In a significant advancement for the treatment of head and neck cancers (HNC), the FDA has approved a new first-line treatment for patients with metastatic or recurrent HNC. This treatment utilizes the immunotherapy drug pembrolizumab (Keytruda), which can be administered either alone or in combination with chemotherapy. This marks the first new first-line treatment approval for HNC in a decade, addressing the urgent need for more effective and less toxic treatment options.
Pembrolizumab works by blocking the expression of PD-L1, a protein that helps cancer cells evade the immune system. By inhibiting PD-L1, pembrolizumab enables the immune system to recognize and attack cancer cells. This approach has shown to dramatically improve survival rates, both in the short and long term, compared to the previous standard of care involving three chemotherapy drugs.
The approval of pembrolizumab was largely influenced by a large, international, randomized phase III clinical trial directed by Dr. Barbara A. Burtness, Professor of Medicine at Yale. The trial involved nearly 900 patients divided into three groups: one receiving pembrolizumab alone, another treated with pembrolizumab plus chemotherapy, and a third group receiving the older standard treatment of chemotherapy plus cetuximab.
Findings from the trial revealed that patients treated with pembrolizumab had significantly better outcomes. Specifically, among patients with higher levels of PD-L1, the addition of pembrolizumab to chemotherapy resulted in a median survival of 14.7 months, compared to 11 months for those on the standard regimen. Furthermore, the durability of the effect was notable, with 35% of pembrolizumab-treated patients still alive after two years, compared to 19% of those who received conventional chemotherapy.
Dr. Burtness emphasized the importance of early exposure to pembrolizumab, noting that it may sensitize tumors to subsequent therapies and lead to durable survival effects. The FDA's decision reflects these findings, allowing HNC patients with higher PD-L1 expression to be treated with pembrolizumab alone as a first-line monotherapy, and all patients, regardless of PD-L1 levels, to receive the drug in combination with chemotherapy as a first-line treatment.
In addition to this breakthrough, Dr. Burtness is leading further clinical trials exploring the use of pembrolizumab in radiotherapy-resistant HNC patients and investigating the combination of immunotherapy with an HPV vaccine. These ongoing studies aim to uncover even more effective treatment strategies for head and neck cancers, offering hope for improved outcomes and quality of life for patients.