Gregory K. Chow - 02 Mar 2026 Form 4 Insider Report for SUTRO BIOPHARMA, INC. (STRO)

Role
CFO
Signature
/s/ David Pauling as attorney-in-fact
Issuer symbol
STRO
Transactions as of
02 Mar 2026
Net transactions value
$0
Form type
4
Filing time
03 Mar 2026, 18:51:52 UTC
Previous filing
29 Dec 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Chow Gregory K. CFO C/O SUTRO BIOPHARMA, INC., 111 OYSTER POINT BOULEVARD, SOUTH SAN FRANCISCO /s/ David Pauling as attorney-in-fact 03 Mar 2026 0001761333

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 STRO Stock Option (right to buy) Award $0 +40,000 $0.000000 40,000 02 Mar 2026 Common Stock 40,000 $20.55 Direct F1
transaction STRO Restricted Stock Units (RSUs) Award $0 +5,000 $0.000000 5,000 02 Mar 2026 Common Stock 5,000 Direct F2, F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 1/48 of the total option award shall vest monthly, subject to the reporting person's continued service through each vesting date, with the first tranche vesting on April 1, 2026.
F2 Each RSU represents a contingent right to receive one (1) share of the Issuer's Common Stock upon settlement.
F3 The RSUs shall vest as to 1/4 of the total award annually, with the first tranche vesting on March 1, 2027, subject to continued service through each vesting date.

Remarks:

Effective as of 12:01 a.m. Eastern time on December 3, 2025, pursuant to a Certificate of Amendment to the Issuer's Restated Certificate of Incorporation previously approved by the Issuer's stockholders, and filed with the Delaware Secretary of State on December 2, 2025, the Issuer's Common Stock, par value $0.001 per share, underwent a 1-for-10 reverse stock split (the "Reverse Stock Split"). All amounts, including all dollar values, set forth herein have been adjusted to reflect the Reverse Stock Split.