Inhibrx’s OX40 agonist plus Keytruda shows 48% response rate, beating Keytruda alone in head and neck cancer Phase 2

Inhibrx reported results from its Phase 2 HexAgon trial evaluating INBRX-106, an OX40 receptor agonist, combined with Merck’s Keytruda in patients with treatment‑naïve, PD‑L1‑positive metastatic or unresectable recurrent head and neck squamous cell carcinoma.

The interim analysis of 68 patients showed a confirmed objective response rate of 48.3% in the combination arm (29 patients) versus 26.5% in the Keytruda‑only arm. Four patients receiving the combo achieved complete responses, while none did in the monotherapy group.

The data suggest the OX40 agonist may enhance the immune activation provided by pembrolizumab, and the company’s CEO highlighted a potential near‑term market opportunity of roughly $4 billion, citing the broader $50 billion head‑and‑neck cancer market.