Andrew D. Zelenetz, MD, PhD, Chair of the Non-Hodgkin Lymphoma Guideline Panel of the National Comprehensive Cancer Network (NCCN) and former Chief of the Lymphoma Service at Memorial Sloan-Kettering Cancer Center, New York, put the latest maintenance trials into perspective for The ASCO Post.

“There are two ways to interpret the data. Both studies support the evidence of a prolongation in progression-free survival with maintenance rituximab (Rituxan). The SAKK trial did not meet its primary endpoint, but when investigators corrected for early failures that had nothing to do with maintenance, it did meet the endpoint of an improvement in progression-free survival. In PRIMA, this was very highly significant,” he noted.

Most Important Endpoint

“There are those who argue that an improvement in progression-free survival is important, but most of us believe that the most important endpoint in follicular lymphoma is making patients live longer. We proved we can do this by adding rituximab to chemotherapy, so to those who say we cannot improve survival—that’s not true, we can,” Dr. Zelenetz said. In the current maintenance trials, overall survival was not improved.

Dr. Zelenetz emphasized the mature data from PRIMA—6 years of follow-up—and the overlapping of the survival curves between the maintenance and observation arms. “There’s absolutely no difference, and no trend. There’s nothing to suggest the curves were separating, even with follow-up at 6 years,” he said.

He concluded that if overall survival is the most important hard endpoint for this disease, maintenance does not improve that. The reason for that is the fact that retreatment at progression is very effective, he maintained.

Maintenance an Option, Not a Mandate

He also pointed out that the NCCN states, because of the lack of a survival advantage, maintenance rituximab is not the standard of care, despite the fact that some lymphoma specialists do consider it virtually mandatory.

“I think the position is much more nuanced,” he added. “Maintenance should be an option. I tend to try to find the middle ground. I tell patients why it might be right for them, or why it might not be right.”

While there are some exceptions, Dr. Zelenetz usually recommends observation to patients. He estimates that about 30% of his patients opt for maintenance therapy—for example, those who have a compelling reason to delay the time to next treatment, such as mothers with school-age children. “It needs to be a case-by-case discussion between the physician and patient,” he said. “For some, it’s a legitimate option.”

Disclaimer: Dr. Zelenetz is on the advisory board of and receives research support from Genentech/Roche and is a consultant for Hospira, Dr. Reddy’s Laboratories, and Celgene.