A new immunotherapy treatment, MK3475, known as pembrolizumab, from Merck has proved effective in some patients with advanced head and neck, according to the early findings of a study presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
The findings were presented by Tanguy Seiwert, MD, the associate director of the Head and Neck Cancer Program and assistant professor of medicine at the University of Chicago.
In the phase IB study, a small number of patients with advanced head and neck cancer were treated with pembrolizumab, an anti-PD-1 antibody. The drug is part of an emerging class of medications that work by blocking the PD-1 protein, which is used by cancer cells to evade the body's immune system. When PD-L1 attaches to its receptor PD-1 on immune cells, tumors are able to hide from the immune system; drugs that target either PD-L1 or PD-1 inhibit this interaction.
In the study presented at the ASCO meeting, 56 patients with advanced head and neck cancer whose tumors were assessed as positive for PD-L1 expression were evaluable for treatment response with pembrolizumab; 20 of the patients tested positive for human papillomavirus (HPV). The early findings showed a best overall response rate of 20%, with 29% of patients having stable disease. Similar overall response rates were observed in HPV-positive and HPV-negative patients. Tumor shrinkage was demonstrated in 51% of evaluable patients who had measurable disease with one postbaseline scan.
The most common treatment-related adverse events included fatigue, pruritus, rash, nausea, myalgia, and decreased appetite, the researchers reported.
"Recurrent and metastatic head and neck cancer carries a very poor prognosis, and often is accompanied by poor quality of life and disfigurement. Additional treatment options are urgently needed," said Dr. Seiwert in a press release. "These early response data with pembrolizumab as monotherapy provide an encouraging proof of concept and support further study of this novel investigational immunotherapy in this hard-to-treat cancer type."
Merck is studying pembrolizumab for more than 30 types of cancers, as a standalone treatment and in combination with other drugs. Annual sales of pembrolizumab could reach $6 billion, according to industry estimates.
