Magnify: Phase Iiib Interim Analysis Of Induction R-2 Followed By Maintenance In Relapsed/Refractory Indolent Non-Hodgkin Lymphoma.

7513 Background: Standard treatment is lacking for patients with relapsed indolent NHL (iNHL). PI3K inhibitors reported a median PFS of < 1 y in R/R iNHL. The immunomodulatory agent lenalidomide shows enhanced activity with rituximab (ie, R2), which recently reported a 39.4-mo median PFS in R/R iNHL patients (AUGMENT; Leonard. ASH 2018:445). Methods: MAGNIFY is a multicenter, non-registrational phase IIIb trial in patients with R/R FL grade 1-3a and MZL designed to determine the optimal duration of lenalidomide. Lenalidomide 20 mg/d, d1-21/28 + rituximab 375 mg/m2/wk c1 and q8wk c3+ (R2) are given for 12c followed by 1:1 randomization in patients with stable disease or better to continued R2 vs rituximab maintenance. These analyses evaluate the primary endpoint of ORR by 1999 IWG criteria for induction R2 in efficacy-evaluable patients receiving ≥ 1 treatment with baseline/post-baseline assessments. Results: At a median 16.7 mo follow-up, 370 patients (80% FL grade 1-3a; 20% MZL) were enrolled with a median age of 66 y, 83% stage III/IV disease, and a median of 2 prior therapies (95% prior rituximab-containing). Efficacy-evaluable patients showed a 73% ORR and 45% CR (Table). Median TTR was 2.7 mo, median DOR was 36.8 mo, and median PFS was 36.0 mo. 142 of 370 patients have been randomized and entered maintenance. The most common all-grade AEs were 48% fatigue, 40% neutropenia, 35% diarrhea, 30% nausea, and 29% constipation. Grade 3/4 AE neutropenia was 34%; all other grade 3/4 AEs were < 6%. Conclusions: R2 therapy is active with a tolerable safety profile in patients with R/R FL and MZL, and in patients refractory to rituximab. Clinical trial information: NCT01996865. [Table: see text]