While therapeutic advances have improved survival of patients with follicular lymphoma (FL), it remains an incurable disease with inevitable relapse. This underscores the need for therapies and strategies to extend the duration of remission without significantly increasing toxicity and while maintaining quality of life. The role of maintenance therapies in FL was discussed in detail by Andrew D. Zelenetz, MD, PhD, of Memorial Sloan-Kettering Cancer Center and chair of the NCCN Guidelines Panel for Non-Hodgkin's Lymphomas during the NCCN 6th Annual Congress: Hematologic Malignancies™.
"Since follicular lymphoma responds well to therapy and is slow-growing, it is often thought of as a chronic disease. In the absence of symptoms, the disease has the potential to be managed through observation," said Dr. Zelenetz.
However, some patients are uncomfortable knowing that they have an active lymphoma that is not being addressed with therapy.
There are several approaches to post-remission therapy. Patients with FL who have responded to first-line therapy have the option of being observed or treated with consolidation therapy. Phase III studies have demonstrated that consolidation with radioimmunotherapy (FIT trial) or rituximab (Rituxan®, Genentech BioOncology and Biogen Idec) maintenance (PRIMA trial) are both effective and improve progression-free survival (PFS).
"Studies indicate that prolonged administration of rituximab significantly improves event-free survival in chemotherapy-naïve patients responding to rituximab-containing induction," said Dr. Zelenetz.
Event-free survival is defined as the time from first induction infusion to progression, relapse, second tumor, or death from any cause.
Rituximab has also been shown to be effective when given for a second time at the time of relapse, after patients had previously responded to rituximab. Whether rituximab maintenance treatment is superior to rituximab re-treatment (at the time of disease progression) has not yet been established.
"Past trials have shown significantly improved progression-free survival with rituximab maintenance, however no significant difference was seen in overall survival between the maintenance and re-treatment group," noted Dr. Zelenetz. "Ongoing research will continue to evaluate this approach."
Dr. Zelenetz emphasized that effect on OS is one of the most influential factors when weighing treatment decisions. However, phase III studies to-date have not demonstrated an OS benefit in patients with FL receiving post-remission therapy.
"The NCCN Guidelines include post-remission therapy (radioimmunotherapy consolidation or maintenance rituximab) as an option for patients responding to first-line chemoimmunotherapy," said Dr. Zelenetz. "Given the absence of an overall survival benefit, the NHL Guidelines Panel felt the decision to use post-remission therapy has to be made on an individualized basis after discussing the pros and cons with the patient."
Source: National Comprehensive Cancer Network