Sutro Biopharma, Inc. announced new nonclinical data for its folate receptor alpha (FolRa) targeting antibody-drug conjugate (ADC) STRO-002, in an e-poster session, at the American Association for Cancer Research (AACR) Annual Meeting 2022, being held virtually and in New Orleans from April 8-13, 2022. STRO-002 is an ADC designed to target FolRa, which is currently in Phase 1 clinical trials for the treatment of ovarian and endometrial cancers. In the e-poster session presented at AACR, studies in vitro demonstrate STRO-002's ability to induce hallmarks of immunogenic cell death.

Studies in vivo show that pre-administration of STRO-002 to FolRa-expressing tumor cells confers anti-tumor immunity as demonstrated by both rejection of the primary tumor and significant protection after a tumor re-challenge. Further, in vivo induction of immunogenic cell death extended to a complementary anti-tumor mechanism in combination with a checkpoint inhibitor (avelumab) in re-challenged animals. Additionally, when STRO-002 was administered in combination with an anti-VEGF antibody (bevacizumab), the tumor growth was significantly inhibited.

Nonclinical studies using endometrial and non-small cell lung cancer (NSCLC) patient derived xenograft models with diverse levels of FolRa expression demonstrated robust STRO-002 activity, with the degree of efficacy correlating with FolRa levels. Similar activity was also seen in cells with moderate to low levels of FolRa expression. In the NSCLC model, a STRO-002 dose of 10 mg/ml resulted in significant and long-term responses.