Sutro Biopharma filings document the regulatory record of a clinical-stage oncology biotechnology company developing site-specific antibody-drug conjugates. Its SEC disclosures cover operating and financial results, research and development priorities, clinical and regulatory updates for ADC programs, collaboration-related matters, risk factors, and capital-structure activity involving its common stock.
The company’s filings also include definitive proxy materials on shareholder voting, board matters, executive compensation and equity awards. Form 8-K reports document material events such as agreement terminations, restructuring costs, Nasdaq listing-rule notices and compliance updates, and other corporate actions affecting governance, reporting status and financing flexibility.
Affinity Asset Advisors and Michael Cho report ownership of 1,069,519 shares of Sutro Biopharma common stock, representing approximately 6.5% of the outstanding common stock as of March 31, 2026.
The filing states the percentage is calculated using 16,567,762 shares outstanding as of March 31, 2026, per the issuer's Definitive Proxy Statement filed April 22, 2026. The Reporting Persons hold sole voting and sole dispositive power over the reported shares.
Sutro Biopharma filed a Schedule 13G showing 946,829 shares of Common Stock beneficially owned by Point72-related reporting persons. The filing states this equals 5.7% of the class as of the close of business on April 30, 2026. The holdings are reported on behalf of Point72 Associates, with voting and dispositive power shared by Point72 Asset Management, Point72 Capital Advisors Inc., and Steven A. Cohen under a joint filing agreement.
Sutro Biopharma, Inc. is holding a virtual 2026 Annual Meeting of Shareholders on June 5, 2026. Stockholders will vote to elect three Class II directors (Jane Chung, Connie Matsui and James Panek) for three-year terms, ratify Ernst & Young LLP as auditor for 2026, and approve on an advisory basis the compensation of named executive officers.
Stockholders of record at the close of business on April 7, 2026, when 16,567,887 common shares were outstanding, may vote. The board is majority independent, with separate Chair and CEO roles and active Audit, Compensation, Nominating and Governance, and Science and Technology Committees. The proxy describes a pay-for-performance executive compensation program emphasizing equity awards and annual incentives, and notes prior Say-on-Pay support of 77.7% in 2025.
Sutro Biopharma files an amendment to a Schedule 13G/A reporting joint beneficial ownership of 210,378 shares of common stock, representing 1.3% of the class. The filing lists Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander as joint filers and includes a Joint Filing Agreement dated April 20, 2026.
The cover data shows the class CUSIP as 869367201 and an apparent as-of date of 03/31/2026 on the reporting header. Signatures are provided by Gil Raviv and Israel A. Englander.
Sutro Biopharma, Inc. beneficial ownership filing: Perceptive Advisors, Joseph Edelman and Perceptive Life Sciences Master Fund, Ltd. report shared beneficial ownership of 898,025 shares of Common Stock, equal to 5.4% of the class. Shares outstanding were 16,567,238 as of March 16, 2026.
The Master Fund directly holds 898,025 shares; Perceptive Advisors is the fund's investment manager and Mr. Edelman is its managing member and may be deemed to beneficially own the shares. The filing is signed by Joseph Edelman.
Sutro Biopharma is registering up to $100.0 million of common stock for sale under a Sales Agreement with TD Securities (USA) LLC (TD Cowen) pursuant to an at-the-market program. Sales may occur from time to time in negotiated transactions, block trades or other methods permitted under Rule 415.
The shares trade on Nasdaq under the symbol STRO (last reported sale $24.91 on March 31, 2026). The prospectus supplement states there were 8,584,309 shares outstanding as of December 31, 2025 and discloses dilution and net tangible book value metrics tied to an illustrative $100.0 million placement.
Sutro Biopharma, Inc. filed a shelf registration and preliminary prospectus permitting up to $300.0 million of securities and a prospectus supplement enabling an at-the-market program to sell up to $100.0 million of common stock through TD Securities (USA) LLC (TD Cowen) as agent or principal. The sales agreement contemplates negotiated transactions and at-the-market distributions, with compensation to TD Cowen of up to 3.0% of gross proceeds. The company reported 8,584,309 shares outstanding as of December 31, 2025, and the last reported sale price was $21.12 per share on March 19, 2026.
Sutro Biopharma is a clinical-stage oncology company focused on next‑generation antibody-drug conjugates (ADCs) built on its proprietary cell-free protein synthesis platforms XpressCF® and XpressCF+®. Its lead wholly owned program, STRO‑004, targets tissue factor in multiple solid tumors and entered a Phase 1 trial in late 2025, with initial data expected in mid‑2026.
Preclinical assets include STRO‑006 (ITGβ6‑targeted ADC) and STRO‑227 (dual‑payload PTK7‑targeted ADC), with planned IND filings between 2026 and early 2027. The company highlights its ability to precisely place non‑natural amino acids to create homogeneous, high‑DAR ADCs and dual‑payload constructs, including immunostimulatory ADCs (iADCs) and dpADCs.
Sutro reports aggregate collaboration payments of about $1.016 billion through December 31, 2025, including a $90.0 million upfront from Astellas and a $140.0 million royalty monetization with Blackstone tied to Vaxcyte vaccines. Market value of non‑affiliate equity was approximately $60.0 million as of June 30, 2025, with 16,567,238 shares outstanding as of March 16, 2026.