The immunotherapy pembrolizumab (Keytruda, Merck & Co) has been approved for use in the treatment of head and neck cancer by the US Food and Drug Administration (FDA).
The new indication is for use of pembrolizumab at 200 mg every 3 weeks in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) with disease progression during or after platinum-containing chemotherapy. The FDA granted an accelerated approval for this indication, which is based on tumor response rate and durability of response, and further proof of clinical benefit is required from confirmatory trials. Two large phase 3 trials are in progress.
The accelerated approval was based on results from the Keynote-012 trial, which showed an objective response rate (ORR) of 16%, complete response rate of 5%, and responses lasting for 6 months or longer observed in 82% (23/28) of the responding patients. The ORR and duration of response were similar regardless of human papillomavirus (HPV) status.
Immune-mediated adverse reactions seen with pembrolizumab include pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis, and if these reactions are severe, the drug should be withheld or discontinued and corticosteroids administered, says the manufacturer.
"Head and neck cancer is a complex disease that historically has been associated with high recurrence rates and poor long-term outcomes, highlighting the critical need for new treatment options," Tanguy Seiwert, MD, associate director of the Head and Neck Cancer Program and assistant professor of medicine at The University of Chicago, Illinois, commented in a company press release. The approval of pembrolizumab is "is an important step forward in treating this disease," he added.
Dr Seiwert presented initial results from the Keynote-012 trial last year at the American Society of Clinical Oncology meeting, when he described the efficacy seen as "remarkable."
The ORR seen with pembrolizumab is double that of cetuximab (Erbitux, Bristol Myers-Squibb/Eli Lilly), which is the only targeted therapy for these patients, said Dr Seiwert. In addition, he noted that the ORR with pembrolizumab was 27.2% in the 81 HPV-negative patients and 20.6% in the 34 HPV-positive patients. This is notable because there appears to be less efficacy with epidermal growth factor receptor inhibitors, such as cetuximab, in HPV-positive head and neck cancers, Dr Seiwert noted.
"We have high hopes that immunotherapy will change the way we treat head and neck cancer patients," he commented.