Rituximab maintenance no help in relapsed diffuse large B-cell lymphoma
Last Updated: 2012-10-26 16:10:27 -0400 (Reuters Health)
By Robert Saunders
NEW YORK (Reuters Health) - After high-dose chemo and autologous stem-cell transplant for relapsed CD20-positive diffuse large B-cell lymphoma (DLBCL), maintenance with the anti-CD20 monoclonal antibody rituximab does not improve event-free survival, researchers say.
Not only did rituximab not prevent relapse in their international trial, but it was associated with higher toxicity. "Therefore, this treatment is not recommended in relapsed DLBCL," the researchers concluded in their report online Monday in the Journal of Clinical Oncology.
"Opposite of what was observed in follicular lymphoma, the efficacy of rituximab in DLBCL is limited and may even decrease due to prior exposure and drug resistance," lead author Dr. Christian Gisselbrecht commented in an email to Reuters Health.
Dr. Gisselbrecht, at Hopital Saint Louis in Paris, France, and colleagues explain that the standard approach to relapsed DLBCL is first salvage chemotherapy. Responders may then go on to consolidation with high-dose chemotherapy, followed by autologous stem-cell transplantation.
In the current study -- prompted by some encouraging results of phase II studies -- 242 such patients were randomly assigned post-transplantation to receive rituximab every two months or to observation alone for one year. Median follow-up was 44 months.
Four-year event-free survival -- i.e., freedom from progression, relapse, new treatment, or death from any cause -- was 52% in the rituximab group and 53% in the observation group, the team found.
Furthermore, after day 100, rituximab was associated with a 15% higher rate of serious adverse events, most of which were infections.
"One of the unexpected findings in this study was an apparent benefit for women submitted to rituximab maintenance," Dr. Gisselbrecht pointed out in his email. "Is this effect by chance? Or is it related to other mechanisms such as a lower clearance of rituximab? In that case, dose modifications could be recommended but more investigations are warranted."
Overall, however, he and his colleagues conclude that patients like those in this study require innovative approaches to treatment. "Obviously, there is a need for new drugs which can be used safely after transplantation," Dr. Gisselbrecht said. "Unfortunately, most of the new drugs in development are until now more active in low grade lymphoma."
J Clin Oncol 2012.
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