EFFICACY OF IDELALISIB AND RITUXIMAB IN RELAPSED/REFRACTORY CHRONIC LYMPHOCYTIC LEUKEMIA TREATED OUTSIDE OF CLINICAL TRIALS. A REPORT OF THE GIMEMA WORKING GROUP

Because the efficacy of new drugs reported in trials may not translate into similar results when used in the real-life, we analyzed the efficacy of idelalisib and rituximab (IR) in 149 patients with relapsed/refractory chronic lymphocytic leukemia treated at 34 GIMEMA centres. Median progression-free survival (PFS) and overall survival were 22.9 and 44.5-months, respectively; performance status (PS) ≥2 and ≥3 previous lines of therapy were associated with shorter PFS and OS. 48% of patients were on treatment at 12 months; the experience of the centres (≥5 treated patients) and PS 0-1 were associated with a significantly longer treatment duration (p=0.015 and p=0.002, respectively). TP53 disruption had no prognostic significance. The ORR to subsequent treatment was 49.2%, with median OS of 15.5 months and not reached in patients who discontinued, respectively, for progression and for toxicity (p<0.01). Treatment breaks ≥14 days were recorded in 96% of patients and adverse events mirrored those reported in trials. In conclusion, this real-life analysis showed that IR treatment duration was longer at experienced centres, that the ECOG-PS and ≥3 lines of previous therapy are strong prognostic factor and that the overall outcome with this regimen was superimposable to that reported in a randomized trial. This article is protected by copyright. All rights reserved.