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.’ ”
Editor’s note: When a drug company creates a new cancer treatment, the treatment must be approved by the U.S. Food and Drug Administration (FDA) before doctors in the U.S. can prescribe it. An FDA approval for a new drug usually specifies the particular kinds of patients who are allowed to be treated. A drug called Imbruvica was recently FDA-approved for treating people with chronic lymphocytic leukemia (CLL) who have been previously but unsuccessfully treated with at least one other drug. Now, the FDA has also approved Imbruvica for people with CLL whose tumors have a genetic mutation called del 17p, as detected by molecular testing. People with this mutation are less likely to have success with standard CLL treatments, so Imbruvica could be a good alternative.
“The U.S. Food and Drug Administration today expanded the approved use of Imbruvica (ibrutinib) to treat patients with chronic lymphocytic leukemia (CLL) who carry a deletion in chromosome 17 (17p deletion), which is associated with poor responses to standard treatment for CLL. Imbruvica received a breakthrough therapy designation for this use.
“The FDA is also approving new labeling to reflect that Imbruvica’s clinical benefit in treating CLL has been verified. In February 2014, Imbruvica received accelerated approval to treat CLL based on its effect on overall response rate. New clinical trial results examining progression-free survival and overall survival have confirmed the drug’s clinical benefit.
“A type of non-Hodgkin lymphoma, CLL is a rare blood and bone marrow disease that usually gets worse slowly over time, causing a gradual increase in white blood cells called B lymphocytes, or B cells. The National Cancer Institute estimates that 15,720 Americans will be diagnosed and 4,600 will die from CLL in 2014. Imbruvica works by blocking the enzyme that allows cancer cells to grow and divide.”