Statins do not interfere with rituximab treatment for lymphomas, study finds

December 9, 2008

Statins, drugs widely prescribed to lower cholesterol, do not interfere with a commonly used medication to treat lymphomas, according to a Mayo Clinic study presented today at the
50th Annual Meeting of the American Society of Hematology (http://www.hematology.org/meetings/2008/) in San Francisco. In fact, statins may slow the progression of certain types of lymphoma.

The study focused on the impact of statin use on outcomes of patients with two most common lymphoma types, diffuse large B-cell lymphoma and follicular lymphoma. Both are cancers of the immune system. Examples of commonly used statins in the U.S. include Lipitor, Zocor, Parvachol, Lescol, Mevacor and Crestor.

Rituximab (Rituxan), a monoclonal antibody, is often used alone or in conjunction with chemotherapy drugs to treat lymphomas. When administered to patients with lymphoma, rituximab attaches to CD20, a protein found on lymphoma cells. Addition of rituximab to chemotherapy improves outcomes in many lymphoma types.

A laboratory-based study by Winiarska and colleagues published this year in The Public Library of Science Medicine journal suggested that statins may inhibit rituximab binding to CD20. "That finding raised questions about maintaining or stopping cholesterol treatment with statins for patients with lymphoma," says Grzegorz Nowakowski, M.D., Mayo Clinic hematologist and lead researcher on the Mayo study.

"One in five lymphoma patients take cholesterol-lowering statins; this corresponds to the potential for thousands of patients at risk of getting less or ineffective treatment due to statin interference with therapy," says Dr. Nowakowski. "In our prospectively followed cohort of patients, we found that statins did not interfere with rituximab and in some cases, may offer a benefit."

The Mayo Clinic study included:

-- 228 patients with diffuse large B-cell lymphoma, an aggressive form of the disease. Twenty-two percent of this group was taking statins when they started treatment for lymphoma.

-- 293 patients with follicular lymphoma, an often indolent and slowly progressive form of the disease. Nineteen percent of patients were taking statins.

Statins did not impinge treatment effectiveness for either group of patients. For patients with diffuse large B-cell lymphoma, statin use did not influence outcomes. Those with follicular lymphoma who took statins fared better than patients who didn't. At two years, 80 percent of those taking statins had no progression or re-treatment for their cancer versus 69 percent of those not taking statins. Dr. Nowakowski said these are early results and further validation in additional cohorts of patients is needed. This positive effect was seen regardless of the treatment approach for the lymphoma. Treatments included observation only, rituximab alone or rituximab in combination with chemotherapy medications.

Dr. Nowakowski said that while oncologists at times recommend simplifying a patient's drug regimen before starting chemotherapy, many patients simply remain on statins during treatment. "We were concerned that these patients may be at risk of receiving less effective treatment due to statin interaction with rituximab. These results can provide reassurance to oncologists and their patients that statins will not reduce the effectiveness of rituximab and may in fact improve outcomes of some patients with lymphomas," he says.

Source: Mayo Clinic