Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes. Chemoimmunotherapy has been long used as a treatment of CLL, but recent studies suggest the ibrutinib–rituximab to be more effective. This study aims to compare the effectiveness of ibrutinib–rituximab and chemoimmunotherapy treatments for chronic lymphocytic leukemia.

This is a randomized, phase-3 trial conducted on a total of 529 patients aged 70 years or younger with previously untreated CLL. The participants were randomly assigned to ibrutinib–rituximab for six cycles followed by ibrutinib, or six cycles of standard chemoimmunotherapy with cyclophosphamide, rituximab, and fludarabine. The primary outcome of the study was progression-free survival and overall survival.

At a median follow-up of 33.6 months, the progression-free survival was higher with ibrutinib–rituximab (89.4%) than chemoimmunotherapy (72.9%). The rate of overall survival was also higher with ibrutinib–rituximab (98.8%) than chemoimmunotherapy (91.5%). The incidence of adverse events was similar in the two groups (80.1% and 79.7%). Infectious complications were less common ibrutinib–rituximab (10.5%) than with chemoimmunotherapy (20.3%). 

The research concluded that ibrutinib–rituximab delivered better progression-free and overall survival than the standard chemoimmunotherapy. The incidence of adverse effects was comparable in the two groups, but the risk of infectious complications was higher with chemoimmunotherapy.

Ref: https://www.nejm.org/doi/full/10.1056/NEJMoa1817073