Study summary
Pembrolizumab as first treatment shrank about half of advanced Merkel cell cancers, often for years
49%had their tumors shrink
What was tested
Pembrolizumab, an immunotherapy, as the first drug treatment for Merkel cell carcinoma that had spread or come back. No comparison group.
What they found
- Tumors shrank in 49%, and 12 people had their cancer disappear.
- Responses lasted a median of 39.8 months.
- Half were alive at 2 years.
- Serious side effects occurred in 24%; one person died of a nerve condition caused by treatment.
What it means
Long follow-up confirms immunotherapy as the first treatment for advanced disease.
Last reviewed 2026-11-14 by the Find a Trial editorial team.
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