Inhibrx announces preliminary ozekibart data, initiates new expansion cohort

Inhibrx (INBX) announced preliminary efficacy and safety data from the Phase 1 trial of ozekibart in combination with Folfiri for the treatment of advanced or metastatic, unresectable colorectal adenocarcinoma. These results were presented at the American Society of Clinical Oncology Gastrointestinal Annual Cancers Symposium. Efficacy was assessed in 10 of the 13 patients who received at least one dose of ozekibart, based on RECIST v1.1 criteria. Results demonstrated one complete response, three partial responses, and six cases of stable disease. Durable disease control lasting 180 days was observed in 46.2% of patients, with a median progression-free survival of 7.85 months. All patients had received at least one prior line of systemic therapy. Notably, the patient achieving a CR had undergone three prior lines of therapy, and two PRs occurred in patients who had failed prior FOLFIRI-based treatments. Ozekibart-related treatment-emergent adverse events were reported in 84.6% of patients, with most being grade 1 or 2 in severity. Grade 3 TEAEs were observed in 30.8% of patients. The most common ozekibart-related TEAEs included nausea, increased alanine aminotransferase, diarrhea, and fatigue, with the majority being low-grade. Encouraged by these preliminary results, Inhibrx has initiated a new expansion cohort to validate these findings in a more uniform patient population. The cohort is expected to enroll up to 50 patients, each with two to three prior lines of systemic therapy, and data are anticipated in Q3 2025.