Vincristine sulfate liposomes injection (Marqibo) in heavily pretreated patients with refractory aggressive non-Hodgkin lymphoma: report of the pivotal phase 2 study.

Background: Marqibo, a sphingosomal/cholesterol encapsulation of vincristine sulfate has targeted, increased, and sustained delivery of vincristine to tumor tissues. A phase 2, open-label, single-arm, and multinational study evaluated the efficacy and tolerability of Marqibo as a single agent in patients with multiply relapsed or refractory aggressive non-Hodgkin lymphoma (NHL).

Methods: Eligible patients had relapsed or refractory de novo or transformed aggressive NHL and prior treatment with at least 2 multiagent chemotherapy regimens. Marqibo was administered at 2 mg/m2, every 2 weeks, for a maximum of 12 cycles or until toxicity or disease progression.

Results: One hundred and nineteen patients were enrolled and treated on trial. Ninety-six had histological confirmed de novo (N=89) or transformed (N=7) aggressive NHL. Median number of cycles was 4 (median dose/cycle 4 mg). Overall response (CR and complete response unconfirmed and PR) was 25% (95% confidence interval [CI], 17, 35), CR and complete response unconfirmed confirmed by external reviewers was 5%. Median overall survival was 6.6 months (Kaplan-Meier estimate, 95% CI, 4.7, 9.8). Grade 3 of 4 neurotoxicity occurred in 32% of patients. All patients had prior neurotoxic agents, and 85% had baseline residual neuropathy symptoms (grades 1-2) from prior treatment.

Conclusions: Marqibo is an active agent in patients with heavily pretreated aggressive NHL, and tolerated at approximately twice the dose intensity of standard vincristine. Its activity supports further investigation as a substitution for vincristine in combination treatment of lymphoid disorders.