A genetic risk-stratified, randomized phase 2 intergroup study of fludarabine/antibody combinations in symptomatic, untreated chronic lymphocytic leukemia (CLL): Results from Cancer and Leukemia Group B (CALGB) 10404 (Alliance).

7503Background: Prior to use of novel targeted agents for CLL, debate existed regarding the best chemoimmunotherapy regimen to build upon in patients (pts) with non-del(11q) disease. The role of lenalidomide (L) was also not defined. CALGB 10404 was a randomized phase 2 study addressing these questions. Methods: Pts with untreated CLL requiring therapy were randomized to treatment with fludarabine + rituximab (FR), FR + 6 monthly consolidative treatments of L (5 mg days 1-21/28 x 1 then 10 mg days 1-21/28 x 5) (FR+L), or FR + cyclophosphamide (FCR). Based on pretreatment central interphase cytogenetic screening, pts with del(11q22.3) in at least 20% of cells were excluded from the primary analysis, testing whether 2-year progression-free survival (PFS) rate was improved in non-del(11q) pts within each arm. A target accrual of 103 non-del(11q) pts per arm provided at least 84% power to detect an increase in 2-year PFS rate from 60% to 73%; the critical value was 69% using a single stage design and type I e...