Laurie Stelzer - 20 Jan 2026 Form 4 Insider Report for MBX Biosciences, Inc. (MBX)

Role
Director
Signature
/s/ Richard Bartram, attorney-in-fact
Issuer symbol
MBX
Transactions as of
20 Jan 2026
Net transactions value
$0
Form type
4
Filing time
22 Jan 2026, 08:08:56 UTC
Previous filing
16 Jun 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Stelzer Laurie Director C/O MBX BIOSCIENCES, INC., 11711 N. MERIDIAN STREET, STE 300, CARMEL /s/ Richard Bartram, attorney-in-fact 22 Jan 2026 0001644348

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction MBX Stock option (right to buy) Award $0 +32,000 $0.000000 32,000 20 Jan 2026 Common Stock 32,000 $43.14 Direct F1
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 One-third of the shares underlying this option will vest and become exercisable on January 20, 2027, the anniversary of the date of grant, with the remainder vesting monthly over the subsequent two year period, subject to the Reporting Person's continued service on each such vesting date.