Response rates with PD-1 inhibitors in patients with acral and mucosal melanomas were similar to previously reported rates in patients with cutaneous melanoma, a study published in the journal Cancer has shown.1
PD-1 inhibitors are indicated for the first-line therapy of patients with metastatic cutaneous melanoma; however, the efficacy of these agents has not been well studied in melanomas arising from acral and mucosal surfaces.
For the retrospective study, investigators analyzed data from 60 patients with advanced acral and mucosal melanoma who received nivolumab or pembrolizumab as part of expanded access programs or published prospective trials. Of the 60 patients, 85% had received prior therapy, including 77% who had previously received ipilimumab.
Results showed that the objective response rate was 32% (95% CI, 15-54) in the 25 patients with acral melanoma and 23% (95% CI, 10-40) in the 35 patients with mucosal melanoma.
At a median follow-up of 20 months in the acral melanoma group and 10.6 months in the mucosal melanoma group, the median progression-free survival was 4.1 months and 3.9 months, respectively.
Of note, 3% of patients discontinued immunotherapy due to treatment-related toxicity.
The findings ultimately suggest that PD-1 inhibitors should be considered for routine use in patients with acral and mucosal melanomas. Further investigation is warranted to determine the mechanisms of response and treatment resistance in these melanoma subtypes.
1. Shoushtari AN, Munhoz RR, Kuk D, et al. The efficacy of anti-PD-1 agents in acral and mucosal melanoma. Cancer. 2016 Aug 17. doi: 10.1002/cncr.30259. [Epub ahead of print]