Liposome vincristine sulfate, also known as Marqibo was approved by the FDA in 2012. Vincristine is an anticancer alkaloid that binds to tubulin and interferes with cell division. Marqibo is vincristine encapsulated in sphingomyelin/cholesterol liposomes. Constipation, nausea, fatigue, diarrhea and insomnia are significant side effects. When administered to adult patients with Philadelphia chromosome-negative chronic myelogenous leukemia, Marqibo (2.25 mg/m2) induced a positive reaction in 35% of the patients. Liposomal vincristine offers other benefits, such as increased circulation time and low systemic toxicity.