Combination of Ibrutinib, Rituximab Induced Responses in High-Risk CLL

Editor’s note: This article discusses the results of a clinical trial—a research study with volunteer patients. The goal of the trial is to test a new treatment for high-risk chronic lymphocytic leukemia (CLL). The treatment combines two drugs, ibrutinib and rituximab. Patients participating in the trial have had promising responses to the treatment. Further studies will continue to evaluate the new treatment.

“Patients with high-risk chronic lymphocytic leukemia demonstrated encouraging rates of objective response and durable remission after treatment with ibrutinib plus rituximab, according to results of a single-center phase 2 study.

“Jan A. Burger, MD, PhD, associate professor in the department of leukemia at The University of Texas MD Anderson Cancer Center, and colleagues assessed the activity and safety of ibrutinib (Imbruvica; Pharmacyclics, Janssen), a Bruton’s tyrosine kinase inhibitor, in combination with the chimeric monoclonal antibody rituximab (Rituxan; Genentech, Biogen Idec) in 40 adults with high-risk CLL.

“All patients either experienced short PFS — defined as less than 36 months — after first-line chemoimmunotherapy, or they demonstrated high-risk cytogenetic abnormalities, such as deletion 17p, deletion 11q or TP53 mutation…

“ ‘From this study, can we state that the time for ibrutinib monotherapy is over, and that combination with anti-CD20 antibodies the preferential treatment partner, as is the case for idelalisib (Zydelig, Gilead)?’ Ghia wrote. ‘Despite [these] promising results, we will probably need to wait. Short follow-up of only 18 months makes it difficult to ascertain whether an actual benefit in PFS or OS exists when compared with the monotherapy regimen. The clinical advantage of adding a second drug (rituximab) needs to be consistently proven because of the relevant economic consequences: The additional cost of combinations might jeopardize the overall sustainability of future treatments.’ ”