Inhibrx Biosciences reported positive results from a Phase 2 study of a potential treatment for metastatic or unresectable recurrent head and neck squamous cell carcinoma.

The clinical-stage biopharmaceutical company said Tuesday its INBRX-106 drug in combination with pembrolizumab demonstrated a confirmed objective response rate of 48% compared with about 27% for pembrolizumab alone. About 14% of patients in the combination arm achieved a complete response, compared with no complete responses in the control arm, the company said.

Additionally, median progression-free survival stood at 9.6 months for the drug combination versus 4.9 months for pembrolizumab alone as of the data cutoff.

The drug combination showed particular efficacy in patients with HPV+ disease, which has prompted the company to expand the study by about 50 additional HPV+ oropharyngeal squamous cell carcinoma patients as it eyes a potential accelerated regulatory pathway.

The results "give us a strong rationale to expand the program, not only into HPV+ disease, but also to explore the potential of INBRX-106 in other highly immunogenic tumors and in combination with cancer vaccines," Chief Executive Mark Lappe said.