Prime Medicine (PRME) CEO granted 1,300,000 stock options in new award

Rhea-AI Filing Summary

Reine Allan reported acquisition or exercise transactions in this Form 4 filing.

Prime Medicine, Inc. reported that Chief Executive Officer Reine Allan received a grant of stock options for 1,300,000 shares of company stock. The options were awarded on February 26, 2026 and are held directly. They vest in substantially equal monthly installments, with 1/48 of the underlying shares vesting on each monthly anniversary of February 26, 2026, as long as Allan continues in service on each vesting date.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Reine Allan

Role Chief Executive Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (right to buy)	1,300,000	$0.00	--

Holdings After Transaction: Stock Option (right to buy) — 1,300,000 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Reine Allan

(Last) (First) (Middle)

C/O PRIME MEDICINE, INC.

60 FIRST STREET

(Street)

CAMBRIDGE MA 02141

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Prime Medicine, Inc. [ PRME ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$4.38	02/26/2026		A		1,300,000		(1)	02/26/2036	Common Stock	1,300,000	$0	1,300,000	D

Explanation of Responses:

1. 1/48th of the shares underlying this option vest and become exercisable in substantially equal monthly installments on each monthly anniversary of February 26, 2026, subject to the Reporting Person's continued service on each such vesting date.

Remarks:

	/s/ Ryan Brown, attorney-in-fact	02/27/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did PRME report for CEO Reine Allan?

Prime Medicine reported a grant of stock options to CEO Reine Allan covering 1,300,000 shares. The options were awarded on February 26, 2026 and represent a direct equity-based compensation award.

How many stock options did Prime Medicine (PRME) grant to its CEO?

Prime Medicine granted Reine Allan stock options for 1,300,000 shares. This award gives the CEO the right to buy company stock under the option terms, subject to vesting and continued service conditions.

What is the vesting schedule for Reine Allan’s PRME stock options?

The 1,300,000-share option vests in 48 monthly installments, with 1/48 of the underlying shares vesting each month. Vesting begins on February 26, 2026, and requires Allan’s continued service on each monthly vesting date.

Is Reine Allan’s stock option grant reported as direct ownership in PRME?

Yes. The filing indicates the stock options are held with direct ownership. This means the option award is attributed directly to Reine Allan, rather than through a trust, partnership, or other indirect entity.

Does the PRME Form 4 show any stock sales or disposals by Reine Allan?

No sales or disposals are reported. The Form 4 shows a single transaction coded as an acquisition, reflecting a grant or award of stock options rather than a market purchase or sale of existing shares.