PEPG PepGen Inc

 

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

 

FORM 8-K

 

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): February 24, 2025

 

 

PepGen Inc.

(Exact name of Registrant as Specified in Its Charter)

 

 

Delaware			001-41374	85-3819886
(State or Other Jurisdiction of Incorporation)			(Commission File Number)	(IRS Employer Identification No.)
321 Harrison Avenue 8th Floor
Boston, Massachusetts				02118
(Address of Principal Executive Offices)				(Zip Code)

 

Registrant’s Telephone Number, Including Area Code: (781) 797-0979

 

(Former Name or Former Address, if Changed Since Last Report)

 

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common stock, par value $0.0001 per share		PEPG		Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

 

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Item 2.02 Results of Operations and Financial Condition.

On February 24, 2025, PepGen Inc. (the "Company") announced its financial results for the year ended December 31, 2024 and issued a press release titled "PepGen Reports Fourth Quarter and Year-End 2024 Financial Results and Recent Corporate Highlights". A copy of the press release is furnished as Exhibit 99.1.

 

The information provided in this Current Report on Form 8-K (this “Form 8-K”), including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any of the Company’s filings under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 7.01 Regulation FD Disclosure.

The Company will host a conference call and webcast on February 24, 2025 at 8:00 a.m. Eastern time, during which it expects to discuss the initial results from the ongoing FREEDOM-DM1 trial in patients with myotonic dystrophy type 1 (DM1). Directions on how to access the conference call and a summary of the initial data are included in the Company’s press release titled “PepGen Announces Positive Initial Results, Including Robust Splicing Correction, from Ongoing FREEDOM-DM1 Trial in Patients with DM1” furnished as Exhibit 99.2 hereto. A copy of the slide deck that will be presented during the conference call is furnished as Exhibit 99.3 hereto.

The information in this Item 7.01 of this Form 8-K, including Exhibits 99.2 and 99.3, shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act or the Exchange Act, except as expressly set forth by specific reference in such a filing. This Form 8-K (including the exhibits hereto) will not be deemed an admission as to the materiality of any information required to be disclosed solely to satisfy the requirements of Regulation FD.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number	Description
99.1	Press Release issued by PepGen Inc. on February 24, 2025 titled "PepGen Reports Fourth Quarter and Year-End 2024 Financial Results and Recent Corporate Highlights"
99.2	Press Release issued by PepGen Inc. on February 24, 2025 titled "PepGen Announces Positive Initial Results, Including Robust Splicing Correction, from Ongoing FREEDOM-DM1 Trial in Patients with DM1"
99.3	Corporate Presentation titled “FREEDOM-DM1 5 and 10 mg/kg Clinical Data Update”
104	Cover Page Interactive Data File (embedded within Inline XBRL document)

 

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			PepGen Inc.
Date:	February 24, 2025	By:	/s/ Noel Donnelly
			Noel Donnelly, Chief Financial Officer

 

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PepGen Reports Fourth Quarter and Year-End 2024 Financial Results and Recent Corporate Highlights

– The Company today reported positive initial results from the ongoing FREEDOM-DM1 trial in patients with DM1; mean splicing correction of 12.3% and 29.1% in 5 and 10 mg/kg cohorts, respectively –

– FREEDOM-DM1 15 mg/kg cohort is dosing, with results expected in second half of 2025 –

– CONNECT1-EDO51 10 mg/kg cohort is fully enrolled, with results expected in third quarter of 2025 –

BOSTON— February 24, 2025-- PepGen Inc. (Nasdaq: PEPG), a clinical-stage biotechnology company advancing the next generation of oligonucleotide therapies with the goal of transforming the treatment of severe neuromuscular and neurological diseases, today reported financial results for the quarter and year-ended December 31, 2024, and recent corporate highlights.

“Today, we reported initial results from FREEDOM-DM1, which showed robust splicing correction in patients with DM1 following a single dose of PGN-EDODM1. We believe these data contribute to the growing evidence of our novel EDO platform’s potential to deliver the drug to the nucleus, the site of action,” said James McArthur, PhD, President and CEO of PepGen. “We remain dedicated to our mission of developing life-changing therapeutics for patients with neuromuscular diseases and are committed to demonstrating the ability of our investigational candidates to address the root cause of disease for improved patient outcomes. We have numerous key data milestones expected this year and look forward to announcing clinical results from the 15 mg/kg cohort of FREEDOM and 10 mg/kg cohort of CONNECT1-EDO51.”

Recent Program Updates

PGN-EDODM1: Myotonic Dystrophy Type 1 (DM1)

 

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PGN-EDO51: Duchenne Muscular Dystrophy (DMD)

 

 

Financial Results for the Three and Twelve Months Ended December 31, 2024

 

 

About PGN-EDODM1

PGN-EDODM1, PepGen's investigational candidate in development for the treatment of DM1, utilizes the Company's proprietary EDO technology to deliver a therapeutic oligonucleotide that is designed to restore the normal splicing function of MBNL1, a key RNA splicing protein. PGN-EDODM1 is designed to directly address the deleterious effects of cytosine-uracil-guanine (CUG) repeat expansion in the DMPK transcripts which sequester MBNL1, by binding to the pathogenic CUG trinucleotide repeat expansion

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present in the DMPK transcripts, disrupting the binding between the CUG repeat expansion and MBNL1. We believe this mechanism will allow the DMPK transcripts to continue performing its normal function within the cell, while also liberating MBNL1 to correct downstream mis-splicing events. We believe that this innovative therapeutic approach has considerable advantages over oligonucleotide modalities that rely on knockdown or degradation of the DMPK transcripts. We believe that this therapeutic strategy positions us to potentially provide clinically meaningful benefits for DM1 patients while mitigating the risk of potential deleterious outcomes. The FDA has granted PGN-EDODM1 both Orphan Drug and Fast Track Designations for the treatment of patients with DM1.

 

About PGN-EDO51

PGN-EDO51, PepGen's investigational candidate in development for the treatment of DMD, utilizes the Company's proprietary EDO technology to deliver a therapeutic oligonucleotide that is designed to target the root cause of this devastating disease. PGN-EDO51 is designed to skip exon 51 of the dystrophin transcript, an established therapeutic target for approximately 13% of DMD patients, thereby aiming to restore the open reading frame and enabling the production of a truncated, yet functional dystrophin protein. The FDA has granted PGN-EDO51 both Orphan Drug and Rare Pediatric Disease Designations for the treatment of patients with DMD amenable to an exon-51 skipping approach.

 

About PepGen

PepGen is a clinical-stage biotechnology company advancing the next generation of oligonucleotide therapies with the goal of transforming the treatment of severe neuromuscular and neurological diseases. PepGen’s EDO platform is founded on over a decade of research and development and leverages cell-penetrating peptides to improve the uptake and activity of conjugated oligonucleotide therapeutics. Using these EDO peptides, we are generating a pipeline of oligonucleotide therapeutic candidates designed to target the root cause of serious diseases.

 

For more information, please visit PepGen.com. Follow PepGen on LinkedIn and X.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “intends,” “may,” “plans,” “possible,” “potential,” “seeks,” “will,” and variations of these words or similar expressions that are intended to identify forward-looking statements. Any such statements in this press release that are not statements of historical fact may be deemed to be forward-looking statements. These forward-looking statements include, without limitation, statements regarding the therapeutic potential and safety profile of our product candidates, including, based on early data, PGN-EDO51 and PGN-EDODM1, the potential of our EDO platform to deliver higher levels of oligonucleotide to the nuclei, the design, initiation and conduct of clinical trials, including expected timelines for our CONNECT1 and CONNECT2 Phase 2 trials, our FREEDOM Phase 1 trial and our FREEDOM2 Phase 2 trial, the expected timing for additional data reports from our CONNECT1 Phase 2 trial, and our FREEDOM Phase 1 trial, ongoing and planned regulatory interactions, and our financial resources and expected cash runway.

Any forward-looking statements in this press release are based on current expectations, estimates and projections only as of the date of this release and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such

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forward-looking statements. These risks and uncertainties include, but are not limited to risks related to: delays or failure to successfully initiate or complete our ongoing and planned development activities for our product candidates, including PGN-EDO51 and PGN-EDODM1; our ability to enroll patients in our clinical trials, including CONNECT1, CONNECT2, FREEDOM and FREEDOM2; that our interpretation of clinical and preclinical study results may be incorrect, or that we may not observe the levels of therapeutic activity in clinical testing that we anticipate based on prior clinical or preclinical results, including for PGN-EDO51 and PGN-EDODM1; our product candidates, including PGN-EDO51 and PGN-EDODM1, may not be safe and effective or otherwise demonstrate safety and efficacy in our clinical trials; adverse outcomes from our regulatory interactions, including delays in regulatory review, clearance to proceed or approval by regulatory authorities with respect to our programs, including clearance to commence planned clinical studies of our product candidates, or other regulatory feedback requiring modifications to our development programs, including in each case with respect to our CONNECT1, CONNECT2, FREEDOM and FREEDOM2 clinical trials; changes in regulatory framework that are out of our control; unexpected increases in the expenses associated with our development activities or other events that adversely impact our financial resources and cash runway; and our dependence on third parties for some or all aspects of our product manufacturing, research and preclinical and clinical testing. Additional risks concerning PepGen’s programs and operations are described in our most recent annual report on Form 10-K and quarterly report on Form 10-Q that are filed with the SEC. PepGen explicitly disclaims any obligation to update any forward-looking statements except to the extent required by law.

This release discusses PGN-EDO51 and PGN-EDODM1, investigational therapies that have not been approved for use in any country and is not intended to convey conclusions about their efficacy or safety. There is no guarantee that PGN-EDO51, PGN-EDODM1 or any other investigational therapy will successfully complete clinical development or gain regulatory authority approval.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Condensed Consolidated Statements of Operations

(unaudited, in thousands)

	Twelve Months Ended December 31,				Three Months Ended  December 31,
	2024		2023		2024		2023
Operating expenses:
Research and development	$ 76,478		$68,126		$18,961		$ 16,300
General and administrative	21,261		16,640		5,384		4,511
Total operating expenses	$ 97,739		$84,766		$24,345		$ 20,811
Operating loss	$(97,379)		$(84,766)		$(24,345)		$(20,811)
Other income (expense)
Interest income	7,142		6,400		1,460		1,346
Other income (expense), net	(1)		(187)		26		43
Total other income, net	7,141		6,213		1,486		1,389
Net loss before income tax	$(90,598)		$(78,553)		$(22,859)		$(19,422)
Income tax (expense) benefit	617		(73)		617		(73)
Net loss	$(89,981)		$(78,626)		$(22,242)		$(19,495)
Net loss per share, basic and diluted	$(2.85)		$(3.30)		$(0.68)		$(0.82)
Weighted-average common shares outstanding, basic and diluted	31,583,073		23,796,000		32,602,981		23,816,919

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Condensed Consolidated Balance Sheets

(unaudited, in thousands)

	December 31,		December 31,
	2024		2023
Assets
Cash, cash equivalents and marketable securities	$ 120,191		$ 110,407
Other assets	30,692		32,645
Total assets	$ 150,883		$ 143,052
Liabilities and stockholders’ equity
Liabilities	$ 32,263		$ 34,631
Stockholders’ equity	118,620		108,421
Total liabilities and stockholders’ equity	$ 150,883		$ 143,052

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Investor Contact
Dave Borah, CFA

SVP, Investor Relations and Corporate Communications

dborah@pepgen.com

Media Contact

Julia Deutsch

Lyra Strategic Advisory

Jdeutsch@lyraadvisory.com

 

 

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PepGen Announces Positive Initial Results, Including Robust Splicing Correction, from Ongoing FREEDOM-DM1 Trial in Patients with DM1

 

– Significant mean splicing correction of 29.1% following a single dose of PGN-EDODM1 at 10 mg/kg –

 

– PGN-EDODM1 observed to have favorable emerging safety profile –

 

– Conference call scheduled today at 8:00 a.m. ET –

 

BOSTON, February 24, 2025 -- PepGen Inc. (Nasdaq: PEPG), a clinical-stage biotechnology company advancing the next generation of oligonucleotide therapies with the goal of transforming the treatment of severe neuromuscular and neurological diseases, today announced initial positive clinical data from the 5 and 10 mg/kg dose cohorts in the ongoing FREEDOM-DM1 Phase 1 trial investigating PGN-EDODM1 in myotonic dystrophy type 1 (DM1).

“These results far exceeded our expectations for splicing correction following a single dose of PGN-EDODM1. Mis-splicing is the underlying cause of DM1 pathology, and we believe the mean splicing correction observed at 28 days following a single dose of PGN-EDODM1 at 10 mg/kg in the FREEDOM clinical trial surpasses those reported to date in multi-dose clinical trials of up to nine months in duration in patients with DM1. We believe this is a strong indicator of our EDO technology’s potential to deliver therapeutic oligonucleotides to the nucleus and PGN-EDODM1’s potential to address the underlying cause of disease,” said James McArthur, PhD, President and CEO of PepGen. “We believe these results provide initial validation of PGN-EDODM1's ability to selectively bind the pathogenic CUG-repeat DMPK RNA and we look forward to evaluating PGN-EDODM1 with more doses over longer time periods in our FREEDOM2-DM1 multiple ascending dose study. Based on these initial results, we aim to build on the significant correction of mis-splicing observed in this single-dose study to potentially provide improved functional benefit for patients who currently have no available approved therapeutic options.”

 

FREEDOM Results for the 5 mg/kg (n=8) and 10 mg/kg (n=8) Dose Cohorts

 

Splicing, Muscle Tissue Concentration and Functional Data:

 

 

 

 

 

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Safety and Tolerability Data:

 

 

“These initial results from the FREEDOM clinical trial are highly encouraging. The emerging safety profile is very promising. The dose-dependent splicing correction may suggest that the drug gets into the muscle and effectively binds to the target. Mis-splicing is central to the cause of DM1, and correcting mis-splicing may improve functional outcomes for DM1 patients over time. With this in mind, I am particularly excited by the levels of splicing correction seen after only a single dose of PGN-EDODM1. Based on previous work, I believe that these effects could be stronger as levels of the drug build up with repeat dosing,” said Dr. Johanna Hamel, Associate Professor of Neurology, Pathology and Laboratory Medicine at the University of Rochester Medical Center.

 

The Company expects to report results from the FREEDOM 15 mg/kg cohort in the second half of 2025 and from the FREEDOM2 5 mg/kg cohort in the first quarter of 2026.

 

Conference Call Details

PepGen will host a conference call and webcast today at 8:00 a.m. ET to review the FREEDOM data. To access the call, please dial (800) 218-2154 and provide the Conference ID 8807881. A live webcast of the presentation will be available on the Events & Presentations section of the PepGen investor website, investors.pepgen.com.

 

About PGN-EDODM1

PGN-EDODM1, PepGen's investigational candidate in development for the treatment of DM1, utilizes the Company's proprietary EDO technology to deliver a therapeutic oligonucleotide that is designed to restore the normal splicing function of MBNL1, a key RNA splicing protein. PGN-EDODM1 is designed to directly address the deleterious effects of cytosine-uracil-guanine (CUG) repeat expansion in the dystrophia myotonica protein kinase (DMPK) transcripts which sequester MBNL1, by binding to the pathogenic CUG trinucleotide repeat expansion present in the DMPK transcripts, disrupting the binding between the CUG repeat expansion and MBNL1. We believe this mechanism will allow the DMPK transcripts to continue performing their normal function within the cell, while also liberating MBNL1 to correct downstream mis-splicing events. We believe that this innovative therapeutic approach has considerable advantages over oligonucleotide modalities that rely on knockdown or degradation of the DMPK transcripts. The U.S. Food and Drug Administration has granted PGN-EDODM1 both Orphan Drug and Fast Track Designations for the treatment of patients with DM1.

 

About the FREEDOM Clinical Program

FREEDOM-DM1 is a multinational, randomized, double-blind, placebo-controlled Phase 1 single ascending dose study, enrolling up to approximately 32 adult participants with DM1 in multiple geographies including the United States, the United Kingdom and Canada, to evaluate the safety and tolerability of PGN-EDODM1. Per the protocol, PGN-EDODM1 was administered at starting doses of 5 mg/kg and 10 mg/kg with subsequent dose escalation to 15 mg/kg, and potentially in the future to 20

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mg/kg, based upon evaluation by a safety committee of safety data from the prior dose cohort(s). Muscle biopsies are being conducted at baseline, at day 28 and at week 16. In addition to safety and tolerability, oligonucleotide muscle concentrations, splicing correction and functional outcome measures are being assessed at day 28 and at week 16 following a single dose of PGN-EDODM1.

 

FREEDOM2-DM1 is a Phase 2 randomized, double-blind, placebo-controlled, multiple ascending dose clinical trial evaluating PGN-EDODM1 in approximately 24 adult participants with DM1 in Canada, the United Kingdom, and potentially other geographies, including the United States, subject to regulatory clearances.

 

About Myotonic Dystrophy Type 1

Myotonic dystrophy type 1 is a monogenic, autosomal dominant, progressive disorder that primarily affects skeletal, cardiac and smooth muscles, with central nervous system symptoms also being evident. Globally, the prevalence of DM1 is estimated to be 1 in 8,000 people, with approximately 40,000 patients in the United States, 75,000 patients in Europe and 15,000 patients in Japan.

 

DM1 patients can suffer from various manifestations of disease including myotonia, or a temporary rigidity due to the inability to relax muscles, muscle weakness, cardiac abnormalities, respiratory problems, fatigue, gastrointestinal complications, early cataracts, and cognitive and behavioral impairments. For patients with more severe forms of DM1, life expectancy is reduced due to increased mortality rates resulting from pulmonary and cardiac complications.

 

About PepGen

PepGen Inc. is a clinical-stage biotechnology company advancing the next generation of oligonucleotide therapies with the goal of transforming the treatment of severe neuromuscular and neurological diseases. PepGen’s Enhanced Delivery Oligonucleotide (EDO) platform is founded on over a decade of research and development and leverages cell-penetrating peptides to improve the uptake and activity of conjugated oligonucleotide therapeutics. Using these EDO peptides, we are generating a pipeline of oligonucleotide therapeutic candidates designed to target the root cause of serious diseases.

For more information, please visit www.pepgen.com. Follow PepGen on LinkedIn and X.

 

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “intends,” “may,” “plans,” “possible,” “potential,” “seeks,” “will,” and variations of these words or similar expressions that are intended to identify forward-looking statements. Any such statements in this press release that are not statements of historical fact may be deemed to be forward-looking statements. These forward-looking statements include, without limitation, statements regarding the therapeutic potential and safety profile of PGN-EDODM1, including as it relates to data from the 5 and 10 mg/kg cohorts of the FREEDOM-DM1 study, the potential of our EDO platform to deliver higher levels of oligonucleotide to the nuclei, our expectations regarding the potential for significant correction of mis-splicing with more doses of PGN-EDODM1 over a longer treatment period to potentially provide improved functional benefit for patients with DM1, the expected timing for additional data reports from our FREEDOM trial and the initial data report from our FREEDOM2-DM1 trial, any functional improvements that may result from robust splicing correction with PGN-EDODM1, dose-dependent increases in splicing suggesting that PGN-EDODM1 is getting into the muscle and effectively binding to the target, and ongoing and planned regulatory interactions.

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Any forward-looking statements in this press release are based on current expectations, estimates and projections only as of the date of this release and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to risks related to: delays or failure to successfully initiate or complete our ongoing and planned development activities for our product candidates, including PGN-EDODM1; our ability to enroll patients in our clinical trials, including FREEDOM and FREEDOM2; that our interpretation of clinical and preclinical study results may be incorrect, or that we may not observe the levels of therapeutic activity in clinical testing that we anticipate based on prior clinical or preclinical results; our product candidates, including PGN-EDODM1, may not be safe and effective or otherwise demonstrate safety and efficacy in our clinical trials; adverse outcomes from our regulatory interactions, including delays in regulatory review, clearance to proceed or approval by regulatory authorities with respect to our programs, including clearance to commence planned clinical studies of our product candidates, or other regulatory feedback requiring modifications to our development programs, including in each case with respect to our FREEDOM and FREEDOM2 programs; changes in regulatory framework that are out of our control; unexpected increases in the expenses associated with our development activities or other events that adversely impact our financial resources and cash runway; and our dependence on third parties for some or all aspects of our product manufacturing, research and preclinical and clinical testing. Additional risks concerning PepGen’s programs and operations are described in our most recent annual report on Form 10-K that is filed with the SEC. PepGen explicitly disclaims any obligation to update any forward-looking statements except to the extent required by law.

 

This release discusses PGN-EDODM1, an investigational therapy that has not been approved for use in any country, and is not intended to convey conclusions about its efficacy or safety. There is no guarantee that PGN-EDODM1 or any other investigational therapy will successfully complete clinical development or gain regulatory authority approval.

 

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Investor Contact
Dave Borah, CFA

SVP, Investor Relations and Corporate Communications

dborah@pepgen.com

Media Contact

Julia Deutsch

Lyra Strategic Advisory

Jdeutsch@lyraadvisory.com

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February 24, 2025 FREEDOM-DM1 5 and 10 mg/kg Clinical Data Update

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Forward-Looking Statements This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “intends,” “may,” “plans,” “possible,” “potential,” “seeks,” “will,” and variations of these words or similar expressions that are intended to identify forward-looking statements. Any such statements in this presentation that are not statements of historical fact may be deemed to be forward-looking statements. These forward-looking statements include, without limitation, statements regarding the potential of our EDO platform to deliver higher levels of oligonucleotide to the nuclei, the therapeutic potential and safety profile of PGN-EDODM1 based on data from the 5 and 10 mg/kg cohorts of the FREEDOM-DM1 study, our expectations regarding the potential for significant correction of mis-splicing with more doses of PGN-EDODM1 over a longer treatment period to potentially provide improved functional benefit for patients with DM1, the design, initiation and conduct of clinical trials, including expected timelines for our FREEDOM1-DM1 Phase 1 and FREEDOM2-DM1 Phase 2 trials and our CONNECT1-EDO51 and CONNECT2-EDO51 Phase 2 trials, the expected timing for additional data reports from our FREEDOM Phase 1 trial and CONNECT1 Phase 2 trial, and ongoing and planned regulatory interactions. Any forward-looking statements in this presentation are based on current expectations, estimates and projections only as of the date of this presentation and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: delays or failure to successfully initiate or complete our ongoing and planned development activities for our product candidates, including PGN-EDODM1 and PGN-EDO51; our ability to enroll patients in our clinical trials, including FREEDOM, FREEDOM2, CONNECT1 and CONNECT2; that our interpretation of clinical and preclinical study results may be incorrect, or that we may not observe the levels of therapeutic activity in clinical testing that we anticipate based on prior clinical or preclinical results, including for PGN-EDODM1 and PGN-EDO51; our product candidates, including PGN-EDODM1 and PGN-EDO51, may not be safe and effective or otherwise demonstrate safety and efficacy in our clinical trials; adverse outcomes from our regulatory interactions, including delays in regulatory review, clearance to proceed or approval by regulatory authorities with respect to our programs, including clearance to commence planned clinical studies of our product candidates, or other regulatory feedback requiring modifications to our development programs, including in each case with respect to our including FREEDOM, FREEDOM2, CONNECT1 and CONNECT2 clinical trials; changes in regulatory framework that are out of our control; our ability to obtain, maintain and protect our intellectual property; our ability to enforce our patents against infringers and defend our patent portfolio against challenges from third parties; competition from others developing therapies for the indications we are pursuing; unexpected increases in the expenses associated with our development activities or other events that adversely impact our financial resources and cash runway; and our dependence on third parties for some or all aspects of our product manufacturing, research and preclinical and clinical testing. Additional risks concerning PepGen's programs and operations are described in our most recent annual report on Form 10-K that is filed with the SEC. PepGen explicitly disclaims any obligation to update any forward-looking statements except to the extent required by law. This presentation discusses PGN-EDODM1 and PGN-EDO51, investigational therapies that have not been approved for use in any country, and is not intended to convey conclusions about their efficacy or safety. There is no guarantee that PGN-EDODM1, PGN-EDO51 or any other investigational therapy will successfully complete clinical development or gain regulatory authority approval.

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Agenda Paul Streck, MD, MBA Head of R&D FREEDOM Clinical Trial Design, Clinical Data, and Q&A James McArthur, PhD President and Chief Executive Officer Key Takeaways, DM1 Overview, EDO Platform, Closing Remarks, and Q&A Michelle Mellion, MD Chief Medical Officer Q&A

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PGN-EDODM1 Initial Data FREEDOM-DM1 Study:Myotonic Dystrophy Type I Overview and EDO Platform James McArthur, PhD President and Chief Executive Officer

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PGN-EDODM1 Has Demonstrated Robust Dose-Dependent Splicing Correction Following Single Dose in First Two Cohorts As of data cut-off date Dec 3, 2024 Favorable emerging safety profile in patients with myotonic dystrophy type 1 (DM1)1 Robust splicing correction at Day 28 Dose-dependent increases in drug tissue concentration and mean splicing correction were observed in first two cohorts Mis-splicing is the known cause of DM1, and we believe that with repeat and higher dosing, PGN-EDODM1 has the potential to produce greater splicing correction levels, which could lead to improved functional outcomes for patients

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Myotonic Dystrophy Type 1 Overview and Unmet Medical Need Sources: Neuroepidemiology (2022) 56 (3): 163–173., Neurology 2021 Feb 16;96(7):e1045-e1053 CUG: cytosine-uracil-guanine; DMPK: dystrophia myotonica protein kinase Overview Market Opportunity CUG expansion in the DMPK gene Onset of symptoms variable- childhood to adulthood Myotonia Muscle weakness Cardiac arrythmias Loss of lung function Fatigue Average life expectancy is 50-60 years for non-congenital forms of DM1 U.S and EU over 110,000 patients No approved therapies that address underlying cause of the disease Jubal, retired professor living with DM1

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DM1 Patient Unaffected Individual Mis-Splicing is the Underlying Cause of DM1​ Lopez-Martinez, et al., An Overview of Alternative Splicing Defects Implicated in Myotonic Dystrophy Type 1, Genes, September 2020 Sznajder & Swanson, Short Tandem Repeat Expansions and RNA-Mediated Pathogenesis in Myotonic Dystrophy, International Journal of Molecular Sciences, July 2019

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DM1 is Caused by Pathogenic CUG Repeats in DMPK RNA DM1 is caused by pathogenic DMPK transcripts Approximately 50% of DMPK transcripts are pathogenic while the remaining DMPK transcripts are normal1 Pathogenic DMPK transcripts containing cytosine-uracil-guanine (CUG) repeat sequences form hairpin loops These hairpin loops trap MBNL1 proteins MBNL1 is a splicing factor required for processing multiple RNAs into proteins accurately Bound MBNL1 (inactive) DMPK transcript Trapped MBNL1 is inactive and results in mis-splicing Wojciechowska, et al., Quantitative Methods to Monitor RNA Biomarkers in Myotonic Dystrophy, Nature, April 12, 2018

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PGN-EDODM1 Blocking Approach Targets Only the Pathogenic DMPK RNA PGN-EDODM1 is engineered to bind selectively to the pathogenic CUG repeat expansion present in DMPK transcript This reduces the ability of these CUG repeats to form hairpin loops and sequester RNA splicing proteins, including MBNL1, in the nucleus Bound MBNL1 (inactive) Free MBNL1 (active) PGN-EDODM1 PGN-EDODM1 binds selectively to the pathogenic DMPK transcript Liberated MBNL1 restores correct splicing

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Immortalized myoblasts from a healthy individual or a DM1 patient with 2600 CTG repeats were cultured then differentiated for 4 days into myotubes and then treated with fluorescently tagged PGN-PMODM1 (PMO) or PGN-EDODM1 (PPMO) at concentrations detailed above. Cells were visualized by confocal microscopy 24h after treatment. Not treated 0 µM PGN-PMODM1 20 µM PGN-EDODM1 / Actin / Nucleus Enhanced Delivery Oligonucleotide (EDO) Platform Enhances Nuclear Delivery and Uptake of Oligonucleotides Naked oligonucleotides not efficiently taken up into muscle cells & nucleus EDOs enhance nuclear delivery of oligonucleotide therapeutics PGN-EDODM1 2 µM 10 µM

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FREEDOM-DM1 Trial Design and Clinical Data Paul Streck, MD, MBA Head of R&D

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FREEDOM: Phase 1 PGN-EDODM1 Single-Ascending Dose Study Design 1.15 mg/kg cohort added to expand pharmacokinetic and pharmacodynamic understandingDSMB: data safety monitoring board; IV: intravenous; PBO: placebo; SAD: single-ascending dose; PK: pharmacokinetics PGN-EDODM1 dose FREEDOM Study Overview Multinational, randomized,double-blind, placebo-controlled SAD study in patients Single IV administration ofPGN-EDODM1 Muscle biopsies in tibialis anteriorat Baseline, Day 28, Week 16 Safety, PK, correction of mis-splicing, initial functional assessments Single Dose PGN-EDODM1 or Placebo (randomized 3:1) 15 mg/kgor PBO1 Baseline DSMB Wk 16 D28 Biopsy Biopsy Biopsy 10 mg/kgor PBO Baseline DSMB Wk 16 D28 Biopsy Biopsy Biopsy 5 mg/kgor PBO Baseline DSMB Wk 16 D28 Biopsy Biopsy Biopsy 20 mg/kgor PBO Baseline DSMB Wk 16 D28 Biopsy Biopsy Biopsy Dosed n=8 n=8 n=8 n=8 Dosing

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FREEDOM: Demographics and Baseline Characteristics in First Two Cohorts *n=5 as one participant’s sample showed splicing index outside the pre-specified assay range at Baseline (no detectable mis-splicing) Splicing Index (SI) Mild = 0–0.4, SI Moderate = 0.41–0.75, and SI Severe = 0.76–1.0. Provenzano, et al. SD: standard deviation; BMI: body mass index; PBO: placebo; vHOT: video hand opening time; 10MWRT: 10-meter walk run test Mean (SD) or n (%) Placebo (n=4) 5 mg/kg (n=6) 10 mg/kg (n=6) Age (years) 39.0 (10.9) 36.3 (9.0)​ 34.7 (8.2)​ Female, n (%) 3 (75%) 3 (50%)​ 3 (50%)​ BMI (kg/m2) 20.0 (3.3) 22.8 (5.0)​ 22.8 (5.7)​ Splicing Index 72.3 (16.3) 73.7 (15.2) 53.6* (26.0) vHOT – middle finger (sec) 14.1 (5.6) 12.6 (7.3) 9.3 (2.8) 10MWRT (sec) 4.3 (1.6) 3.9 (1.5) 4.4 (1.5)

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Favorable Emerging Safety Profile of PGN-EDODM11 As of December 3, 2024 Includes all participants (placebo and PGN-EDODM1 treated); cohorts remain blinded Data Safety Monitoring Board reviewed event and recommended continuation of study/dosing SAE: serious adverse event; AESI: adverse event of special interest 5 mg/kg (n=8)2 n(%) 10 mg/kg (n=8)2 n(%) Total (n=16)2 n(%) Any TEAE 4 (50.0) 6 (75.0) 10 (62.5) Any related TEAE 1 (12.5) 3 (37.5) 4 (25.0) Any SAE 1 (12.5) 2 (25.0) 3 (18.8) Any related SAE 0 1 (12.5) 1 (6.3) Any AESI or dose-limiting toxicities 0 0 0 Any TEAE leading to study withdrawal 0 0 0 Any TEAE leading to death 0 0 0 All treatment related TEAEs: Nausea (n=2), vomiting (n=1), dizziness (n=1), headache (n=1), feeling hot (n=1), abdominal pain (n=1) SAE related to study drug: Abdominal pain (10 mg/kg) potentially confounded by use of prohibited, off-label drug taken on the morning of PGN-EDODM1 dosing3 SAEs unrelated to study drug: Appendicitis (5 mg/kg) Right anterior tibial artery pseudoaneurysm (10 mg/kg) in connection with biopsy procedure No adverse events related to electrolytes or renal biomarkers Summary of Treatment Emergent Adverse Events (TEAEs) PGN-EDODM1 was Generally Well-Tolerated, with Most TEAEs Mild or Moderate in Severity

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PGN-EDODM1 Demonstrated Normal Mean Serum Creatinine Levels *   Serum Creatinine 1. Includes all participants (placebo and PGN-EDODM1 treated); cohorts remain blinded BL: baseline; ULN: upper limit of normal; M: male; F: female All participants in both cohorts remained below ULN 1 1

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PGN-EDODM1 Observed to Have Robust and Dose-Dependent Increase in Muscle Tissue Concentration Following Single Dose 1. One participant’s biopsy was not collected at Day 28 due to pseudoaneurysm in connection with biopsy procedure SEM: standard error of the mean; Placebo tissue concentration was below level of quantification * Muscle Tissue Concentration at D28 44.1 13.7 (n=5)1

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PGN-EDODM1 Produced Mean 29% Splicing Correction Following Single 10 mg/kg Dose Splicing Index Changes: 22-Gene Panel1 at D28 Improvement Provenzano et al., The Splice Index as a prognostic biomarker of strength and function in myotonic dystrophy type 1, J Clin. Invest. 2025 In 10 mg/kg cohort: One participant’s biopsy was not collected at Day 28 due to pseudoaneurysm in connection with biopsy procedure and one participant’s sample showed splicing index outside the pre-specified assay range at Baseline and Day 28 (no detectable mis-splicing) and was excluded from the analysis. 7.5 -12.3 -29.1 5 / 6 splicing correction 3 / 4 splicing correction

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Functional Outcome Data After Single Dose vHOT: video hand opening time 10-Meter Walk Run Test (10MWRT) at D28 Myotonia (vHOT) at D28 -0.35 Improvement Improvement

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Closing Remarks James McArthur, PhD President and Chief Executive Officer

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PGN-EDODM1 Selectively Targets Only Pathogenic DMPK to Correct RNA Mis-Splicing As of data cut-off date Dec 3, 2024 Two participants in the 10 mg/kg cohort were excluded from the splicing correction assay. One participant’s biopsy was not collected at Day 28 and the other participant’s splicing index values were outside of the pre-specified assay range, both at Baseline and at Day 28. Favorable emerging safety profile1 in patients with myotonic dystrophy type 1 Dose-dependent increases in evaluable patients2 in mean splicing correction following single dose Dose-dependent increase in drug tissue concentration observed in first two cohorts ~12% at 5 mg/kg ~29% at 10 mg/kg

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FREEDOM2 Phase 2 MAD Study Underway DSMB: data safety monitoring board; FU: follow-up; IV: intravenous; MAD: multiple-ascending dose; PBO: placebo; PK: pharmacokinetics; vHOT: video hand opening test PGN-EDODM1 dose every 4 weeks FREEDOM2 Study Overview Multinational, randomized, double-blind, placebo-controlled, MAD study open in UK and Canada IV administration of PGN-EDODM1 or placebo every 4 weeks for a period of 12 weeks Key endpoints: Safety, PK, correction of splicing, functional assessments: vHOT, hand grip, 10-meter walk run test 4 Doses of PGN-EDODM1 or Placebo (randomized 3:1) Safety FU Biopsy Biopsy 20 mg/kg or PBO DSMB Safety FU Biopsy Biopsy 10 mg/kg or PBO DSMB Biopsy Biopsy 5 mg/kg or PBO DSMB n=8 n=8 n=8 Safety FU Dosing

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Key Anticipated Milestones Ahead Key Expected Data Readouts/ Milestones 2H 2025: FREEDOM 15 mg/kg clinical results Q1 2026: FREEDOM2 5 mg/kg clinical results Q3 2025: CONNECT1 10 mg/kg clinical results

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Question and Answer Session Paul Streck, MD, MBA Head of R&D James McArthur, PhD President and Chief Executive Officer Michelle Mellion, MD Chief Medical Officer

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24 Communityand clinicaladvisors Clinical studyparticipants andtheir families Thank you! Clinical site staff and investigators Preclinical collaborators

v3.25.0.1

Document And Entity Information	Feb. 24, 2025
Cover [Abstract]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Feb. 24, 2025
Entity Registrant Name	PepGen Inc.
Entity Central Index Key	0001835597
Entity Emerging Growth Company	true
Entity File Number	001-41374
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-3819886
Entity Address, Address Line One	321 Harrison Avenue
Entity Address, Address Line Two	8th Floor
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02118
City Area Code	(781)
Local Phone Number	797-0979
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
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

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