A phase 3, randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of idelalisib in combination with rituximab for previously treated indolent non-Hodgkin lymphomas (iNHL).

TPS8617 Background: PI3K-delta is critical for activation, proliferation and survival of B cells and plays a role in homing and retention in lymphoid tissues. PI3Kδ signaling is hyperactive in many B-cell malignancies. Idelalisib is a first-in-class, targeted, highly selective, oral inhibitor of PI3Kδ that reduces proliferation, enhances apoptosis, and inhibits homing and retention of malignant B cells in lymphoid tissues (Lannutti et al, 2011). Phase 1 trials demonstrated that idelalisib is highly active in pts with heavily pretreated iNHL: pts experienced reductions in disease-associated chemokines, profound and rapid reductions in lymphadenopathy, and durable clinical benefit with acceptable safety profile (de Vos et al, 2011). Methods: 375 pts with previously treated iNHL, who have measurable lymphadenopathy, have received prior anti-CD20-antibody-containing therapy, and who have iNHL that is not refractory to rituximab (R) are randomized in a 2:1 ratio into Arm A or Arm B. In Arm A, pts receive idela...