SUTRO BIOPHARMA, INC. 4

CFO Gregory K. Chow had 2,500 RSUs convert into 2,500 shares of Sutro Biopharma, Inc. (STRO) common stock on June 2, 2026, increasing his direct holdings to 7,500 shares.

On June 2, 2026, Sutro Biopharma, Inc. CFO Gregory K. Chow reported the vesting and settlement of 2,500 Restricted Stock Units into an equal number of shares of common stock, with the transaction coded as an exempt, non-open-market acquisition. Following this RSU conversion, Chow directly owned 7,500 shares of Sutro Biopharma common stock. The footnotes clarify that tax withholding obligations were satisfied in cash rather than through share withholding, and that the reported ownership total also includes 250 shares previously acquired under the issuer’s employee stock purchase plan. The RSU award vests in four annual installments of 25%, contingent on continued service, with the first tranche vesting on June 2, 2026.

Filing Facts

CIK

1382101

Ticker

STRO

Form

4

Source Type

sec

Accession

0001761333-26-000005

Alert Tier

5