In Patients With Newly Diagnosed or Previously Treated Follicular Lymphoma Responding to Induction Therapy, Maintenance Rituximab Is Effective

ORLANDO, Fla.—Updated results from the phase 3b MAXIMA study provides additional support for utilizing rituximab maintenance every 2 months for 2 years following rituximab-containing induction therapy for patients with newly diagnosed or previously treated follicular lymphoma (FL).

Furthermore, maintenance rituximab was well tolerated, with little toxicity, and few infusion-related adverse events (AEs), and there was no apparent difference in tolerability when rituximab was administered as either standard or rapid infusion, reported Robin Foá, MD, Sapienza University, Division of Hematology, Rome, Italy, and colleagues.

The MAXIMA study is evaluating the safety of rituximab maintenance therapy in patients with treatment-naïve or previously treated FL responding to induction treatment. The effectiveness of rituximab maintenance therapy in terms of improvement of progression-free survival and overall survival, and rate of conversion from partial response (PR) to complete response/unconfirmed complete response (CR/CRu) while on maintenance therapy are also being confirmed, Dr. Foà noted in a poster presentation during the 52nd American Society of Hematology Annual Meeting and Exposition.

Patients from 211 centers in 24 countries who achieved a CR/CRu or PR following induction therapy with 8 cycles of a rituximab-containing regimen received maintenance treatment with rituximab (375 mg/m2) every 2 months for a maximum of 2 years. Rituximab could be administered at a standard infusion rate (>90 minutes) or as a rapid infusion (≤90 minutes), depending on the standard practice at each center.

A total of 545 patients responding to induction treatment were enrolled. Median age was 57 years (range, 29-86 years); 11.7% were >70 years. The majority of the patients (395, or 72.5%) were previously untreated. Of the 545 patients, 381 (69.9%) patients entered the study in CR/CRu after induction and 164 (30.1%) in PR. Of 381 patients with postinduction CR/CRu, 353 (92.7%) remained in CR/CRu during maintenance (progressive disease 7.1%; missing 0.3%). Of 164 patients achieving PR during induction, 11 patients (6.7%) converted to CR/CRu during maintenance.

The majority of patients (n=407; 74.7%) completed the full course of maintenance therapy. For those who did not complete rituximab maintenance (n=137), reasons for premature discontinuation were disease progression (58 patients), treatment toxicity (16), voluntary withdrawal (11), death (5), and other (47).

In the safety population (n=534), 52 infusion-related AEs occurred in 31 patients (5.8%); the most commonly reported AEs were hypotension (5 patients), pyrexia (3), hypertension (3), headaches (3), insomnia (2) and erythema (3). No differences in infusion-related AEs were observed by infusion schedule; AEs occurred with 0.9% of standard infusions and 0.5% of rapid infusions Table 1.

Most infusion-related AEs were grade 1 (42/52). One infusion-related serious adverse event (SAE), a grade 4 cerebrovascular accident, was reported. Other AEs were observed in 336 patients (62.9%); the majority were grade 1/2. Grade 3, 4, and 5 AEs occurred in 86 (16.1%), 30 (5.6%), and 9 patients (1.7%), respectively. Rituximab-related AEs were rare, occurring in 57 patients (10.7%) and accounting for only 6.1% (105/1721) of all AEs.

The most common rituximab-related AEs were infections, occurring in 22 patients (4.1%). Two grade 5 rituximab-related AEs were reported: 1 liver disorder and 1 cerebral hemorrhage. A total of 141 SAEs occurred in 104 patients; of these, only 19 events in 15 patients were deemed to be related to rituximab. The most common rituximab-related AE was pneumonia, with 3 events reported.

Off Label Use: Rituximab is broadly approved for the treatment of FL, however the specific use and therapeutic lines may represent some off-label use.