Equity awards grant Repligen (RGEN) product chief 2,288 RSUs, options

Rhea-AI Filing Summary

Repligen Corporation reported new equity awards to its Chief Product Officer, Douglass Brian Robb. On 12/31/2025, he received 2,288 restricted stock units, each representing one share of Repligen common stock. These restricted stock units vest in substantially equal annual installments over three years, beginning on the first anniversary of the grant date, and are settled only in shares of common stock.

On the same date, he was also granted a stock option for 2,143 shares of common stock at an exercise price of $163.86 per share, expiring on 12/31/2035. Following the restricted stock award, he directly beneficially owned 8,540 shares of common stock, and 2,143 stock options were beneficially owned directly after the option grant.

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^*

Douglass Brian Robb

(Last) (First) (Middle)

C/O REPLIGEN CORPORATION

41 SEYON ST., BLDG 1, STE 100

(Street)

WALTHAM MA 02453

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
REPLIGEN CORP [ RGEN ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF PRODUCT OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
12/31/2025

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
Common Stock	12/31/2025		A		2,288(1)	A	$0.00	8,540	D

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)	$163.86	12/31/2025		A		2,143		(2)	12/31/2035	Common Stock	2,143	$0.00	2,143	D

Explanation of Responses:

1. Mr. Douglass was awarded 2,288 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of Repligen Corporation's Common Stock. The restricted stock units vest in substantially equal annual instalments over a three-year period beginning on the first anniversary of the grant date. The restricted stock units may be settled only by delivering shares of Repligen Corporation's Common Stock.

2. The shares will vest in substantially equal installments over a three-year period with each such vesting date occurring on the anniversary of the grant date.

	/s/ Meghan Stapleton (Attorney in Fact)	01/12/2026
	** 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).
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FAQ

What insider transaction did Repligen (RGEN) disclose for Douglass Brian Robb?

Repligen disclosed that Chief Product Officer Douglass Brian Robb received 2,288 restricted stock units and a stock option for 2,143 shares on 12/31/2025.

How do the 2,288 restricted stock units for RGEN’s chief product officer vest?

The 2,288 restricted stock units vest in substantially equal annual installments over a three-year period, starting on the first anniversary of the grant date.

What are the terms of the stock options granted to Repligen’s chief product officer?

The stock option covers 2,143 shares of Repligen common stock with an exercise price of $163.86 per share and an expiration date of 12/31/2035.

How many Repligen common shares does Douglass Brian Robb own after this Form 4?

After the reported transaction, Douglass Brian Robb directly beneficially owned 8,540 shares of Repligen common stock.

How many stock options does Douglass Brian Robb hold after the grant reported by Repligen?

Following the grant, Douglass Brian Robb beneficially owned 2,143 stock options directly, representing rights to acquire that number of Repligen shares.

How will the Repligen restricted stock units reported on this Form 4 be settled?

The restricted stock units may be settled only by delivering shares of Repligen Corporation's common stock upon vesting.