The United States Food and Drug Administration (FDA) has approved Keytruda® (pembrolizumab) for the treatment of advanced head and neck cancer that has stopped responding to platinum-based chemotherapy agents.1
Globally, head and neck cancer comprises the seventh most common type of cancer with an estimated 400,000-600,000 diagnoses every year. Head and neck squamous cell cancer (HNSCC) refers to head and neck cancer that originates in certain cells called squamous cells.
Metastatic or stage IV head and neck cancer refers to cancer that has spread from its site of origin to distant sites in the body. Overall survival at 5 years for patients diagnosed with metastatic head and neck cancer has remained at less than 4%, indicating a significant need in improved treatment for patients with this disease. Recurrent head and neck cancer refers to cancer that has recurred or progressed despite prior therapy.
Pembrolizumab belong to a new class of medicines called PD-1 inhibitors that have generated great excitement for their ability to help the immune system recognize and attack cancer. PD-1 is a protein that inhibits certain types of immune responses, allowing cancer cells to evade an attack by certain immune cells. Drugs that block the PD-1 pathway enhance the ability of the immune system to fight cancer.
Pembrolizumab, and another new PD-1 inhibitor, Opdivo® (nivolumab), work by blocking PD-1 and have demonstrated impressive activity in the treatment of melanoma, kidney, and lung cancers. These PD-1 inhibitors both appear to represent a significant advancement in the treatment of head and neck cancers. Pembrolizumab is also FDA approved in the United States for the treatment of certain types of lung cancers and melanoma. It is currently being evaluated in clinical trials for several different types of cancers.
Results from long-term follow-up data from the KEYNOTE-012 trial that led to the final approval of pembrolizumab in head and neck cancer were presented at this year’s annual meeting of the American Society of Clinical Oncology (ASCO).2 The trial evaluated the effectiveness of pembrolizumab in the treatment of 192 patients with metastatic or recurrent HNSCC.
- Anti-cancer responses were achieved in 18% of patients.
- 85% of anti-cancer responses lasted for at least 6 months, and 71% of anti-cancer responses lasted for at least one year.
- At 6 months after initiation of treatment with pembrolizumab, 58% of patients were alive, and 25% of patients were alive with no progression of cancer.
- At one year after initiation of treatment with pembrolizumab, 38% of patients were alive, and 17% of patients were alive with no progression of cancer.
- Patients who achieved anti-cancer responses with pembrolizumab had been followed for a median time of 12.5 months at the time of data collection. The median duration of time that anti-cancer responses continued had not yet been reached.
- Pembrolizumab was generally well tolerated.
This approval provides another treatment option for patients with advanced squamous cell head and neck cancer that has stopped responding to standard therapeutic options.
1) Merck. Corporate News. FDA approves Merck’s Keytruda® (pembrolizumab) for patients with recurrent or metastatic head and neck squamous cell carcinoma with disease progression on or after platinum-containing chemotherapy. Available at: http://www.mercknewsroom.com/news-release/prescription-medicine-news/fda-approves-mercks-keytruda-pembrolizumab-patients-recurr-0. Accessed August 8, 2016.
2) Mehra R, Seiwert T, Mahipal A, et al. Efficacy and safety of pembrolizumab in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC): Pooled analyses after long-term follow-up in KEYNOTE-012. Proceedings from the 201 annual ASCO meeting. Abstract #6012. Available at: http://abstracts.asco.org/176/AbstView_176_168015.html. Accessed June 7, 2016.
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