Ipilimumab therapy in advanced mucosal melanoma cases yields mixed outcomes

Treatment with ipilimumab can lead to robust antitumor outcomes, though patients with advanced mucosal melanoma typically show minimal overall response rate. The findings are part of a multicenter, retrospective study, led by Richard D. Carvajal, M.D., of Memorial Sloan-Kettering Cancer Center, New York, in collaboration with researchers from Dana-Farber Cancer Institute and Massachusetts General Hospital, Boston.

At 12 weeks, researchers looked at radiographic tumor response, overall survival and toxicity in 33 patients who were given single-agent ipilimumab treatment. Every patient had the following diagnosis: unresectable or metastatic melanoma of primary mucosal origin; 76 percent had previous systemic therapy for metastatic disease. A total of 25 patients had a median of four doses of ipilimumab, 3 mg/kg (range, two to eight doses), and 24 percent had a median of four doses of ipilimumab 10 mg/kg (range, two to 17 doses). Adverse events most often reported were rash (six patients), diarrhea (three patients), and one case each of thyroiditis, hepatitis and hypophysitis.

For the 30 patients who were assessable, radiographic measurement at 12 weeks showed one complete response (CR), one partial response (PR), and six stable disease cases. Overall response rate was 6.7 percent. The patient who achieved CR was 87 years at time of treatment and received ipilimumab as first-line treatment for metastatic disease. The median overall survival for all patients was 6.4 months.

“It is clear now that immunological-checkpoint blockade can result in durable clinical benefit in a number of different tumor types, however, the benefit rates may differ,” Dr. Carvajal said in a statement.

The study was published online May 28 in The Oncologist.