Inhibrx sees positive Ox40 signs

Inhibrx has been rewarded for persevering in an unloved target, Ox40 agonism, with positive phase 2 results from its phase 2/3 Hexagon trial of its contender, INBRX-106. The study compares a Keytruda combo versus Keytruda alone, in first-line head and neck cancer patients with ≥20% PD-L1 expression. On Monday Inhibrx said the doublet produced an ORR of 44%, versus 21% with Keytruda; the latter result was in line with the 23% ORR seen in Keynote-048. As for safety, Inhibrx merely said adverse events were predominantly low-grade, and there were no treatment-related deaths. The company plans to start the phase 3 portion of Hexagon next quarter; this will primarily measure PFS and OS. Keynote-048 has provided the bar to hit here, of 3.4 and 14.9 months respectively. Inhibrx will also report PFS data from the phase 2 part of Hexagon in the fourth quarter. Elsewhere, the group plans trials in first-line and perioperative NSCLC. Several players have dropped out of Ox40 agonism, including Pfizer, Bristol Myers Squibb and AbbVie, and BeOne also appears to have canned gimistotug since ApexOnco last looked at this mechanism. Still, head and neck cancer is looking increasingly competitive, and Inhibrx stock closed down 5%.

Within & cross-trial comparison in first-line HNSCC (PD-L1 ≥20%)

Note: Hexagon data cutoff 7 May 2026. Source: OncologyPipeline & company release.