Two clinical studies suggest that the novel agent ibrutinib shows real potential as a safe, effective, targeted treatment for adults with chronic lymphocytic leukemia (CLL) and for patients with mantle cell lymphoma (MCL). The study was published in the New England Journal of Medicine with an accompanying editorial. Both studies, co-led by researchers at The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC - James) and at MD Anderson Cancer Center, were published in the Journal's June 19, 2013 online edition.
Chronic Lymphocytic Leukemia and Ibrutinib Results from the phase Ib/II trial showed an overall response rate (complete and partial) of 71 percent. At 26 months the estimated progression-free survival rate was 75 percent and overall survival was 83 percent. "Essentially all CLL patients respond well to ibrutinib, which lacks many of the side effects of chemotherapy and frequently produces long-lasting remissions even in patients with high-risk genetic lesions," says study co-leader John C. Byrd, MD, director of the division of hematology and a CLL specialist at the OSUCCC - James.CLL is the most common form of leukemia with an estimated 15,000 American diagnosed annually. It is a cancer of B cells, which are a major component of the immune system along with T cells. Ibrutinib (PCI-32765) is the first drug designed to target Bruton's tyrosine kinase, a protein essential for CLL-cell survival and proliferation. Ibrutinib kills malignant B cells but has little effect on healthy T cells - unlike other CLL therapies. This leaves an important arm of the immune system largely intact, enabling patients to remain healthier during treatment.