Repligen (RGEN) CPO discloses 6,252 shares and stock options holdings

Rhea-AI Filing Summary

Repligen Corporation’s Chief Product Officer, Douglass Brian Robb, reported his beneficial ownership as of December 31, 2025. He directly holds 6,252 shares of Repligen common stock, which include restricted stock units granted on May 7, 2024 (4,000 units vesting in equal annual installments over five years) and on March 1, 2025 (2,252 units vesting in equal annual installments over four years).

He also holds two stock option awards, each exercisable for Repligen common stock at an exercise price of $167.72 per share and expiring on May 7, 2034: one covering 2,980 shares, with 596 shares already vested and the remainder vesting annually from May 7, 2026 through May 7, 2029, and another covering 7,020 shares, with 1,404 shares vested and the rest vesting on the same schedule. All reported holdings are listed as directly owned.

Insider Trade Summary

3 transactions reported

Mixed 3 txns

Insider Douglass Brian Robb

Role CHIEF PRODUCT OFFICER

Type	Security	Shares	Price	Value
holding	Stock Option (Right to Buy)	--	--	--
holding	Stock Option (Right to Buy)	--	--	--
holding	Common Stock	--	--	--

Holdings After Transaction: Stock Option (Right to Buy) — 2,980 shares (Direct); Common Stock — 6,252 shares (Direct)

Footnotes (1)

1. Represent restricted stock units that were awarded to represent a contingent right to receive one share of Repligen Corporation's Common Stock. The restricted stock units may be settled only by delivering shares of Repligen Corporation's Common Stock. 4,000 of the restricted stock units were granted on May 7, 2024 and vest in equal installments over a five-year period with each such vesting date occurring on the anniversary of the grant date. 2,252 of the restricted stock units were granted on March 1, 2025 and vest in equal installments over a four-year period with each such vesting date occurring on the anniversary of the grant date. The stock option was granted on May 7, 2024 and vest in equal installments over a five-year period with such vesting date occurring on the anniversary of the grant date. 596 shares have vested and the remaining shares will vest in equal installments on May 7, 2026, May 7, 2027, May 7, 2028 and May 7, 2029. The stock option was granted on May 7, 2024 and vest in equal installments over a five-year period with such vesting date occurring on the anniversary of the grant date. 1,404 shares have vested and the remaining shares will vest in equal installments on May 7, 2026, May 7, 2027, May 7, 2028 and May 7, 2029.

Understanding Insider Trading Forms →

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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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OMB Number:			3235-0104
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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. Date of Event Requiring Statement (Month/Day/Year)
12/31/2025

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

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

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

5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	6,252(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	(2)	05/07/2034	Common Stock	2,980	$167.72	D
Stock Option (Right to Buy)	(3)	05/07/2034	Common Stock	7,020	$167.72	D

Explanation of Responses:

1. Represent restricted stock units that were awarded to represent a contingent right to receive one share of Repligen Corporation's Common Stock. The restricted stock units may be settled only by delivering shares of Repligen Corporation's Common Stock. 4,000 of the restricted stock units were granted on May 7, 2024 and vest in equal installments over a five-year period with each such vesting date occurring on the anniversary of the grant date. 2,252 of the restricted stock units were granted on March 1, 2025 and vest in equal installments over a four-year period with each such vesting date occurring on the anniversary of the grant date.

2. The stock option was granted on May 7, 2024 and vest in equal installments over a five-year period with such vesting date occurring on the anniversary of the grant date. 596 shares have vested and the remaining shares will vest in equal installments on May 7, 2026, May 7, 2027, May 7, 2028 and May 7, 2029.

3. The stock option was granted on May 7, 2024 and vest in equal installments over a five-year period with such vesting date occurring on the anniversary of the grant date. 1,404 shares have vested and the remaining shares will vest in equal installments on May 7, 2026, May 7, 2027, May 7, 2028 and May 7, 2029.

Remarks:

Exhibit 24.1: Power of Attorney

	/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 5 (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 filed this ownership report for Repligen (RGEN)?

The report was filed by Douglass Brian Robb, who serves as Chief Product Officer of Repligen Corporation.

How many Repligen (RGEN) common shares does Douglass Brian Robb directly own?

He directly beneficially owns 6,252 shares of Repligen common stock as of December 31, 2025, including restricted stock units that settle in shares.

What restricted stock units does the Repligen CPO hold and how do they vest?

He holds restricted stock units that settle in Repligen common stock: 4,000 units granted on May 7, 2024 vesting in equal annual installments over five years, and 2,252 units granted on March 1, 2025 vesting in equal annual installments over four years.

What stock options does Douglass Brian Robb have in Repligen (RGEN)?

He holds two stock options granted on May 7, 2024, each with an exercise price of $167.72 per share and expiring on May 7, 2034: one for 2,980 shares and another for 7,020 shares of Repligen common stock.

How much of the Repligen CPO’s stock options are already vested?

For the 2,980-share option, 596 shares have vested. For the 7,020-share option, 1,404 shares have vested. The remaining shares in each grant vest in equal installments on May 7, 2026, May 7, 2027, May 7, 2028, and May 7, 2029.

Are Douglass Brian Robb’s Repligen (RGEN) holdings reported as direct or indirect?

All reported holdings in common stock and stock options are listed as directly owned (D) with no separate nature of indirect beneficial ownership noted.