Sutro Biopharma, Inc. (NASDAQ:STRO), a clinical-stage drug discovery, development and manufacturing company focused on the application of precise protein engineering and rational design to create next-generation cancer and autoimmune therapeutics, today 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 (FolRα) 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 FolRα-selected endometrial cancer is planned for later this year.
"We are pleased to advance the clinical development of STRO-002 into dose-expansion studies. Results from our STRO-002 dose escalation in a heavily pre-treated ovarian cancer patient population demonstrated improved outcomes in RECIST response and duration of response," said Dr. Arturo Molina, Chief Medical Officer of Sutro Biopharma. "Sutro plans to expand the study to approximately 35 clinical sites in the U.S. and Europe. We are hopeful that the dose-expansion study will validate the preliminary signs of efficacy we have seen in dose-escalation and provide valuable data on the treatment paradigm and patient population that will benefit from treatment, bringing us one step closer to offering an important new potential treatment option to ovarian cancer patients."
Dr. Lainie Martin, Leader of Gynecology/Oncology Program at Hospital of the University of Pennsylvania and an investigator on the STRO-002-GM1 study, said, "STRO-002 continues to be well-tolerated and we have observed encouraging preliminary activity in patients with advanced platinum-resistant and refractory ovarian cancer. We are excited to be part of the STRO-002-GM1 dose-expansion study and to provide additional clinical data to show the potential of this therapeutic for ovarian patients with limited treatment options."
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 FolRα expression and fresh or archival tumor tissue sample is required for immunohistochemistry (IHC) analysis of FolRα expression.
Additional information on the study can be found at: https://clinicaltrials.gov/ct2/show/NCT03748186
About the Phase 1 Trial of STRO-002 in Ovarian Cancer
STRO-002-GM1, the Phase 1 open-label, multicenter, dose escalation trial with dose expansion of STRO–002, has completed enrollment. Follow-up is ongoing and will continue to evaluate the safety, tolerability, and preliminary anti-tumor activity of STRO-002 in adults with advanced epithelial ovarian cancer, including fallopian and primary peritoneal cancer. The trial is registered with clinicaltrials.gov identifier NCT03748186. Sutro discovered, developed and manufactures STRO-002 using its proprietary XpressCF® cell-free protein synthesis and XpressCF+™ site-specific conjugation technologies.