GV 2021 GP, L.L.C. - 01 Aug 2025 Form 4 Insider Report for Prime Medicine, Inc. (PRME)

Role: 10%+ Owner
Signature: /s/ Inga Goldbard, General Counsel of GV 2021 GP, L.L.C.
Issuer symbol: PRME
Transactions as of: 01 Aug 2025
Net transactions value: +$4,950,000
Form type: 4
Filing time: 05 Aug 2025, 16:07:52 UTC
Previous filing: 09 May 2023
SEC: View on sec.gov

Reporting Owners (4)

Name	Relationship	Address	Signature	Signature date	CIK
GV 2021 GP, L.L.C.	10%+ Owner	1600 AMPHITHEATRE PARKWAY, MOUNTAIN VIEW	/s/ Inga Goldbard, General Counsel of GV 2021 GP, L.L.C.	05 Aug 2025	0001861206
GV 2021 GP, L.P.	10%+ Owner	1600 AMPHITHEATRE PARKWAY, MOUNTAIN VIEW	/s/ Inga Goldbard, General Counsel of GV 2021 GP, L.P.	05 Aug 2025	0001861216
GV 2021, L.P.	10%+ Owner	1600 AMPHITHEATRE PARKWAY, MOUNTAIN VIEW	/s/ Inga Goldbard, General Counsel of GV 2021, L.P.	05 Aug 2025	0001861202
Alphabet Inc.	10%+ Owner	1600 AMPHITHEATRE PARKWAY, MOUNTAIN VIEW	/s/ Kathryn W. Hall, Assistant Secretary of Alphabet Inc.	05 Aug 2025	0001652044

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	PRME	Common Stock	Purchase	$4,950,000	+1,500,000	+85%	$3.30	3,262,440	01 Aug 2025	By GV 2021, L.P.	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents shares purchased in connection with an underwritten public offering of the Issuer's Common Stock that closed on August 1, 2025.
F2	The securities reported in this row are directly beneficially owned by GV 2021, L.P. (the "2021 Partnership"). The general partner of the 2021 Partnership is GV 2021 GP, L.P. (the "2021 GP"). The general partner of the 2021 GP is GV 2021 GP, L.L.C. ("GV 2021 LLC"). The sole member of GV 2021 LLC is Alphabet Holdings LLC ("Alphabet Holdings"). The sole member of Alphabet Holdings is XXVI Holdings Inc. ("XXVI"). The controlling stockholder of XXVI is Alphabet Inc. Each of the 2021 GP, GV 2021 LLC, Alphabet Holdings, XXVI, and Alphabet Inc. may be deemed to indirectly beneficially own (as the term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the securities directly beneficially owned by the 2021 Partnership. Each of the aforementioned parties disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

Content

Represents shares purchased in connection with an underwritten public offering of the Issuer's Common Stock that closed on August 1, 2025.

The securities reported in this row are directly beneficially owned by GV 2021, L.P. (the "2021 Partnership"). The general partner of the 2021 Partnership is GV 2021 GP, L.P. (the "2021 GP"). The general partner of the 2021 GP is GV 2021 GP, L.L.C. ("GV 2021 LLC"). The sole member of GV 2021 LLC is Alphabet Holdings LLC ("Alphabet Holdings"). The sole member of Alphabet Holdings is XXVI Holdings Inc. ("XXVI"). The controlling stockholder of XXVI is Alphabet Inc. Each of the 2021 GP, GV 2021 LLC, Alphabet Holdings, XXVI, and Alphabet Inc. may be deemed to indirectly beneficially own (as the term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the securities directly beneficially owned by the 2021 Partnership. Each of the aforementioned parties disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.