[SCHEDULE 13G] PepGen Inc. SEC Filing

Rhea-AI Filing Summary

PepGen Inc.'s Schedule 13G shows that a group of Viking Global entities and three named executives report beneficial ownership of 3,482,434 shares of PepGen common stock, representing 5.1% of the 68,737,224 shares outstanding following the issuer's underwritten offering that closed on September 26, 2025. The filing states the shares are directly owned by Viking Global Opportunities Illiquid Investments Sub-Master LP and are subject to shared voting and shared dispositive power among the reporting persons. The filing includes a joint filing agreement and certifications that the holdings were not acquired to change or influence control.

Insights

Institutional Ownership Analyst

Viking Global and related entities hold a 5.1% stake (3,482,434 shares) in PepGen.

The filing attributes the economic ownership to Viking Global Opportunities Illiquid Investments Sub-Master LP while multiple affiliated entities and three executives report shared voting and dispositive power over the 3,482,434 shares.

This is a passive Schedule 13G disclosure indicating a significant minority stake post-offering; the signatories certify the position is not held to influence control.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

PepGen Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

713317105

(CUSIP Number)

09/26/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

VIKING GLOBAL INVESTORS LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Viking Global Opportunities Parent GP LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Viking Global Opportunities GP LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Viking Global Opportunities Portfolio GP LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Viking Global Opportunities Illiquid Investments Sub-Master LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

HALVORSEN OLE ANDREAS

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

NORWAY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Ott David C.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

CUSIP No. 713317105

1

Names of Reporting Persons

Shabet Rose Sharon

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,482,434.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,482,434.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,482,434.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.1 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: See Item 4

SCHEDULE 13G

Item 1.
(a)	Name of issuer: PepGen Inc.
(b)	Address of issuer's principal executive offices: 321 Harrison Avenue, 8th Floor, Boston, Massachusetts, 02118
Item 2.
(a)	Name of person filing: Viking Global Investors LP ("VGI"), Viking Global Opportunities Parent GP LLC ("Opportunities Parent"), Viking Global Opportunities GP LLC ("Opportunities GP"), Viking Global Opportunities Portfolio GP LLC ("Opportunities Portfolio GP"), Viking Global Opportunities Illiquid Investments Sub-Master LP ("VGOP"), O. Andreas Halvorsen, David C. Ott and Rose S. Shabet (collectively, the "Reporting Persons")
(b)	Address or principal business office or, if none, residence: The business address of each of the Reporting Persons is: 600 Washington Boulevard, Floor 11, Stamford, Connecticut 06901.
(c)	Citizenship: VGI is a Delaware limited partnership; Opportunities Parent, Opportunities GP and Opportunities Portfolio GP are Delaware limited liability companies; VGOP is a Cayman Islands exempted limited partnership; O. Andreas Halvorsen is a citizen of Norway; and David C. Ott and Rose S. Shabet are citizens of the United States.
(d)	Title of class of securities: Common Stock, par value $0.0001 per share
(e)	CUSIP No.: 713317105
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: VGI: 3,482,434 VGI provides managerial services to VGOP. VGI has the authority to dispose of and vote the shares of Common Stock. Based on Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Act"), VGI may be deemed to beneficially own the shares of Common Stock directly held by VGOP. VGI does not directly own any shares of Common Stock. VGI beneficially owns 3,482,434 shares of Common Stock consisting of 3,482,434 shares of Common Stock directly and beneficially owned by VGOP. Opportunities Parent: 3,482,434 Opportunities Parent is the sole member of Opportunities GP, which has the authority to dispose of and vote the shares of Common Stock controlled by Opportunities Portfolio GP, which consists of the shares of Common Stock directly held by VGOP. Opportunities Parent does not directly own any shares of Common Stock. Based on Rule 13d-3 under the Act, Opportunities Parent may be deemed to beneficially own the shares of Common Stock directly held by VGOP. Opportunities Parent beneficially owns 3,482,434 shares of Common Stock consisting of 3,482,434 shares of Common Stock directly owned by VGOP. Opportunities GP: 3,482,434 Opportunities GP serves as the sole member of Opportunities Portfolio GP and has the authority to dispose of and vote the shares of Common Stock controlled by Opportunities Portfolio GP, which consists of the shares of Common Stock directly held by VGOP. Opportunities GP does not directly own any shares of Common Stock. Based on Rule 13d-3 under the Act, Opportunities GP may be deemed to beneficially own the shares of Common Stock directly held by VGOP. Opportunities GP beneficially owns 3,482,434 shares of Common Stock consisting of 3,482,434 shares of Common Stock directly owned by VGOP. Opportunities Portfolio GP: 3,482,434 Opportunities Portfolio GP serves as the general partner of VGOP and has the authority to dispose of and vote the shares of Common Stock directly owned by VGOP. Opportunities Portfolio GP does not directly own any shares of Common Stock. Based on Rule 13d-3 under the Act, Opportunities Portfolio GP may be deemed to beneficially own the shares of Common Stock directly held by VGOP. Opportunities Portfolio GP beneficially owns 3,482,434 shares of Common Stock consisting of 3,482,434 shares of Common Stock directly owned by VGOP. VGOP: 3,482,434 VGOP has the authority to dispose of and vote the 3,482,434 shares of Common Stock directly owned by it, which power may be exercised by its general partner, Opportunities Portfolio GP, and by VGI, an affiliate of Opportunities Portfolio GP, which provides managerial services to VGOP. Viking Global Opportunities LP (a Delaware limited partnership) and Viking Global Opportunities III LP (a Cayman Islands exempted limited partnership), through its investment in Viking Global Opportunities Intermediate LP (a Cayman Islands exempted limited partnership), invest substantially all of their assets in Viking Global Opportunities Master LP (a Cayman Islands exempted limited partnership), which in turn invests through VGOP. O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 3,482,434 Mr. Halvorsen, Mr. Ott and Ms. Shabet, as Executive Committee Members of Viking Global Partners LLC (general partner of VGI) and Opportunities Parent, have shared authority to dispose of and vote the shares of Common Stock beneficially owned by VGI and Opportunities Parent. None of Mr. Halvorsen, Mr. Ott and Ms. Shabet directly owns any shares of Common Stock. Based on Rule 13d-3 under the Act, each may be deemed to beneficially own the shares of Common Stock directly held by VGOP. Mr. Halvorsen, Mr. Ott and Ms. Shabet each beneficially own 3,482,434 shares of Common Stock consisting of 3,482,434 shares of Common Stock directly owned by VGOP.
(b)	Percent of class: The percentages set forth herein are based on 68,737,224 shares of Common Stock outstanding following the Issuer's underwritten offering that closed on September 26, 2025, and after the underwriters exercised their option to purchase additional shares of Common Stock in full, as reported in the Issuer's prospectus on Form 424B5, filed with the Securities and Exchange Commission (the "Commission") on September 25, 2025, and the Issuer's current report on Form 8-K, filed with the Commission on September 26, 2025. VGI: 5.1% Opportunities Parent: 5.1% Opportunities GP: 5.1% Opportunities Portfolio GP: 5.1% VGOP: 5.1% O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 5.1%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: VGI: 0 Opportunities Parent: 0 Opportunities GP: 0 Opportunities Portfolio GP: 0 VGOP: 0 O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 0
	(ii) Shared power to vote or to direct the vote: VGI: 3,482,434 Opportunities Parent: 3,482,434 Opportunities GP: 3,482,434 Opportunities Portfolio GP: 3,482,434 VGOP: 3,482,434 O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 3,482,434
	(iii) Sole power to dispose or to direct the disposition of: VGI: 0 Opportunities Parent: 0 Opportunities GP: 0 Opportunities Portfolio GP: 0 VGOP: 0 O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 0
	(iv) Shared power to dispose or to direct the disposition of: VGI: 3,482,434 Opportunities Parent: 3,482,434 Opportunities GP: 3,482,434 Opportunities Portfolio GP: 3,482,434 VGOP: 3,482,434 O. Andreas Halvorsen, David C. Ott and Rose S. Shabet: 3,482,434
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The response to Item 4 is incorporated by reference herein.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

VIKING GLOBAL INVESTORS LP

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of VIKING GLOBAL INVESTORS LP (1)(2)(3)
Date:	10/03/2025

Viking Global Opportunities Parent GP LLC

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of Viking Global Opportunities Parent GP LLC (1)(2)(3)
Date:	10/03/2025

Viking Global Opportunities GP LLC

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of Viking Global Opportunities GP LLC (1)(2)(3)
Date:	10/03/2025

Viking Global Opportunities Portfolio GP LLC

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of Viking Global Opportunities Portfolio GP LLC (1)(2)(3)
Date:	10/03/2025

Viking Global Opportunities Illiquid Investments Sub-Master LP

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of Viking Global Opportunities Illiquid Investments Sub-Master LP (1)(2)(3)
Date:	10/03/2025

HALVORSEN OLE ANDREAS

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of O. Andreas Halvorsen (1)
Date:	10/03/2025

Ott David C.

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of David C. Ott (2)
Date:	10/03/2025

Shabet Rose Sharon

Signature:	/s/ Scott M. Hendler
Name/Title:	Scott M. Hendler on behalf of Rose S. Shabet (3)
Date:	10/03/2025

Comments accompanying signature: (1) Scott M. Hendler is signing on behalf of O. Andreas Halvorsen, individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES PARENT GP LLC, on behalf of itself and VIKING GLOBAL OPPORTUNITIES GP LLC, VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC, and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP, pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the Commission as an exhibit to a Form 13G filed by Mr. Halvorsen on February 12, 2021 (SEC File No. 005-49737). (2) Scott M. Hendler is signing on behalf of David C. Ott, individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES PARENT GP LLC, on behalf of itself and VIKING GLOBAL OPPORTUNITIES GP LLC, VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC, and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP, pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the Commission as an exhibit to a Form 13G filed by Mr. Ott on February 12, 2021 (SEC File No. 005-49737). (3) Scott M. Hendler is signing on behalf of Rose S. Shabet, individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES PARENT GP LLC, on behalf of itself and VIKING GLOBAL OPPORTUNITIES GP LLC, VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC, and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP, pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the Commission as an exhibit to a Form 13G filed by Ms. Shabet on February 12, 2021 (SEC File No. 005-49737).

Exhibit Information

EXHIBIT A - JOINT FILING AGREEMENT