REPLIGEN CORP 8-K

What Happened
Repligen Corporation filed a Form 8-K on January 6, 2026 announcing that its Board of Directors has elected Dr. Martin D. Madaus as Chair of the Board, effective March 13, 2026. Dr. Madaus will succeed Tony J. Hunt, who will retire from the Board on that Effective Date; Mr. Hunt is currently serving as Executive Chair. The company attached a press release (Exhibit 99.1) to the filing.

Key Details

• Filed: January 6, 2026 (Form 8-K).
• Effective Date: March 13, 2026 — Dr. Martin D. Madaus becomes Board Chair; Tony J. Hunt retires from the Board on that date.
• Independence: The Board previously determined Dr. Madaus is an independent director under SEC and Nasdaq rules.
• Disclosure: Company issued a press release attached as Exhibit 99.1 to the 8-K.

Why It Matters
A change in board leadership is a governance event investors watch because it can affect board oversight and strategic continuity. This filing confirms a planned, disclosed transition (not an unanticipated departure) and that the new chair is an independent director, which bears on corporate governance structure. The 8-K does not report changes to executive management, compensation, or financial results.