MBX Biosciences (MBX) Proxy filing summary

Board of directors and corporate governance

• Steven L. Hoerter resigned from the Audit Committee and was replaced by Edward T. Mathers effective May 1, 2026.

• Board determined that all directors except P. Kent Hawryluk and Steven L. Hoerter are independent under Nasdaq and SEC rules.

• Audit Committee now consists of Laurie Stelzer (Chair), Tiba Aynechi, and Edward T. Mathers.

• Steven Ryder, M.D., updated as Chief Medical Officer of Yarrow Biosciences as of April 2026.

Audit committee and external auditor matters

• Audit Committee membership updated following resignations and new appointments in 2025 and 2026.

• Edward T. Mathers determined to be independent under Nasdaq Listing Rule 5605(a)(2) and SEC Rule 10A-3(b)(1).

Related party transactions

• Company entered into a Consulting Agreement with Steven L. Hoerter, Executive Chair, effective May 1, 2026.

• Consulting Agreement approved by unanimous written consent of the Board per related party transaction policy.

• Mr. Hoerter received 74,249 nonqualified stock options at $29.78 and 11,938 restricted stock units as part of the agreement.