Real-world treatment outcomes in patients with metastatic Merkel cell carcinoma treated with chemotherapy in the USA

Aim: This retrospective study of patients in the USA with metastatic Merkel cell carcinoma (mMCC) aimed to assess patient responses to second-line and later (2L+) and first-line (1L) chemotherapy. Patients & methods: Out of 686 patients with MCC identified in The US Oncology Network, 20 and 67 patients with mMCC qualified for the 2L+ and 1L study, respectively; the primary analysis population was restricted to immunocompetent patients. Results: In the 2L+ primary analysis population, objective response rate (ORR) was 28.6%, median duration of response (DOR) was 1.7 months and median progression-free survival was 2.2 months. In the 1L primary analysis population, ORR was 29.4%, median DOR was 6.7 months and median progression-free survival was 4.6 months. Conclusion: The low ORR and brief DOR underscore the need for novel therapies.