Can Exercise Boost the Efficacy of Rituximab in Treatment of CLL?

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Sessions of moderate-to-vigorous exercise may improve the efficacy of antibody therapies, such as rituximab, used to treat chronic lymphocytic leukemia (CLL), according to a recent study published by Collier-Bain et al in Brain, Behavior, and Immunity. The findings may demonstrate the potential of antibody therapies for certain types of cancers.


Patients with CLL are often treated with rituximab. The antibody therapy works by attaching itself to a specific protein on the surface of cancer cells, which natural killer cells are able to recognize and attack. 

Study Methods and Results

In the recent study, researchers assigned 20 patients (aged 45–82) with CLL who had not yet initiated treatment to partake in a 30-minute session of moderate-to-vigorous intensity cycling—with the goal of examining the impact of exercise on the efficacy of rituximab. The researchers then collected blood samples prior to, immediately following, and 1 hour after the exercise session.

Under ex vivo conditions, the researchers measured the quantity of natural killer cells present in each of the blood sample points and analyzed the cells’ ability to eradicate cancer cells with and without rituximab present. They noted that natural killer cells increased by 254%, and CLL cells transiently increased by 67% after exercise—making them potentially more susceptible to attack by natural killer cells and antibody therapy.

The researchers then isolated the natural killer cells and placed them in close contact with CLL cells for 2 hours ex vivo with and without rituximab. They discovered that when rituximab was present in the blood sample, the natural killer cells performed twice as effectively in killing the CLL cells in the samples collected immediately after the exercise sessions compared with collected prior to the exercise sessions.


“These findings show a potential benefit to patients undergoing a very particular type of treatment and could open up new avenues of research to determine whether exercise can improve the way other cancer treatments work,” highlighted co–study author James Turner, PhD, FHEA, of the University of Birmingham. 

“Cancer cells often try to hide in the body, but it seems that exercise works to move them out into the bloodstream, where they are vulnerable to the antibody therapy and the killing capabilities of natural killer cells,” emphasized senior study author John Campbell, PhD, BSc, of the University of Bath. 

The researchers indicated that the results of the study may also show the potential of exercise sessions in patients who have finished their treatment for leukemia and are being monitored for cancer recurrence. “Monitoring patients after treatment is complicated because if cancer cells remain or reappear, they are sometimes too low to detect, but a bout of exercise followed by a blood sample immediately afterwards could help to find them if they are hiding in the body,” stated lead study author Harrison Collier-Bain, PhD, of the University of Bath.

Although the findings were positive, larger-scale trials may be needed to elucidate the in vivo effects in a cohort of patients receiving rituximab prior to treatment for recommendations to be made.

“This study adds to a growing body of evidence showing that exercise can be helpful before, during, and after cancer treatment. We know that being physically active before and after treatment can help [patients with] cancer cope better with treatment, aid recovery, and improve mental well-being. It is interesting to see that exercise could also improve the efficacy of treatment for some types of [hematologic malignancies, yet] more research in a larger group of patients is needed,” underscored Caroline Geraghty, a senior specialist information nurse at Cancer Research UK. “Everyone has different needs and abilities, so it’s important [for patients to] discuss with [their physicians] what [types] of exercise would work best. We encourage all patients [with cancer] to seek their [physicians’] advice before starting a program of exercise before or after treatment, to make sure that the activities suggested are appropriate for them,” she concluded.

Disclosure: The research in this study was funded by Cancer Research UK. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.