Sunesis’s anti-cancer drug shows clinical activity in leukemia patients

The trial showed that SNS-595 was generally well tolerated with anti-leukemic clinical activity when administered either once- or twice-weekly at biologically active doses to patients with relapsed or refractory acute leukemias. Results showed that 12 of 30 patients (40%) who received doses of SNS-595 of 50mg/m2 or greater on a weekly dose schedule achieved bone marrow blast reductions to less than 5%, and four of these 12 patients achieved either complete remission (CR), complete remission without platelet recovery (CRp) or complete remission with incomplete recovery of normal hematopoietic blood elements (CRi).

In the twice-weekly dosing cohort, anti-leukemic activity was observed among two out of 14 patients (14%) who received doses of 40mg/m2 or greater, including one complete remission. In both arms of the study, SNS-595’s anti-cancer activity correlated with sustained exposure to drug above a threshold plasma concentration for at least 20 hours per week of active treatment. At the maximum-tolerated-dose, this threshold was exceeded on average in both dosing schedules.

Overall, SNS-595 was generally well tolerated, with a dose-limiting toxicity of reversible Grade 3 to Grade 4 oral mucositis.