Welcome to our dedicated page for SUTRO BIOPHARMA SEC filings (Ticker: STRO), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
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.
Perceptive Advisors LLC, Joseph Edelman, and Perceptive Life Sciences Master Fund, Ltd. report beneficial ownership of Sutro Biopharma common stock on an amended Schedule 13G basis. The Master Fund directly holds 1,304,846 shares of common stock, while Perceptive Advisors and Mr. Edelman may be deemed to beneficially own these shares through their respective roles.
This position represents 7.9% of Sutro Biopharma’s common stock, based on 16,572,171 shares outstanding as of August 7, 2026. The Reporting Persons have shared voting and dispositive power over the 1,304,846 shares and no sole voting or dispositive power.
Sutro Biopharma, Inc. received an updated ownership report from Point72 Asset Management, L.P., Point72 Capital Advisors, Inc., and Steven A. Cohen. The reporting group disclosed beneficial ownership of 237,827 shares of Sutro Biopharma common stock, representing 1.4% of the outstanding class as of the close of business on June 30, 2026.
The shares are held by an investment fund managed by Point72 Asset Management, with Cubist Systematic Strategies, LLC acting as sub-advisor for a portion. The reporting persons have shared voting and dispositive power over all 237,827 shares and no sole voting or dispositive power. They note that this filing should not be construed as an admission of beneficial ownership for Section 13 purposes and confirm that they now hold 5 percent or less of the class.
Sutro Biopharma is a clinical-stage oncology company developing site-specific antibody drug conjugates using its XpressCF and XpressCF+ platforms. For the quarter ended June 30, 2026, the company reported revenue of $9.8 million, down from $63.7 million a year earlier, primarily reflecting the absence of Ipsen-related revenue. Operating expenses fell to $39.7 million from $67.1 million, following 2025 restructuring plans that reduced the workforce by about two-thirds and exited internal GMP manufacturing.
Quarterly net loss widened to $38.5 million from $11.5 million, driven by lower collaboration revenue and continued non-cash interest expense of $9.9 million on a deferred royalty obligation tied to Vaxcyte product royalties. For the first six months of 2026, net loss was $77.0 million, compared with $87.5 million in the prior-year period.
As of June 30, 2026, Sutro had $54.3 million in cash and cash equivalents and $110.0 million in marketable securities, totaling $164.3 million of unrestricted liquidity. Management states this should fund operations for at least 12 months from the reporting date. A February 2026 underwritten offering raised $110.0 million gross ($102.7 million net), but the balance sheet also includes a substantial $239.1 million deferred royalty obligation and a stockholders’ deficit of $103.3 million, underscoring ongoing dependence on external funding and successful advancement of its ADC pipeline, led by STRO-004.
Sutro Biopharma reported second quarter 2026 results and detailed progress across its antibody-drug conjugate pipeline. Revenue for the quarter ended June 30, 2026 was $9.8 million, primarily from its Astellas collaboration, down from $63.7 million a year earlier. Total R&D and G&A expenses declined to $39.5 million from $48.7 million, but net loss widened to $38.5 million versus $11.5 million, or $2.33 loss per share compared with $1.35.
Cash, cash equivalents and marketable securities were $164.3 million as of June 30, 2026, versus $202.6 million as of March 31, 2026, and are expected to support operations into at least the second quarter of 2028. Total assets were $194.5 million and total liabilities $297.8 million, including a $239.1 million deferred royalty obligation, resulting in stockholders’ deficit of $103.3 million.
Clinically, the company highlighted STRO-004 Phase 1 data showing multiple confirmed and ongoing unconfirmed partial responses across several tumor types, mostly low-grade adverse events, a 6% discontinuation rate due to adverse events, and dose-proportional pharmacokinetics with a roughly seven-day half-life. Sutro plans to initiate a Phase 1 trial for STRO-006 in the third quarter of 2026 and submit an IND for dual-payload ADC STRO-227 in 2026, while its first Astellas immunostimulatory ADC program has entered the clinic, triggering a $10 million milestone payment.
BlackRock, Inc. reports beneficial ownership of common stock of Sutro Biopharma, Inc. as of June 30, 2026. BlackRock and certain of its business units collectively hold 1,065,366 shares of Sutro common stock, representing 6.4% of the outstanding class.
BlackRock has sole voting power over 1,052,565 shares and sole dispositive power over all 1,065,366 shares, with no shared voting or dispositive power. Various underlying clients have rights to dividends or sale proceeds, but no single client holds more than five percent of Sutro’s total outstanding common shares.
SUTRO BIOPHARMA, INC. director Jon Marc Wigginton received a grant of stock options covering 10,000 shares of common stock on June 5, 2026. The options have an exercise price of $26.09 per share and represent equity-based compensation rather than an open-market trade.
According to the vesting terms, 8.33% of the award vests monthly starting on July 5, 2026, subject to his continued service. The options will be fully vested and exercisable on the earlier of the company’s 2027 annual stockholders meeting or June 5, 2027. Following this grant, he holds 10,000 options directly.
Sutro Biopharma director Daniel H. Petree received a grant of stock options for 10,000 shares of Common Stock on June 5, 2026. The options have an exercise price of $26.09 per share and expire on June 5, 2036.
The award vests monthly as to 8.33% of the total, starting July 5, 2026, provided he continues to provide services. The options will be fully vested and exercisable on the earlier of the company’s 2027 annual stockholders meeting or June 5, 2027.
Sutro Biopharma director James P. Panek received a grant of stock options covering 10,000 shares of common stock. The options have an exercise price of $26.09 per share and expire on June 5, 2036. They vest 8.33% monthly starting July 5, 2026 and are fully exercisable by the earlier of the 2027 annual stockholders meeting or June 5, 2027, assuming continued service.
Sutro Biopharma director Joseph M. Lobacki received a grant of stock options for 10,000 shares of common stock. The options carry an exercise price of $26.09 per share and expire on June 5, 2036. Vesting is scheduled at 8.33% of the total award each month starting July 5, 2026, and the grant becomes fully vested and exercisable on the earlier of the company’s 2027 annual stockholders meeting or June 5, 2027, subject to his continued service.
Sutro Biopharma director Jagpal Sukhi received a new stock option grant for 10,000 shares of common stock. The option has an exercise price of $26.09 per share and expires on June 5, 2036. This is a compensation-related award rather than an open-market trade.
The option vests over time, with 8.33% of the total award vesting monthly, starting on July 5, 2026. The grant will be fully vested and exercisable on the earlier of the company’s 2027 annual stockholders meeting or June 5, 2027, assuming continued service. After this grant, Sukhi holds options to acquire 10,000 shares directly.