Sutro Biopharma, Inc. announced the dosing of the first patient in the dose-expansion cohort of the Phase 1 STRO-002 study. STRO-002 is an internally developed, folate receptor alpha (FolRa) targeting antibody-drug conjugate (ADC) for the potential treatment of ovarian cancer. The dose-expansion cohort will assess the efficacy, safety and tolerability of STRO-002 at 4.3 and 5.2 mg/kg, given every 3 weeks in patients with ovarian cancer. The dose-expansion cohort for FolRa-selected endometrial cancer is planned for later this year. The dose-expansion study includes two patient cohorts, advanced epithelial ovarian cancer and endometrial cancer. The ovarian cancer cohort currently enrolling includes patients with platinum resistant disease and have received 1-3 prior regimens or platinum sensitive patients that have received 2-3 prior treatment regimens. Patients in the dose-expansion cohort of the STRO-002-GM1 Phase 1 study will be randomized 1:1 and treated with either 4.3 or 5.2 mg/kg STRO-002 intravenously once every three-weeks. Patients will not be pre-selected for FolRa expression and fresh or archival tumor tissue sample is required for immunohistochemistry (IHC) analysis of FolRa expression.