Combination of Radiation Therapy and Immunotherapy Shows Promise for Patients with Locally Advanced Head and Neck Cancers

The findings of a new phase II trial show that the combination of radiation therapy and immunotherapy resulted in encouraging survival outcomes and acceptable toxicity for patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Findings will be presented at the 2020 Multidisciplinary Head and Neck Cancers Symposium, taking place February 27-29 in Scottsdale, Arizona.

In this single-arm trial, researchers recruited 29 patients with HNSCC. The population of interest would have ideally received the drug cisplatin with their radiation but were ineligible for platinum chemotherapy. Patients were treated with three cycles of pembrolizumab and concurrent radiation therapy over six weeks, followed by three additional cycles of the immunotherapy drug.

With a median follow-up of 21 months, the rates of one-year progression-free and overall survival were 76% [95% CI 56-88] and 86% [67-95], respectively. Estimated two-year PFS was 71% [49-84] and estimated two-year OS was 75% [51-88]. For patients with p16+ oropharynx cancer, the one-year PFS and OS rates were 88% and 94%, respectively; for the other patients, the rates were 58% and 75%, respectively.

 

“If you look back to the historic studies, radiation alone often cures patients with this disease. Some of the first patients treated with pembrolizumab for recurrent/metastatic cancer are still alive many years out, with no evidence of disease,” said lead author Dr. Jared Weiss, MD, an associate professor of medicine at the University of North Carolina Lineberger Comprehensive Cancer Center in a press release. “And so, our concept was that, in addition to whatever synergy the immunotherapy might provide with radiation, we also conceived of it in a more straightforward way as a ‘second shot on goal’ toward cure.”

Dr. Weiss cautioned that findings need confirmation in a randomized trial before the combination is recommended to patients. He¬†will present “Progression-free survival, overall survival and immunophenotyping outcomes for patients with stage III-IV head and neck cancer and cisplatin contraindication treated with definitive radiotherapy plus pembrolizumab” during the symposium’s Oral Abstract Session.