SWOG0919: a Phase 2 study of idarubicin and cytarabine in combination with pravastatin for relapsed acute myeloid leukaemia

Inhibition of cholesterol synthesis and uptake sensitizes acute myeloid leukaemia (AML) blasts to chemotherapy. A Phase 1 study demonstrated the safety of high dose pravastatin given with idarubicin and cytarabine in patients with AML and also demonstrated an encouraging response rate. The Southwestern Oncology Group (SWOG) trial, SWOG S0919, was a Phase 2 trial evaluating the complete remission (CR) rate in a larger number of patients with relapsed AML treated with idarubicin, cytarabine and pravastatin. This study closed to accrual after meeting the defined criterion for a positive study. Thirty-six patients with a median age of 59years (range 23-78) were enrolled. The median time from diagnosis to registration was 18months. Relapse status was first relapse, 17 patients (47%); second relapse, 15 patients (42%); third relapse, two patients (55%) and fourth relapse, two patients (55%). The response rate was 75% [95% confidence interval: 58-88%; 20 CRs, 7 CR with incomplete count recovery (CRi)], and the median overall survival was 12months. The P-value comparing 75-30% (the null response rate based on prior SWOG experience) was 3356x10(-4). Given the encouraging CR/CRi rate, this regimen should be considered for testing in a prospective randomized trial against best conventional therapy.