Flavopiridol administered as a 24-hour continuous infusion in chronic lymphocytic leukemia lacks clinical activity

: Studies with flavopiridol have demonstrated that this agent has in vitro activity in chronic lymphocytic leukemia (CLL) and promotes apoptosis independent of p53 function or prior fludarabine exposure. Based upon this pre-clinical data, a phase I/II study of 24h flavopiridol was performed.

: Patients with previously treated CLL patients were enrolled on two sequentially performed cohorts of 13 patients. Patients in the first cohort received flavopiridol (80 mg/m(2) as a 24-h continuous infusion [24h CI]) every 2 weeks. Patients in the second cohort received flavopiridol (80 mg/m(2) as a 24h CI) for week 1 and then were dose escalated by 20mg/m(2) every 2 weeks to a maximal dose of 140 mg/m(2) in the absence of symptoms. Patients received up to 12 doses of therapy.

: Thirteen patients with fludarabine-refractory or intolerant CLL enrolled in each cohort. Patients received a median of five treatments in each cohort with only two patients completing all 12 courses of therapy. There were no partial or complete responses noted. Toxicity was manageable in most patients and included anemia, thrombocytopenia, infections, diarrhea, and fatigue.

: Flavopiridol as a 24-h continuous infusion has no clinical activity in relapsed, fludarabine-refractory CLL.