(HealthDay News) -- A new drug that targets interactions with the tumor microenvironment promotes remission in patients with relapsed chronic lymphocytic leukemia, according to a study published online June 19 in the New England Journal of Medicine.
As part of a phase 1b-2 study, John C. Byrd, M.D., from The Ohio State University in Columbus, and colleagues treated 85 patients with relapsed chronic lymphocytic leukemia with ibrutinib (PCI-32765) orally once a day, where 51 patients received 420 mg and 34 received 840 mg.
The researchers found that both groups had the same overall response rate of 71 percent. An additional 20 percent of the 420-mg group and an additional 15 percent of the 840-mg group had a partial response with lymphocytosis. The responses were independent of clinical and genomic risk factors. The estimated rate of progression-free survival was 75 percent and the estimated rate of overall survival was 83 percent at 26 months. Toxicity was largely grade 1 or 2, including diarrhea, fatigue, and upper respiratory tract infection.
"Ibrutinib was associated with a high frequency of durable remissions in patients with relapsed or refractory chronic lymphocytic leukemia and small lymphocytic lymphoma, including patients with high-risk genetic lesions," Byrd and colleagues conclude.
The study was partially funded by Pharmacyclics and Janssen Biotech, the manufacturers of ibrutinib.