[Form 4] Prime Medicine, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Reine Allan, who is listed as both Chief Executive Officer and a director of Prime Medicine, reported a one-time repricing of certain outstanding stock options effective August 1, 2025. Stockholders approved reducing the per-share exercise price of the affected options to $4.04 from the prior $6.80, aligning the exercise price with the closing market price on the repricing date. The filing shows 850,000 options were repriced and remain governed by their original terms except for the new exercise price; these awards were issued under the 2019 and/or 2022 stock plans and retain their existing vesting schedules and expiration dates (noted as 01/17/2034). The repriced options become exercisable only as they vest and subject to continued service.

Positive

• Stockholder approval was obtained for the repricing, indicating formal governance process compliance
• Exercise price aligned to market ($4.04), which can restore intended economic incentive for the option holder
• Vesting and other original terms remain unchanged, limiting unexpected changes to award structure

Negative

• Large block repriced (850,000 options), which could lead to future dilution if exercised
• Represents additional executive compensation without disclosure here of any offsetting performance conditions or expense details
• Repricing from $6.80 to $4.04 indicates prior strikes were substantially underwater, which some investors view negatively

Insights

Securities Analyst

TL;DR: Executive options were materially repriced to market, benefitting the holder while preserving prior vesting and term conditions.

The Form 4 documents a one-time board- and stockholder-approved adjustment that lowered the exercise price on 850,000 options held by the CEO to $4.04 from $6.80. This action preserves the original vesting schedule and expiration (01/17/2034) and was executed under the company's 2019 and/or 2022 equity plans. From a capital-markets perspective, the repricing reduces the strike gap and increases the likelihood these options will be exercised if the share price rises above $4.04, which may modestly increase future dilution when exercised but does not change current outstanding share count. The filing is procedural and compensatory in nature rather than an operational indicator.

Corporate Governance Expert

TL;DR: Shareholder-approved option repricing raises governance questions about retention, alignment, and disclosure but follows formal plan procedures.

The disclosure confirms stockholder approval for a repricing and notes that all other option terms remain in force. The affected awards totaling 850,000 options were adjusted to the closing market price of $4.04 on the repricing date and remain subject to vesting and continued service. While the filing shows proper procedural steps and explicit plan authority, investors concerned with governance will note the grant size and the executive beneficiary. The document provides clear mechanics but no commentary on shareholder rationale or incremental compensation expense.

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

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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)
08/01/2025

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)	$6.8	08/01/2025		D(1)			850,000	(2)	01/17/2034	Common Stock	850,000	(1)	0	D
Stock Option (right to buy)	$4.04	08/01/2025		A(1)		850,000		(2)	01/17/2034	Common Stock	850,000	(1)	850,000	D

Explanation of Responses:

1. Effective as of August 1, 2025 (the "Repricing Date"), the Issuer's stockholders approved a one-time repricing of certain outstanding stock options (the "Repriced Options") granted under the Issuer's 2019 Stock Option and Grant Plan, as amended (the "2019 Plan") and/or the 2022 Stock Option and Incentive Plan (the "2022 Plan" and, together with the 2019 Plan, the "Plans"), which reduced the per share exercise price of each Repriced Option to $4.04, representing the closing price of the Issuer's common stock on The Nasdaq Global Market on the Repricing Date (the "Option Repricing"). Except as modified by the Option Repricing, all other terms and conditions of the Repriced Options, including, without limitation, any provisions with respect to vesting and term of the Repriced Options, remain in full force and effect.

2. This stock option award was issued pursuant to the 2019 Plan and/or the 2022 Plan, as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

Remarks:

	/s/ Ryan Brown, attorney-in-fact	08/05/2025
	** 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).
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FAQ

What did Prime Medicine (PRME) report on the Form 4 filed for Reine Allan?

The filing reports a one-time repricing of certain stock options held by Reine Allan, reducing the exercise price to $4.04 for 850,000 options.

How many options were repriced and to what exercise price?

A total of 850,000 option awards were repriced to an exercise price of $4.04 (previously $6.80).

When did the option repricing become effective for PRME?

The repricing is effective as of August 1, 2025, the date referenced as the "Repricing Date" in the filing.

Do the repriced options have modified vesting or expiration terms?

No. The filing states that, except for the exercise price, all other terms including vesting schedules and term remain in full force; expiration is shown as 01/17/2034.

Under which plans were the repriced options issued?

The repriced awards were issued under the company’s 2019 Stock Option and Grant Plan and/or the 2022 Stock Option and Incentive Plan.