ROR2-ADC Ozuriftamab Vedotin Posts 36% ORR in PD-1-Refractory Head-and-Neck Cancer

Ozuriftamab vedotin is a conditionally binding antibody–drug conjugate that releases MMAE only in the low-pH tumor microenvironment to target ROR2. In this open-label Phase 2 trial (NCT03504488), 31 patients with heavily pretreated recurrent / metastatic SCCHN that failed to respond to anti-PD-1 measures (median 3 prior lines) received 1.8 mg/kg IV either Q2W (n = 12) or on Days 1 & 8 of a 21-day cycle (n = 19). Among 28 evaluable patients, investigator-assessed ORR was 36% (1 CR, 9 PRs) with an 86% disease-control rate; median duration of confirmed responses is not yet reached (>3.6 mo). Most adverse events were Grade 1-2 (fatigue 59%, anemia 34%, nausea 34%); treatment-related Grade 3 events occurred in 19% and Grade 4 in 2 patients (hyponatremia, neuropathy); no Grade 5 toxicity was seen.