Prime Medicine (PRME) awards CFO 800,000 stock options at $3.67

Rhea-AI Filing Summary

Prime Medicine, Inc. reported that Chief Financial Officer Svetlana Ni Makhni received a grant of stock options covering 800,000 shares of common stock. The options have an exercise price of $3.67 per share and expire on April 16, 2036.

According to the terms, 25% of the shares underlying this option will vest on April 16, 2027, with the remaining shares vesting in equal monthly installments over the following 36 months, subject to her continued service. After this grant, she holds options on 800,000 shares directly.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Makhni Svetlana Ni

Role Chief Financial Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (right to buy)	800,000	$0.00	--

Holdings After Transaction: Stock Option (right to buy) — 800,000 shares (Direct)

Footnotes (1)

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Key Figures

Option grant size: 800,000 options Exercise price: $3.67 per share Expiration date: April 16, 2036 +4 more

7 metrics

Option grant size 800,000 options Stock Option (right to buy) granted to CFO

Exercise price $3.67 per share Conversion or exercise price of the option

Expiration date April 16, 2036 Option term end date

Underlying shares 800,000 shares Common Stock underlying the option

Initial vesting cliff 25% on April 16, 2027 Portion of options that vest on first vesting date

Remaining vesting period 36 months Monthly vesting period after initial 25% cliff

Post-grant holdings 800,000 options Total options held following the transaction

Key Terms

Stock Option (right to buy), exercise price, vesting, expiration date, +1 more

5 terms

Stock Option (right to buy) financial

"security_title: Stock Option (right to buy)"

exercise price financial

"conversion_or_exercise_price: 3.6700"

The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.

vesting financial

"shares underlying this option shall vest on April 16, 2027"

Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.

expiration date financial

"expiration_date: 2036-04-16T00:00:00.000Z"

The expiration date is the deadline after which a financial contract, such as an option or a futures agreement, is no longer valid or can be exercised. It matters to investors because it determines the timeframe during which they can take action or benefit from the contract, similar to how a coupon or a food item has a limited period of usefulness. Once the expiration date passes, the contract loses its value or ability to be used.

Common Stock financial

"underlying_security_title: Common Stock"

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

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^*

Makhni Svetlana Ni

(Last) (First) (Middle)

C/O PRIME MEDICINE, INC.

60 FIRST STREET

(Street)

CAMBRIDGE MASSACHUSETTS 02141

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/16/2026

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

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

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

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)	$3.67	04/16/2026		A		800,000		(1)	04/16/2036	Common Stock	800,000	$0	800,000	D

Explanation of Responses:

1. 25% of the shares underlying this option shall vest on April 16, 2027 and the balance will vest monthly in equal instalments over the following 36 months, subject to the Reporting Person's continued service on each such vesting date.

Remarks:

	/s/ Ryan Brown, attorney-in-fact	04/17/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What did Prime Medicine (PRME) disclose about its CFO in this Form 4?

Prime Medicine reported that CFO Svetlana Ni Makhni received a stock option grant for 800,000 shares of common stock at a $3.67 exercise price. These options are a compensation award, not an open-market stock purchase or sale, and vest over several years.

How many Prime Medicine (PRME) shares are covered by the new option grant?

The new stock option grant covers 800,000 shares of Prime Medicine common stock. This entire amount is subject to a multi-year vesting schedule, meaning the CFO gains the right to exercise portions of the option gradually rather than all at once.

What is the exercise price and term of the CFO’s Prime Medicine (PRME) options?

The granted stock options have an exercise price of $3.67 per share and expire on April 16, 2036. This gives the CFO a long window to potentially purchase shares at that set price once the options have vested over time.

How do the Prime Medicine (PRME) options granted to the CFO vest over time?

Twenty-five percent of the shares underlying this option vest on April 16, 2027. The remaining 75% then vest in equal monthly installments over the following 36 months, provided the CFO continues in service on each vesting date.

Is the Prime Medicine (PRME) CFO’s option grant an open-market transaction?

No. The filing describes an “A” code grant, meaning it is a compensation-related award, not an open-market buy or sell. The CFO did not purchase shares in the market; instead, she received options giving the right to buy future shares at $3.67.