Repligen (NASDAQ: RGEN) COO granted options and 7,751 RSUs

Rhea-AI Filing Summary

Repligen Corporation’s Chief Operating Officer James Bylund received new equity awards. He was granted stock options for 8,315 shares of Common Stock at an exercise price of $141.91 per share, expiring on March 5, 2036, vesting in three equal annual installments on March 5, 2027, March 5, 2028, and March 5, 2029. He was also awarded 7,751 restricted stock units, each representing one share of Common Stock, vesting in equal annual installments over three years starting on the first anniversary of the grant date. Following these grants, he holds 25,423 Common Stock shares directly.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Bylund James

Role Chief Operating Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (Right to Buy)	8,315	$0.00	--
Grant/Award	Common Stock	7,751	$0.00	--

Holdings After Transaction: Stock Option (Right to Buy) — 8,315 shares (Direct); Common Stock — 25,423 shares (Direct)

Footnotes (1)

1. Mr. Bylund was awarded 7,751 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 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, and thus, the grant is being reported in Table 1 as allowed per SEC guidance. One third of the stock options will vest and become exercisable annually on March 5, 2027, March 5, 2028, and March 5, 2029.

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^*

Bylund James

(Last) (First) (Middle)

C/O REPLIGEN CORPORATION

41 SEYON ST., BLDG 1, STE 100

(Street)

WALTHAM MASSACHUSETTS 02453

(City) (State) (Zip)

UNITED STATES

(Country)

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 Operating Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/05/2026

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
Common Stock	03/05/2026		A		7,751(1)	A	$0.00	25,423	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)	$141.91	03/05/2026		A		8,315		(2)	03/05/2036	Common Stock	8,315	$0.00	8,315	D

Explanation of Responses:

1. Mr. Bylund was awarded 7,751 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 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, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

2. One third of the stock options will vest and become exercisable annually on March 5, 2027, March 5, 2028, and March 5, 2029.

	/s/ Jennifer Carmichael (Attorney in Fact)	03/23/2026
	** 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 equity awards did Repligen (RGEN) COO James Bylund receive?

James Bylund received stock options for 8,315 shares and 7,751 restricted stock units. The options have a $141.91 exercise price, while the RSUs each represent one share of Repligen Common Stock, subject to multi-year vesting schedules.

How do the new stock options for Repligen (RGEN) COO vest?

The 8,315 stock options granted to the COO vest in three equal annual installments. Vesting dates are March 5, 2027, March 5, 2028, and March 5, 2029, after which vested options become exercisable at $141.91 per share.

What are the vesting terms of the 7,751 RSUs granted by Repligen (RGEN)?

The 7,751 restricted stock units vest in equal annual installments over three years. Vesting begins on the first anniversary of the grant date, and each RSU may only be settled by delivering one share of Repligen Common Stock.

How many Repligen (RGEN) shares does the COO own after these grants?

After the restricted stock unit award, the COO directly holds 25,423 shares of Repligen Common Stock. This figure reflects his updated direct ownership position as reported following the equity grants on the stated grant date.

When do the newly granted Repligen (RGEN) stock options expire?

The stock options granted to the COO expire on March 5, 2036. He must exercise vested options before this expiration date, and each option allows purchase of one Repligen Common share at an exercise price of $141.91.

Are the Repligen (RGEN) RSUs settled in cash or shares?

The restricted stock units may be settled only by delivering shares of Repligen Common Stock. Each RSU corresponds to one share, and the award is therefore reported as a stock-based grant tied directly to future share delivery.