Changes in Beneficial Ownership · 4
Sutro Biopharma, Inc.
STRONASDAQEQUITYCurrent
Changes in Beneficial Ownership
Structured filing — 4
form4-06092026_080631.xml
Filing details
- Report period
- 2026-06-05
- Issuer
- SUTRO BIOPHARMA, INC.
- Issuer CIK
- 0001382101
- Trading symbol
- STRO
Reporting owner 1
- Name
- Hunter Heidi
- Reporting owner CIK
- 0001891841
- Relationship
- Director
- Address
- C/O SUTRO BIOPHARMA, INC., 111 OYSTER POINT BLVD., SOUTH SAN FRANCISCO, CA, 94080
Derivative transactions
| Security | Conversion / exercise price (USD) | Transaction date | Code | Amount | A / D | Price (USD) | Exercisable | Expires | Underlying security | Underlying shares | Owned after | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Stock Option (right to buy) | 26.09 | 2026-06-05 | A · Form 4 | 10,000 | A | 0 | [F1] | 2036-06-05 | Common Stock | 10,000 | 10,000 | D |
Table key
- A · Form 4
- Acquisition by grant, award or otherwise under Rule 16b-3(d)
- A
- Acquired
- D
- Direct
Footnotes
- F1
- The option shall vest, subject to the reporting person's provision of service to the issuer on each vesting date, as to 8.33% of the total award monthly, with the first tranche vesting on July 5, 2026, and the award shall be fully vested and exercisable on the earlier of (i) the date of the issuer's 2027 annual stockholders meeting or (ii) June 5, 2027.↩ 1
Signature 1
- Signed
- /s/ David Pauling as attorney-in-fact
- Date
- 2026-06-09
Company context
Sutro Biopharma, Inc. is a clinical-stage biotechnology company advancing a next-generation antibody-drug conjugate (ADC) platform designed to deliver single- and dual-payload ADCs that enable meaningful breakthroughs for patients with cancer. By fully optimizing the antibody, linker, and payload, Sutro’s cell-free platform produces ADCs that are engineered to improve drug exposure, reduce side effects, and expand the range of treatable tumor types. With