Liposomal vincristine for the treatment of human acute lymphoblastic leukaemia in severe combined immunodeficient (SCID) mice

Non-obese diabetic NOD/SCID mice have been used to grow human leukaemia as a systemic disease. The animals were inoculated with leukaemic cells obtained from a 36-year-old male with early B-cell precursor acute lymphoblastic leukaemia and on day 15 were given the first of three weekly injections of 1 mg/kg vincristine or equimolar liposomal vincristine. The development of leukaemia in the mice was monitored by taking weekly blood samples and measuring the cell content by flow cytometry. The median time to 50% human cells in the peripheral blood of mice treated with free vincristine was 41 d from the start of treatment compared with 49 d for mice treated with liposomal vincristine (P < 0.01). The median day of death for mice treated with free vincristine was 47 d from the start of treatment and 57 d for mice receiving liposomal vincristine (P