BioAtla presents Phase 2 Oz-V clinical trial data at ASCO 2025

BioAtla (BCAB) announced data in a poster titled, “Phase 2 Trial of Ozuriftamab Vedotin, a Conditionally Binding CAB-ROR2-ADC, in Patients with Heavily Pretreated Squamous Cell Carcinoma of the Head and Neck.” The poster will be presented today at the 2025 American Society of Clinical Oncology Annual Meeting at the McCormick Place Convention Center in Chicago, Illinois. In the Phase 2 clinical trial, patients with heavily pretreated squamous cell carcinoma of the head and neck received 1.8 mg/kg of Oz-V given in two schedules: once every two weeks or days 1 and 8 of a 21-day cycle. Tumor assessments were conducted by CT or MRI every 6 weeks from cycle 1 day 1 until week 12, then every 8 weeks up to one year. Response-evaluable patients included those with at least one post-treatment scan. HPV associated expression of E6 and/or E7 oncoproteins drives cancer progression by upregulating ROR2 expression, which is expressed at high rates in OPSCC. Thus, there is a compelling rationale to evaluate Oz-V in HPV associated OPSCC patients. Data highlights from the abstract and poster include: 40 patients received Oz-V either Q2W or 2Q3W for a median of 85 days. Patients received a median of 3 prior lines of therapy; all pts had experienced prior failure of anti-PD-1 therapy and 85% of pts experienced prior failure of platinum therapy. For the efficacy analysis, 22 pts had HPV+ OPSCC; safety data presented were based on the full dataset. In HPV+ OPSCC pts, Oz-V demonstrated compelling antitumor activity in patients receiving 1.8 mg/kg Q2W. ORR 45%, 27% confirmed, DCR 100%, continuing follow-up. Median duration of response 9.9 months, median progression-free survival 4.7 months, and median overall survival 11.6 months and ongoing. Other studies using standard of care agents have reported ORR of 3.4% and OS of 4.4 months among HPV+ OPSCC pts. Based on the head and neck cancer dataset, most adverse events were low grade; fatigue and anemia were most frequent. At the 1.8 mg/kg Q2W regimen, to date, only 3 patients experienced related grade greater than or equal to3 AEs, and there were no related serious AEs; also, only 1 patient discontinued due to a related AE. Oz-V has the potential to address the marked unmet need among the recurrent/metastatic HPV+ OPSCC population. Oz-V has Fast Track Designation to facilitate additional discussions with the FDA for final agreement on a proposed Phase 3 study.