Anas Younes, MD: There’s evidence that consolidation or maintenance therapy, or extended rituximab therapy, after R-chemotherapy and most recently after obinutuzumab chemotherapy, can prolong the progression-free survival and the time to next treatment. And we’re starting to see, probably, hints that it may improve survival. It would still require longer term follow-up. But up until recently, all we knew was that the addition of 2 years of rituximab, and most recently obinutuzumab after R- or G-chemotherapy, can prolong the progression-free survival and time to next treatment. It became an option for physicians and patients to elect to get the extended course with the maintenance or elect to just get the R-chemotherapy or G-chemotherapy, wait until recurrence, and use different regimens.

These are usually discussions with the patient about the data, lack of survival advantage—at least, strong survival advantage, for now—and whether or not they want to commit themselves to 2 additional years of treatment, coming in every 2 months and disrupting their lifestyle if they’re busy traveling and so forth, in exchange for delayed time to next treatment. Or do they want just to take a break and come back when the disease recurs? So, it’s a discussion. There’s really no guidance right now to how can you select patients for maintenance.

Bruce Cheson, MD: In 2007, when we updated the response criteria for non-Hodgkin’s as well as Hodgkin’s lymphoma, PET scans were still relatively in their infancy. Those criteria PET scans were considered the gold standard for response assessment, but primarily for large cell lymphoma and Hodgkin’s lymphoma, because those were the histologies for which we had the data. Since that time, there have been several studies clearly showing benefit using PET scans in follicular and other histologies of non-Hodgkin’s lymphoma. Judith Trotman, for example, published a paper in which she took 3 studies—2 of which were retrospective analyses, 1 of which was a prospective analysis of the role of PET scans in restaging follicular lymphoma—and showed that patients who were PET-negative after treatment had a significantly longer progression-free survival and, in fact, overall survival than those who were PET-positive. So, PET/CT scans are now, according to the Lugano classification, a standard for restaging all FDG-avid lymphomas, which includes follicular lymphoma. That’s for restaging. There is not a clear role for surveillance scans once the patient is already in complete remission or, for most patients, even a partial remission. Those should be based on clinical parameters and patients’ signs and symptoms of the disease.

Transcript Edited for Clarity