Phase I–II trial of VP‐16 in the treatment of acute nonlymphocytic leukemia and blast crisis of chronic granulocytic leukemia

VP‐16 was used to treat newly diagnosed elderly (⩾65 yr) patients with acute nonlymphocytic leukemia (ANLL) and patients with blast crisis of chronic granulocytic leukemia (BI‐CGL). Our pilot study indicated that VP‐16 160 mg/m² intravenously daily for 5 days was well tolerated and suggested a direct dose‐response correlation. Thirty additional ANLL patients and 11 CGL patients were studied. Among 26 evaluable ANLL patients, we observed ten responses (38%) (seven complete remission and three partial remission), but none of 11 patients with CGL in blast crisis had meaningful responses. In patients who responded to treatment, myelosuppression was always reversed by day 25. Stomatitis was the major nonhematologic toxicity and appeared more severe with advancing age. We conclude that VP‐16 is active against ANLL and is well tolerated at doses higher than have been previously described. It remains to be shown that the present schedule is superior to the intermittent high‐dose or continuous low‐dose infusion schedules, which have been recently described.