A dose escalation feasibility study of lenalidomide for treatment of symptomatic, relapsed chronic lymphocytic leukemia

Adequate dosing of lenalidomide in Chronic Lymphocytic Leukemia (CLL) remains unclear. This study determined maximum tolerated dose (MTD) in relapsed CLL patients (Cohort A) and patients achieving a partial response (PR) or better to recent therapy (Cohort B). Thirty-seven patients were enrolled. MTD was 2.5 mg followed by 5.0 mg continuous. In Cohort A, tumor flare grade 1-2 occurred in 15 patients (50%) and grade 3 in 1 patient (3%). Cohort A had 19 of 23 evaluable (83%) patients, 4 PR (17%) and 15 (65%) stable disease (SD), Cohort B had 6 of 7 patients (86%) with SD. Despite overall response rate not being high, many patients remained on therapy several months with SD.