Martin D. Madaus - 14 May 2026 Form 4 Insider Report for REPLIGEN CORP (RGEN)

Reporting relationship: Director
Issuer ticker: RGEN
Reported as of: 14 May 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 18 May 2026, 16:05:09 UTC
Prior SEC filing: 09 Apr 2026
Source filing: View source filing
Reporting owner signature: /s/ Jennifer Carmichael (Attorney in Fact)

Key filing fact

Martin D. Madaus filed Form 4 for REPLIGEN CORP (RGEN) on 18 May 2026.

Key facts

This page summarizes Martin D. Madaus's Form 4 filing for REPLIGEN CORP (RGEN).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 18 May 2026, 16:05.

Change

Previous filing in this sequence was filed on 09 Apr 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001310268 Primary reporting owner

Madaus Martin D

Relationship: Director
Address: C/O REPLIGEN CORPORATION, 41 SEYON ST., BLDG 1, STE 100, WALTHAM
Signature: /s/ Jennifer Carmichael (Attorney in Fact)
Signature date: 18 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

RGEN transaction

Common Stock

Award

Transaction value
Shares: +995
Change %: +18%
Price: $0.000000^*
Shares after: 6,581
Date: 14 May 2026
Ownership: Direct
Footnotes: F1

RGEN holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 1,800
Date: 14 May 2026
Ownership: By Martin D. Madaus 2011 Revocable Trust

RGEN holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 11
Date: 14 May 2026
Ownership: Spouse Trust

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

RGEN transaction Derivative

Stock Option (Right to Buy)

Award

Transaction value
Shares: +2,239
Change %
Price: $0.000000^*
Shares after: 2,239
Date: 14 May 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 2,239
Exercise price: $103.38
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Mr. Madaus was awarded 995 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 on the earlier of May 14, 2027, one year from the grant date, or the date of the next annual meeting of the Company's shareholders, which has not yet been determined. The Reporting Person has elected to defer settlement of these restricted stock units pursuant to the Repligen Corporation Deferred Compensation Plan for Non-Employee Directors. Once vested, the shares will be issued in accordance with the Reporting Person's deferral election following the separation of the Reporting Person's service as a Director. 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.

Footnote F2

Award vests in full on the earlier of May 14, 2027, one year from grant date, or on the date of the next annual meeting of the Company's shareholders, which has not yet been determined.