Real-world assessment of ipilimumab plus nivolumab in anti-PD-L1/PD-1- refractory Merkel Cell Carcinoma

Abstract

Background and aims: Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine carcinoma. Immune checkpoint inhibitors (ICIs) have emerged as the new standard of care in the treatment of advanced MCC, offering durable clinical benefit. Currently, two ICIs targeting the PD-1/PD-L1 axis- avelumab, an anti-PD-L1 agent, and pembrolizumab, an anti-PD-1 agent- are approved by the U.S. Food and Drug Administration (FDA) for the treatment of advanced MCC. Despite these advances in effective treatment options, approximately 50% of patients with unresectable/locally advanced or metastatic MCC have primary or acquired resistance to ICIs.