A pilot study with vincristine sulfate liposome infusion in patients with metastatic melanoma.

Vincristine sulfate liposome infusion (VSLI) is a sphingomyelin/cholesterol liposome encapsulated formulation of vincristine that results in an extended drug circulation time and the potential for enhanced malignancy targeting, exposure, and anticancer activity. We assessed the safety and activity of VSLI in patients with metastatic melanoma. VSLI, to provide VCR 2.0 mg/m without dose capping, was infused over 1 h every 2 weeks (one cycle). Safety, tumor response, and survival were determined. Twenty-seven patients with metastatic melanoma of cutaneous (n=19), uveal (n=4), mucosal (n=1), and unknown (n=3) primary were treated. Twenty-five (93%) patients had received one or more prior lines of chemotherapy and/or immunotherapy; 14 (48%) had received a vinblastine-containing regimen. Hematologic adverse events (AEs) primarily manifested as grade 1/2 neutropenia. Nonhematologic AEs primarily consisted of gastrointestinal and constitutional symptoms of grade 1/2 severity. Grade 3 AEs included one case of paresthesia and four cases of constipation. The disease control rate in 26 evaluable patients was 31%. One complete (uveal melanoma metastatic to lung) and two partial responses (previously untreated cutaneous melanoma metastatic to the bone, brain, spleen and lung, and another with melanoma of unknown primary involving the lung, liver, and lymph node) were found. Five patients had stable disease. The median time to progression was 1.9 months. The median survival was 9.6 months with 30% of the patients alive at 1 year. VSLI was generally well tolerated and showed promising antitumor activity against metastatic melanoma and uveal melanoma in particular. A phase 2 trial to further elucidate the efficacy and safety of VSLI in metastatic uveal melanoma is ongoing.