What is the duration of immunotherapy for Merkel cell carcinoma?

From the Guidelines

Immunotherapy for Merkel cell carcinoma is typically continued until disease progression or unacceptable toxicity, with some patients receiving treatment for 6 months to 2 years or longer, as supported by the JAVELIN Merkel 200 trial 1. The duration of immunotherapy can vary depending on the individual patient's response and tolerance to treatment.

• Key factors influencing treatment duration include the stage of cancer, previous treatments, and the patient's overall health status.
• The most commonly used immunotherapy agents for Merkel cell carcinoma are pembrolizumab, nivolumab, and avelumab, which are typically administered intravenously every 2-3 weeks.
• For example, avelumab is often given at 800 mg IV every 2 weeks until disease progression or unacceptable toxicity, as shown in the JAVELIN Merkel 200 trial 1.
• Treatment decisions are individualized, and some patients with advanced disease may receive immunotherapy indefinitely as long as they continue to benefit and don't experience significant side effects.
• Immunotherapy works by enhancing the body's immune system to recognize and attack cancer cells, particularly effective in Merkel cell carcinoma which often has a viral origin (Merkel cell polyomavirus) making it more susceptible to immune-based treatments, as noted in the study 1.
• Regular monitoring through scans and clinical evaluations is essential to assess treatment effectiveness and manage potential immune-related adverse events, with toxicity profiles similar for avelumab, pembrolizumab, and nivolumab 1.

From the FDA Drug Label

Patients received BAVENCIO 10 mg/kg as an intravenous infusion over 60 minutes every 2 weeks until disease progression or unacceptable toxicity Patients with radiological disease progression not associated with significant clinical deterioration, defined as no new or worsening symptoms, no change in performance status for greater than 2 weeks, and no need for salvage therapy, could continue treatment.

The duration of immunotherapy with avelumab for Merkel cell cancer is until disease progression or unacceptable toxicity. Patients may continue treatment even with radiological disease progression if there is no significant clinical deterioration.

From the Research

Duration of Immunotherapy for Merkel Cell Cancer

• The duration of immunotherapy for Merkel cell cancer can vary, but according to the studies, treatment with pembrolizumab or avelumab can last for up to 2 years 2, 3.
• In the Cancer Immunotherapy Trials Network-09/Keynote-017 trial, patients received pembrolizumab for up to 2 years, with a median follow-up time of 14.9 months 2.
• The JAVELIN Merkel 200 study also reported that patients received avelumab until confirmed disease progression, unacceptable toxicity, or withdrawal, with a median follow-up of 54.3 months 4.
• The real-world clinical outcomes with avelumab in patients with Merkel cell carcinoma treated in the USA reported a median duration of avelumab treatment of 13.5 months, with 42% of patients still receiving avelumab by the end of follow-up 5.

Factors Associated with Response and Survival

• Baseline factors such as Eastern Cooperative Oncology Group performance status of 0, greater percent tumor reduction, and low neutrophil-to-lymphocyte ratio were associated with response and longer survival 3.
• Completion of 2 years of treatment was also associated with improved outcomes 3.
• PD-L1 status did not correlate with overall response rate, progression-free survival, or overall survival, but there was a trend toward improved progression-free survival and overall survival in patients with PD-L1-positive tumors 2, 4.

Overall Survival and Progression-Free Survival

• The 24-month overall survival rate was 68.7% in the Cancer Immunotherapy Trials Network-09/Keynote-017 trial, and the median overall survival time was not reached 2.
• The 3-year overall survival rate was 59.4% for all patients and 89.5% for responders in the Three-year survival, correlates and salvage therapies in patients receiving first-line pembrolizumab for advanced Merkel cell carcinoma study 3.
• The 4-year overall survival rate was 38% in the First-line avelumab treatment in patients with metastatic Merkel cell carcinoma: 4-year follow-up from part B of the JAVELIN Merkel 200 study 4.