Inhibrx Reports Strong Phase 2 Data for OX40 Agonist in HNSCC

The randomized clinical trial, which enrolled patients with treatment-naïve metastatic or recurrent disease, reported a confirmed objective response rate of 48.3% for the combination therapy, nearly doubling the 26.5% rate observed in patients receiving pembrolizumab alone. Median progression-free survival reached 9.6 months for the combination arm, compared to 4.9 months for the control group.

Efficacy signals were particularly robust among patients with HPV-positive disease. In this subgroup, the combination achieved an 80% objective response rate, with 30% of patients reaching a complete response, while the control arm saw no such responses. The durability of the treatment was marked by a 90% progression-free survival rate at six months for the combination, significantly outpacing the 33% seen in the monotherapy cohort.

Inhibrx plans to expand the study by 50 additional HPV-positive patients to support a potential accelerated regulatory pathway. CEO Mark Lappe stated that the durability of these responses validates the company’s focus on OX40-mediated T-cell costimulation. Beyond head and neck cancer, the company intends to test the drug’s potential in other highly immunogenic solid tumors and in conjunction with therapeutic cancer vaccines.