Final analysis of the RESONATE-2 study: up to 10 years of follow-up of first-line ibrutinib treatment for CLL/SLL
Jan A. Burger, Paul M. Barr, Tadeusz Robak, Carolyn Owen, Alessandra Tedeschi, Anita Sarma, Piers Patten, Sebastian Grosicki, Helen O. McCarthy, Fritz Offner, Edith Szafer Glusman, Cathy Zhou, Anita Szoke, Lynne Neumayr, James P. Dean, Paolo Ghia, Thomas J. Kipps
Abstract
ABSTRACT: With up to 10 years of follow-up, we report results from the final analysis of RESONATE- 2, a phase 3 study of first-line ibrutinib vs chlorambucil for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Patients aged ≥65 years with previously untreated CLL/SLL without del(17p) were randomly assigned to receive either single-agent ibrutinib (420 mg/d; n = 136) or chlorambucil (0.5-0.8 mg/kg; ≤12 cycles; n = 133). With a median follow-up of 9.6 years in the ibrutinib arm, the median progression-free survival (PFS) was 8.9 years (95% confidence interval [CI], 7.0 to not estimable [NE]) vs 1.3 years (95% CI, 0.9-1.6) for the chlorambucil arm. Among patients with unmutated immunoglobulin heavy chain variable (uIGHV), del (11q), mutated TP53, or complex karyotype, the median PFS was 8.4 years (95% CI, 6.8 to NE) with ibrutinib and 0.7 years (95% CI, 0.4-1.2) with chlorambucil. Median overall survival (OS) with ibrutinib was not reached. The most common adverse events (AEs) of any grade included diarrhea (52%), fatigue (41%), cough (39%), nausea (32%), arthralgia (31%), peripheral edema (31%), and hypertension (30%). During the entire study period, 34 of 136 patients (25%) had an ibrutinib dose reduction due to AEs; these AEs improved in 30 of 34 patients (88%). At study completion, 27% of patients remained on first-line ibrutinib treatment. This landmark RESONATE-2 study defines median PFS and demonstrates continued OS benefit of first-line ibrutinib treatment for patients with CLL/SLL, including those with high-risk genomic features. Sustained efficacy and tolerability of ibrutinib reemphasize the favorable benefit-risk profile. This trial was registered at www.ClinicalTrials.gov as NCT01722487/NCT01724346.