Time to AML progression. Results are presented for the safety population: (A) by randomized treatment group, (B) by cytogenetic response (complete + partial) in patients randomized to lenalidomide (LEN), and (C) by a landmark (6-month) analysis of AML-free survival by RBC-TI for ≥ 8 weeks in patients randomized to LEN. The placebo group includes 56 patients (83.6%) who had not achieved at least minor response by week 16 and were therefore crossed over to lenalidomide 5 mg.