Targeted Therapy vs Chemoimmunotherapy for Treatment-Naïve CLL
Ibrutinib has a favorable benefit/risk profile and may potentially eliminate the need for chemoimmunotherapy in patients with treatment-naïve chronic lymphocytic leukemia (CLL), according to a recent study.
Chemoimmunotherapy and targeted therapy with single-agent ibrutinib are both considered effective first-line treatments for CLL. However, their outcomes have not been directly compared.
Tadeusz Robak, MD, PhD, Copernicus Memorial Hospital (Lodz, Poland), and colleagues conducted a cross-trial comparison of ibrutinib data from the RESONATE-2 phase III study—which was conducted in patients aged at least 65 years without del(17p) mutation—and chemoimmunotherapy data from published phase III studies in first-line treatment of CLL. Researchers assessed for progression-free survival (PFS), overall survival (OS), and safety data for both ibrutinib and chemoimmunotherapy.
The chemoimmunotherapy regimens included in the analysis were fludarabine plus cyclophosphamide and rituximab; bendamustine plus rituximab; obinutuzumab, chlorambucil and rituximab, and chlorambucil; and ofatumumab plus chlorambucil. Median follow-up across the studies and regimens ranged from 14.5 months to 37.4 months.
Results of the analysis were published in the American Journal of Hematology (online August 20, 2018; doi:10.1002/ajh.25259).
Dr Robak and colleagues reported that PFS appeared longer with ibrutinib compared with chemoimmunotherapy among all patients. OS was comparable, they noted. Relative to chemoimmunotherapy studies that excluded patients with del(17p) mutations or enrolled older and less-fit patients, PFS was favorable for ibrutinib in high-risk groups (ie, advanced disease, bulky lymph nodes, and unmutated IGHV status).
Grade 3 or higher infections ranged from 9% to 40% across chemoimmunotherapy regimens and was 25% with ibrutinib. Grade 3 or higher neutropenia ranged from 26% to 84% for chemoimmunotherapy regimens and was 12% with ibrutinib.
“Although definitive conclusions cannot be made due to inherent limitations of cross-trial comparisons, this report suggests that ibrutinib has a favorable benefit/risk profile and may potentially eliminate the need for chemotherapy in some patients,” authors of the study concluded. “Randomized, comparative studies are needed to support these findings.”—Zachary Bessette