy of the valuation inputs utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair value determined by Level 2 inputs utilize observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities. Fair values determined by Level 3 inputs are unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. As of June 30, 2022 Total Level 1 Level 2 Level 3 US Treasury-backed money market funds $ 216,641 $ 216,641 $ — $ — Total $ 216,641 $ 216,641 $ — $ — As of December 31, 2021 Total Level 1 Level 2 Level 3 US Treasury-backed money market funds $ 30,719 $ 30,719 $ — $ — Total $ 30,719 $ 30,719 $ — $ — Money market funds are highly liquid investments that are valued based on quoted market prices in active markets, which represent a Level 1 measurement within the fair value hierarchy. Preferred stock warrant liability In connection with the November 24, 2020 Stock Purchase Agreement (Note 8), the Company granted warrants to purchase up to 35,529 shares of Series A-2 convertible preferred stock at a price per share equal to $ 11.42 and with a term ending upon the earlier of an underwritten public offering pursuant to an effective registration statement under the Securities Act of 1933, the consummation of a Deemed Liquidation Event, as such term is defined in the Company’s Restated Certificate of Incorporation or 10 years . As the warrants are for preferred stock, which do not qualify for equity classification, the warrants were recorded as a liability and are required to be remeasured to fair value at each reporting date. The warrants were exercised on May 4, 2022 , just prior to the completion of the IPO, for proceeds of $ 0.4 million. Immediately prior to the consummation of the IPO, the warrants were converted into 34,901 shares of the Company's common stock. As there are a number of inputs that are not observable in the market, the warrant valuation represented a Level 3 measurement within the fair value hierarchy. The Company’s valuation of the preferred stock warrant utilized the Black-Scholes option-pricing model, which incorporates assumptions and estimates to value the preferred stock warrant. The quantitative elements associated with the Company’s Level 3 inputs impacting the fair value measurement of the preferred stock warrant liability included the fair value per share of the underlying Series A-2 convertible preferred stock, the remaining contractual term of the warrant, risk-free interest rate, expected dividend yield and expected volatility of the price of the underlying preferred stock. The most significant assumption in the Black-Scholes option-pricing model impacting the fair value of the preferred stock warrant was the fair value of the Company’s Series A-2 convertible preferred stock as of each remeasurement date. The Company determined the fair value per share of the underlying preferred stock by taking into consideration its most recent sales of its convertible preferred stock. The Company historically had been a private company and lacked company-specific historical and implied volatility information of its stock. Therefore, it estimated its expected stock volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrant. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrant. The Company had estimated a 0 % dividend yield based on the expected dividend yield and the fact that the Company has never paid or declared dividends. The Company recognized changes in the fair value of the warrant liability as a component of other income (expense) in its condensed consolidated statements of operations and comprehensive loss. A reconciliation of the Level 3 warrant liability is as follows (in thousands): Series A-2 Preferred Balance as of December 31, 2020 $ 30 Change in fair value 196 Balance as of December 31, 2021 226 Change in fair value ( 58 ) Balance as of March 31, 2022 168 Exercise of preferred stock warrants ( 168 ) Balance as of June 30, 2022 $ —

Property and Equipment, Net

Property and Equipment, Net	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	4. Property and Equipment, Net The cost and accumulated depreciation of property and equipment were as follows (in thousands): June 30, December 31, Lab equipment $ 2,795 $ 975 Computer and office equipment $ 47 $ 91 Construction in process 416 — Total property and equipment 3,258 1,066 Less: accumulated depreciation ( 415 ) ( 430 ) Total property and equipment, net $ 2,843 $ 636 Depreciation expense was $ 0.1 million and $ 0.1 million for the three months ended June 30, 2022 and June 30, 2021, respectively. Depreciation expense was $ 0.2 million and $ 0.1 million for the six months ended June 30, 2022 and June 30, 2021, respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2022
Accrued Liabilities, Current [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following (in thousands): June 30, December 31, Research and development expenses $ 8,495 $ 5,343 Employee-related expenses 1,070 1,205 Taxes payable 4,001 — Other 1,619 533 Total accrued expenses $ 15,185 $ 7,081

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	6. Related Party Transactions Technology license agreement In March 2018, the Company, Oxford University Innovation Limited (OUI), and the Medical Research Council of United Kingdom Research and Innovation, or MRC (or collectively the Licensors), entered into a license of technology agreement, or the License Agreement, which was subsequently amended in December 2018 and further amended and restated in November 2020. The Licensors and affiliates hold shares of the Company's common stock. The License Agreement provides the Company with an exclusive world-wide license to licensed data and technology owned by OUI and MRC in respect of cell penetrating peptides for treatment of Duchenne muscular dystrophy, spinal muscular atrophy, and other conditions. The License Agreement provides the Company with the rights to grant and authorize sublicenses to make, use, sell, and import products and otherwise exploit the patent rights. As consideration for the license, the Company made an initial upfront payment in 2018 of $ 0.1 million upon transfer of the license technology and data and in 2020 upon amending and restating the License Agreement made two additional payments each of $ 19,000 for a Restatement Completion Fee and License Data Fee. The Company determined that the upfront payment and subsequent Restatement Completion Fee and License Data Fee as part of the license agreement would be expensed upon execution of the original contract and subsequent amendment as the license was acquired for research and development purposes which does not have alternative future uses, and the underlying technology has not reached technological feasibility. The Company could be required to make milestone payments to the Licensors upon completion of certain patent and commercial milestones related to the patents and commercialization of certain of the Company’s product candidates. The aggregate potential milestone payments are $ 0.1 million. The Company also agreed to pay the Licensors low single digit royalties on net sales of any licensed products that are commercialized by the Company or sublicensees in excess of a threshold amount between £ 20 million and £ 30 million ($ 24.6 million and $ 36.9 million as of June 30, 2022), subject to certain adjustments. The term of the License Agreement continues until the later of (i) the date on which all the patents and patent applications covered thereunder have been abandoned or allowed to lapse or expired or been rejected or revoked or (ii) 20 years from the date of the original agreement. Upon completion of the Company’s IPO in May 2022, the Company became obligated to pay OUI an exit fee between 0.5 % to 2 % of the value determined in an acquisition or IPO, not to exceed £ 5 million ($ 6.2 million as of the IPO date) (See Note 6). The exit fee due to OUI, based on the IPO raise, was $ 1.4 million, which was paid during the second quarter of 2022 and charged to research and development expense. Additionally, the Company pays office space rent to OUI. For the three and six months ended June 30, 2022 total rent expense and other costs paid to OUI and affiliates was $ 0.1 million and $ 0.2 million, in each case. Services agreement In November 2020, the Company entered into an agreement, or the Services Agreement, with Carnot Pharma, LLC, or Carnot, under which Carnot provides research and other services to the Company. Carnot is an entity controlled by RA Capital Management, L.P. Entities affiliated with RA Capital Management, L.P. purchased shares of Series A-2 convertible preferred stock in the Company’s preferred stock financing in November of 2020 and May and July of 2021, which were converted to shares of the Company's common stock in connection with the IPO. In addition, entities affiliated with RA Capital Management, L.P. purchased shares of our Series B convertible preferred stock in the Company’s preferred stock financing in July 2021 which were also converted into shares of the Company's common stock in connection with the IPO. One member of the Company’s Board of Directors is also affiliated with RA Capital Management, L.P. Under the terms of the Services Agreement, the Company compensates Carnot on a fully burdened cost basis for personal time devoted to Company projects. In addition, the Company reimburses Carnot on a costs basis for any subcontractor costs incurred. The Company pays Carnot on a quarterly basis, in arrears, for services performed and costs incurred. The Services Agreement is for a term of the later of (A) two ( 2 ) years and (B) the later of (a) completion of the Services or (b) latest-to-occur delivery of a final report or any other items required to be delivered to the Company under the last ongoing project as part of the services, if any. The Company may terminate the services agreement by giving 30 days’ prior notice and either party can terminate the services agreement for a material breach, if not cured within 30 days following notice by the nonbreaching party. The services agreement was terminated on April 15, 2022 . Expenses incurred by the Company under the Services Agreement with Carnot for the six months ended June 30, 2022 and June 30, 2021, totaled $ 0.1 million and $ 0.4 million, respectively. As of June 30, 2022 and December 31, 2021, included in accounts payable was approximately $ 0 and $ 2,600 that was due to Carnot by the Company for services rendered under the Services Agreement, respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Legal proceedings From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. The Company is not party to any litigation and does not have contingency reserves established for any litigation liabilities. Leases In December 2021, the Company entered into a lease for lab and office space in Massachusetts of approximately 31,668 square feet. The lease term is for 110 months with one optional renewal period of five years . The initial monthly lease payment is $ 0.2 million which increases on an annual basis at three percent. The lease is expected to commence for accounting purposes when the landlord tenders possession of the premises to the Company, which is expected to occur in the fourth quarter of 2022 or early 2023. Other The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the agreements, the Company agrees to indemnify, hold harmless, and to reimburse the indemnified party for losses suffered or incurred by the indemnified party, including in connection with any U.S. patent or any copyright or other intellectual property infringement claim by any third-party with respect to the Company’s products. Further, the Company indemnifies its directors and officers who are, or were, serving at the Company’s request in such capacities. The Company’s maximum exposure under these arrangements is unknown as of June 30, 2022. The Company does not anticipate recognizing any significant losses relating to these arrangements. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements may be unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements.

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Equity	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Convertible Preferred Stock and Stockholders' Equity	8. Convertible Preferred Stock and Stockholders’ Equity Reverse Stock Split On April 29, 2022, the Company filed a charter amendment to affect a 1.018 for 1 reverse stock split of its issued and outstanding shares of common stock, which resulted in a proportional adjustment to the existing conversion ratios for each series of the Company’s preferred stock. Accordingly, all share and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. Series A-1 convertible preferred stock and Series A-2 convertible preferred stock In connection with the November 24, 2020, Stock Purchase Agreement, the Company agreed to issue an aggregate of 3,939,069 shares of Series A-2 convertible preferred stock to new and existing investors at a price of $ 11.42 per share, in three closings, and elected to convert 1,348,693 shares of outstanding Class A and Class B common stock into 1,372,970 shares of Series A-1 convertible preferred stock. A total of 1,033,117 shares of Class A common stock held by certain founding investors and employees were not modified and continue to exist as Class A common stock. The Series A-1 and Series A-2 convertible preferred stock was converted to common stock immediately prior to the consummation of the Company’s IPO in May 2022 (see Note 1). Series B convertible preferred stock In July 2021 the Company entered into the Series B Stock Purchase Agreement, whereby the Company agreed to issue and sold an aggregate of 7,234,766 shares of Series B convertible stock to new and existing investors at a per share price of $ 15.55 per share for aggregate gross proceeds of $ 112.5 million. The Series B convertible preferred stock was converted to common stock immediately prior to the consummation of the Company's IPO in May 2022 (see Note 1). Common stock Under the Third Amended and Restated Certificate of Incorporation, dated May 10, 2022, the Company has the authority to issue a total of 500,000,000 shares of common stock (par value of $ 0.0001 per share) and 10,000,000 shares of undesignated preferred stock (par value of $ 0.0001 per share). In connection with the IPO, the Company re-designated all shares of Class A common stock as shares of common stock. Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No cash dividends have been declared by the board of directors during the six months ended June 30, 2022 and June 30, 2021. The Company has reserved the following shares of common stock for issuance, on an as-converted basis, as follows: June 30, December 31, Convertible preferred stock — 12,546,805 Stock options issued and outstanding 3,205,378 1,898,084 Preferred stock warrants issued and outstanding — 35,529 Vesting conditions placed on previously issued common shares 69,529 69,529 Authorized for future stock awards or option grants 1,114,975 456,416 Authorized for future issuance under employee stock purchase plan 226,000 — Total 4,615,882 15,006,363 Shares of Common Stock Subject to Repurchase In November 2020, in connection with the Series A-2 convertible preferred stock financing, two founding stockholders entered into Stock Restriction Agreements, or Restriction Agreements, whereby 139,057 shares that were previously vested and not subject to repurchase became restricted and subject to repurchase. The repurchase rights lapse 50 % on the one-year anniversary of the Restriction Agreements and 50 % on the second anniversary of the Restriction Agreements. Shares subject to repurchase by the Company are not deemed, for accounting purposes, to be outstanding until those shares vest and therefore are not included in the shares outstanding on the condensed consolidated balance sheet. In connection with the vesting restrictions placed on these previously vested shares, the Company was required to determine the measurement date fair value of the shares, which was $ 2.37 per share or $ 0.3 million in aggregate. The measurement date fair value of the restricted stock will be recognized as stock-based compensation expense over the vesting period. As of June 30, 2022, and December 31 2021, 69,529 shares were subject to repurchase by the Company.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation As of June 30, 2022, the Company maintains three equity compensation plans, the PepGen Inc. 2020 Stock Plan, or 2020 Plan, the 2022 Stock Option and Incentive Plan, or 2022 Plan, and the 2022 Employee Stock Purchase Plan, or ESPP. The 2022 Plan replaced the 2020 Plan, and the Company will not make additional awards under the 2020 Plan. As of June 30, 2022, 1,114,975 shares remain available for issuance under the 2022 Plan and 226,000 shares remain available for issuance under the ESPP. Stock Option Activity Stock option activity under the 2020 Plan and 2022 Plan, is as follows: Stock Weighted-Average Outstanding as of December 31, 2021 1,898,084 $ 7.46 Granted 1,321,986 $ 11.90 Exercised — $ — Canceled/Forfeited ( 14,692 ) $ 8.80 Outstanding as of June 30, 2022 3,205,378 $ 9.29 The weighted-average grant date fair value of options granted during the six months ended June 30, 2022 was $ 7.82 per share. Stock-Based Compensation Expense Stock based compensation expense recognized for stock option grants included in the accompanying condensed consolidated statements of operations and comprehensive loss is as follows (in thousands): Three Months Ended Six Months Ended 2022 2021 2022 2021 Research and development $ 372 $ 17 $ 628 $ 40 General and administrative 857 312 1,415 477 Total stock-based compensation expense $ 1,229 $ 329 $ 2,043 $ 517 As of June 30, 2022, total unrecognized compensation cost related to unvested share options was approximately $ 16.8 million, which is expected to be recognized over a weighted-average period of approximately 3.5 years.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company recorded income tax expense of nil for the three months ended June 30, 2022 and 2021, respectively. The Company recorded income tax expense of $ 4.4 million and nil for the six months ended June 30, 2022 and 2021, respectively. The income tax expense for the six months ended June 30, 2022 was due to the intellectual property (IP) transfer noted in the paragraph below. On January 1, 2022 (the “Transfer Date”), the Company’s wholly owned subsidiary, PepGen Limited, transferred all IP assets to the parent company, PepGen Inc., in an arm’s length transaction at fair value pursuant to an asset transfer agreement. The fair value of the IP assets is a non-recurring fair value measurement. The Company engaged valuation specialists to calculate the IP value, and the IP value was measured using the historical cost method. The historical cost method estimated the fair value of the IP assets using the historical cost base of the IP assets and the expected market return as of the Transfer Date. The significant assumption inherent in estimating the fair value using the historical cost method was the expected market return. The Company utilized a 40 % expected market return, which a third-party investor may expect as a return on their investment, and which is based on studies of venture capital investment returns. The Company calculated the fair value of the IP assets by computing the present value of the historical cost base using the 40 % expected market return. The expected market rate assumption used in the estimation of the IP assets represents a level 3 inputs of the fair value hierarchy (see Note 3). The Company recognizes the impact of an uncertain income tax position taken on its income tax returns at the amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will be recognized if it has less than a 50% likelihood of being sustained. The tax positions are analyzed at least quarterly, and adjustments are made as events occur that warrant adjustments for those positions. As of June 30, 2022, the Company has recognized a liability for the uncertain tax position relative to the IP transfer of $ 0.7 million. The transfer of the intellectual property assets resulted in an estimated tax charge to Her Majesty’s Revenue & Customs, after considering net operating loss carryforwards, of $ 4.4 million, inclusive of the $ 0.7 million uncertain tax position. The liability is accounted for in accrued expenses on the condensed consolidated balance sheet, and was $ 4.0 million as of June 30, 2022 after currency translation.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Deferred Offering Costs	Deferred Offering Costs The Company capitalized incremental legal, professional accounting and other third-party fees that were directly associated with the IPO as other non-current assets until the IPO was consummated. After consummation of the IPO, these costs were recorded in stockholders’ equity as a reduction of additional paid-in-capital generated as a result of the offering. The IPO was completed in May 2022 and deferred offering costs totaling $ 4.1 million were recorded within stockholders’ equity as a reduction of additional paid-in-capital generated from the initial public offering.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts or existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of enactment. The Company records a valuation allowance to reduce deferred tax assets to an amount for which realization is more likely than not. The Company recognizes the tax benefit from an uncertain tax position if it is more likely than not that the tax position will be sustained upon examination by the tax authorities, based on the merits of the position. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.
Restricted Cash	Restricted Cash The Company classifies all cash whose use is limited by contractual provisions as restricted cash. Restricted cash arises from the requirement for the Company to maintain cash of $ 1.5 million as collateral under a lease agreement. As of June 30, 2022 and December 31, 2021, the Company had $ 1.5 million of restricted cash classified in other assets on the condensed consolidated balance sheets.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), The amendment relates to leases to increase transparency and comparability among organizations by requiring the recognition of right-of-use, or the ROU, assets obtained in exchange for lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of condensed consolidated financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The amendment is effective for the Company as of January 1, 2022. As of January 1, 2022, the Company does not have any leases with initial terms greater than twelve months that have commenced for accounting purposes. For any future leases with initial terms greater than twelve months, the Company will record a lease liability and corresponding ROU asset on is balance sheet and provide required disclosures under Topic 842.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Summary of Fair Value of Financial Assets Measure at Fair Value on Recurring Basis	The following tables (in thousands) present information about the Company’s financial assets that have been measured at fair value as of June 30, 2022 and December 31, 2021, and indicate the fair value of the hierarchy of the valuation inputs utilized to determine such fair value. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair value determined by Level 2 inputs utilize observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities. Fair values determined by Level 3 inputs are unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. As of June 30, 2022 Total Level 1 Level 2 Level 3 US Treasury-backed money market funds $ 216,641 $ 216,641 $ — $ — Total $ 216,641 $ 216,641 $ — $ — As of December 31, 2021 Total Level 1 Level 2 Level 3 US Treasury-backed money market funds $ 30,719 $ 30,719 $ — $ — Total $ 30,719 $ 30,719 $ — $ —
Summary of Reconciliation of Warrant Liabilities	A reconciliation of the Level 3 warrant liability is as follows (in thousands): Series A-2 Preferred Balance as of December 31, 2020 $ 30 Change in fair value 196 Balance as of December 31, 2021 226 Change in fair value ( 58 ) Balance as of March 31, 2022 168 Exercise of preferred stock warrants ( 168 ) Balance as of June 30, 2022 $ —

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Summary of Cost and Accumulated Depreciation of Property and Equipment	The cost and accumulated depreciation of property and equipment were as follows (in thousands): June 30, December 31, Lab equipment $ 2,795 $ 975 Computer and office equipment $ 47 $ 91 Construction in process 416 — Total property and equipment 3,258 1,066 Less: accumulated depreciation ( 415 ) ( 430 ) Total property and equipment, net $ 2,843 $ 636

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2022
Accrued Liabilities, Current [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): June 30, December 31, Research and development expenses $ 8,495 $ 5,343 Employee-related expenses 1,070 1,205 Taxes payable 4,001 — Other 1,619 533 Total accrued expenses $ 15,185 $ 7,081

Convertible Preferred Stock a_2

Convertible Preferred Stock and Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Issuance, on an As-Converted Basis	The Company has reserved the following shares of common stock for issuance, on an as-converted basis, as follows: June 30, December 31, Convertible preferred stock — 12,546,805 Stock options issued and outstanding 3,205,378 1,898,084 Preferred stock warrants issued and outstanding — 35,529 Vesting conditions placed on previously issued common shares 69,529 69,529 Authorized for future stock awards or option grants 1,114,975 456,416 Authorized for future issuance under employee stock purchase plan 226,000 — Total 4,615,882 15,006,363

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock Options Activity	Stock option activity under the 2020 Plan and 2022 Plan, is as follows: Stock Weighted-Average Outstanding as of December 31, 2021 1,898,084 $ 7.46 Granted 1,321,986 $ 11.90 Exercised — $ — Canceled/Forfeited ( 14,692 ) $ 8.80 Outstanding as of June 30, 2022 3,205,378 $ 9.29
Summary of Stock-based Compensation Expense	Stock based compensation expense recognized for stock option grants included in the accompanying condensed consolidated statements of operations and comprehensive loss is as follows (in thousands): Three Months Ended Six Months Ended 2022 2021 2022 2021 Research and development $ 372 $ 17 $ 628 $ 40 General and administrative 857 312 1,415 477 Total stock-based compensation expense $ 1,229 $ 329 $ 2,043 $ 517

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			6 Months Ended
	May 16, 2022	May 10, 2022	Jun. 30, 2022	May 04, 2022	Dec. 31, 2021	Jun. 30, 2021
Subsidiary, Sale of Stock [Line Items]
Received from IPO and option exercise by underwriters			$ 122,900
Net Received from IPO and option exercise by underwriters			110,200
Accumulated deficit			69,313		$ 33,752
Cash and cash equivalents			$ 218,817		$ 132,895	$ 16,326
Common stock
Subsidiary, Sale of Stock [Line Items]
Common stock issued in connection with exercise of stock options	1,238,951
Gross proceeds from underwriters exercised option	$ 14,900
IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares sold		9,000,000
Public offering price per share		$ 12
Gross proceeds from sale of shares		$ 108,000
Shares issued upon conversion of redeemable convertible preferred stock				12,359,856
Preferred stock warrants exercised				35,529
IPO | Redeemable Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Outstanding shares				12,546,805
IPO | Common stock
Subsidiary, Sale of Stock [Line Items]
Option to purchase		1,350,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Additional Information) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Summary of Significant Accounting Policies [Line Items]
Deferred offering costs	$ 4,100,000
Cash	1,500,000
Unrecognized tax benefits, interest on income taxes expense	0
Unrecognized tax benefits, income tax penalties	0
Other Assets
Summary of Significant Accounting Policies [Line Items]
Restricted cash	$ 1,500,000	$ 1,500,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value of Financial Assets Measure at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	$ 216,641	$ 30,719
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	216,641	30,719
US Treasury-Backed Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	216,641	30,719
US Treasury-Backed Money Market Funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	$ 216,641	$ 30,719

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ / shares in Units, $ in Thousands		6 Months Ended
	May 04, 2022 USD ($) shares	Jun. 30, 2022 USD ($)	Nov. 24, 2020 $ / shares shares
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Warrants term			10 years
Warrants exercised, date		May 04, 2022
Proceeds from warrant exercises | $		$ 406
Dividend Yield
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected dividend yield			0
Series A-2 Convertible Preferred Stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of warrants purchase granted			35,529
Preferred stock par value | $ / shares			$ 11.42
IPO
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of warrants purchase granted	35,529
Proceeds from warrant exercises | $	$ 400
Class of warrants or rights number of shares converted into common stock	34,901

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Reconciliation of Warrant Liabilities (Details) - Series A-2 Preferred Stock Warrant Liability - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 168	$ 226	$ 30
Change in fair value		(58)	196
Exercise of preferred stock warrants	$ (168)
Ending balance		$ 168	$ 226

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Cost and Accumulated Depreciation of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,258	$ 1,066
Less: accumulated depreciation	(415)	(430)
Total property and equipment, net	2,843	636
Lab Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	2,795	975
Computer and Office Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	47	$ 91
Construction in Process
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 416

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Depreciation expenses	$ 0.1	$ 0.1	$ 0.2	$ 0.1

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accrued Liabilities, Current [Abstract]
Research and development expenses	$ 8,495	$ 5,343
Employee-related expenses	1,070	1,205
Taxes payable	4,001
Other	1,619	533
Total accrued expenses	$ 15,185	$ 7,081

Related Party Transactions - Ad

Related Party Transactions - Additional Information) (Details) £ in Millions			1 Months Ended		3 Months Ended	6 Months Ended
	May 31, 2022 USD ($)	May 31, 2022 EUR (€)	Nov. 30, 2020	Mar. 31, 2018 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2022 GBP (£)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Technology License Agreement
Related Party Transaction [Line Items]
Initial upfront payment				$ 100,000
Additional payments of restatement completion fee and license data fee one						$ 19,000
Additional payments of restatement completion fee and license data fee two						19,000
Aggregate potential milestone payments						$ 100,000
Term of license agreement						20 years	20 years
Technology License Agreement | Minimum
Related Party Transaction [Line Items]
Sublicensees threshold amount						$ 24,600,000	£ 20
Technology License Agreement | Maximum
Related Party Transaction [Line Items]
Sublicensees threshold amount						36,900,000	£ 30
Technology License Agreement | Oxford University Innovation Limited | IPO
Related Party Transaction [Line Items]
Required to pay exit fee amount						1,400,000
Technology License Agreement | Oxford University Innovation Limited | IPO | Minimum
Related Party Transaction [Line Items]
Percentage of exit fee	0.50%	0.50%
Technology License Agreement | Oxford University Innovation Limited | IPO | Maximum
Related Party Transaction [Line Items]
Percentage of exit fee	2%	2%
Required to pay exit fee amount	$ 6,200,000	€ 5,000,000
Technology License Agreement | OUI and Affiliates
Related Party Transaction [Line Items]
Rent expense					$ 100,000	200,000
Other costs paid					100,000	200,000
Services Agreement [Member] | Carnot Pharma, LLC
Related Party Transaction [Line Items]
Term of services agreement			2 years
Services agreement terminate prior notice period			30 days
Services agreement terminated date			Apr. 15, 2022
Related party transaction expenses						100,000		$ 400,000
Due to related party for service rendered					$ 0	$ 0			$ 2,600

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - Massachusetts $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)	Dec. 31, 2021 ft²
Commitments and contingencies [Line Items]
Leased space | ft²		31,668
Lease term	110 months
Option to extend lease term description	The lease term is for 110 months with one optional renewal period of five years
Option to extend lease term	true
Renewal period	5 years
Initial monthly lease payments | $	$ 0.2
Percentage of lease payments increase on annual basis	3%

Convertible Preferred Stock a_3

Convertible Preferred Stock and Stockholders' Equity - Additional Information (Details)			1 Months Ended		6 Months Ended
	Apr. 29, 2022	Nov. 24, 2020 $ / shares shares	Jul. 31, 2021 USD ($) $ / shares shares	Nov. 30, 2020 USD ($) Stockholder $ / shares shares	Jun. 30, 2022 USD ($) Vote $ / shares shares	Jun. 30, 2021 USD ($)	Dec. 31, 2021 shares
Class of Stock [Line Items]
Reverse stock split, description	1.018 for 1 reverse stock split
Gross proceeds from issuance of convertible preferred stock | $						$ 15,988,000
Reverse stock split, conversion ratio	0.982
Common stock, shares authorized					500,000,000
Common stock, par value | $ / shares					$ 0.0001
Cash dividend | $					$ 0	$ 0
Number of common stock vote | Vote					1
Series A-2 Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock par value | $ / shares		$ 11.42
Undesignated Preferred Stock
Class of Stock [Line Items]
Preferred stock authorized					10,000,000
Preferred stock par value | $ / shares					$ 0.0001
Stock Purchase Agreement | Series A-2 Convertible Preferred Stock
Class of Stock [Line Items]
Number of shares agreed to issue		3,939,069
Price per share | $ / shares		$ 11.42
Stock Purchase Agreement | Class A and Class B Common Stock
Class of Stock [Line Items]
Common stock, shares outstanding		1,348,693
Stock Purchase Agreement | Series A-1 Convertible Preferred Stock
Class of Stock [Line Items]
Number of shares converted		1,372,970
Stock Purchase Agreement | Class A Common Stock
Class of Stock [Line Items]
Common stock, shares outstanding		1,033,117
Series B Stock Purchase Agreement | Series B Convertible Preferred Stock
Class of Stock [Line Items]
Number of shares agreed to issue			7,234,766
Price per share | $ / shares			$ 15.55
Gross proceeds from issuance of convertible preferred stock | $			$ 112,500,000
Stock Restriction Agreements
Class of Stock [Line Items]
Number of shares became restricted and subject to repurchase				139,057
Number of founding stockholders entered | Stockholder				2
Percentage of repurchase rights lapse on one-year anniversary.				50%
Percentage of repurchase rights lapse on second anniversary				50%
Measurement date fair value of shares vested per share | $ / shares				$ 2.37
Measurement date aggregate fair value of shares | $				$ 300,000
Shares subject to repurchase					69,529		69,529

Convertible Preferred Stock a_4

Convertible Preferred Stock and Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Issuance, on an As-Converted Basis (Details) - shares	Jun. 30, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Reserved shares of common stock for issuance	4,615,882	15,006,363
Convertible Preferred Stock
Class of Stock [Line Items]
Reserved shares of common stock for issuance		12,546,805
Stock Options Issued and Outstanding
Class of Stock [Line Items]
Reserved shares of common stock for issuance	3,205,378	1,898,084
Preferred Stock Warrants Issued and Outstanding
Class of Stock [Line Items]
Reserved shares of common stock for issuance		35,529
Vesting Conditions Placed on Previously Issued Common Shares
Class of Stock [Line Items]
Reserved shares of common stock for issuance	69,529	69,529
Authorized for Future Stock Awards or Option Grants
Class of Stock [Line Items]
Reserved shares of common stock for issuance	1,114,975	456,416
Authorized for Future Issuance under Employee Stock Purchase Plan
Class of Stock [Line Items]
Reserved shares of common stock for issuance	226,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average grant date fair value of options granted | $ / shares	$ 7.82
Unrecognized compensation cost related to unvested share options | $	$ 16.8
Expected recognition period of unrecognized compensation cost related to unvested share options	3 years 6 months
2022 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares authorized and reserved for issuance	1,114,975
2022 Employee Stock Purchase Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares authorized and reserved for issuance	226,000

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Options Activity (Details) - 2020 Plan and 2022 Plan	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock Options Outstanding as of December 31, 2021 | shares	1,898,084
Stock Options, Granted | shares	1,321,986
Stock Options, Canceled/Forfeited | shares	(14,692)
Stock Options, Outstanding as of June 30, 2022 | shares	3,205,378
Weighted Average Exercise Price, Outstanding as of December 31, 2021 | $ / shares	$ 7.46
Weighted Average Exercise Price, Granted | $ / shares	11.90
Weighted average exercise price, canceled/forfeited | $ / shares	8.80
Weighted Average Exercise Price, Outstanding as of June 30, 2022 | $ / shares	$ 9.29

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 1,229	$ 329	$ 2,043	$ 517
Research and development
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	372	17	628	40
General and administrative
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 857	$ 312	$ 1,415	$ 477

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Taxes [Line Items]
Income tax expense				$ 4,420
Uncertain tax position		700		700
Expected market return	40%
Her Majesty's Revenue and Customs | Accrued Expenses
Income Taxes [Line Items]
Income tax liabilities		4,400		4,400
Uncertain tax position		700		700
After currency translation amount		$ 4,000		$ 4,000