Medline ® Abstract for Reference 54
of 'Treatment of relapsed or refractory chronic lymphocytic leukemia'
A phase 2 study of idelalisib plus rituximab in treatment-naïve older patients with chronic lymphocytic leukemia.
O'Brien SM, Lamanna N, Kipps TJ, Flinn I, Zelenetz AD, Burger JA, Keating M, Mitra S, Holes L, Yu AS, Johnson DM, Miller LL, Kim Y, Dansey RD, Dubowy RL, Coutre SE
Blood. 2015 Dec;126(25):2686-94. Epub 2015 Oct 15.
Idelalisib is a first-in-class oral inhibitor of PI3Kδthat has shown substantial activity in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). To evaluate idelalisib as initial therapy, 64 treatment-naïve older patients with CLL or small lymphocytic leukemia (median age, 71 years; range, 65-90) were treated with rituximab 375 mg/m(2) weekly×8 and idelalisib 150 mg twice daily continuously for 48 weeks. Patients completing 48 weeks without progression could continue to receive idelalisib on an extension study. The median time on treatment was 22.4 months (range, 0.8-45.8+). The overall response rate (ORR) was 97%, including 19% complete responses. The ORR was 100% in patients with del(17p)/TP53 mutations and 97% in those with unmutated IGHV. Progression-free survival was 83% at 36 months. The most frequent (>30%) adverse events (any grade) were diarrhea (including colitis) (64%), rash (58%), pyrexia (42%), nausea (38%), chills (36%), cough (33%), and fatigue (31%). Elevated alanine transaminase/aspartate transaminase was seen in 67% of patients (23% grade≥3). The combination of idelalisib and rituximab was highly active, resulting in durable disease control in treatment-naïve older patients withCLL. These results support the further development of idelalisib as initial treatment of CLL. This study is registered at ClinicalTrials.gov as #NCT01203930.
University of California-Irvine, Irvine Chao Family Comprehensive Cancer Center, Orange, CA;