Lenalidomide, rituximab (R 2 ), and ixazomib for frontline treatment of high risk follicular and indolent non-Hodgkin lymphoma.

Lenalidomide and rituximab (R 2 ) is an effective frontline treatment for patients with indolent B-cell non-Hodgkin lymphoma (iNHL). We investigated the safety and efficacy of addition of the proteasome inhibitor ixazomib to R 2 for treatment of iNHL through a phase I/II clinical trial for high-risk patients. Twenty patients were enrolled, 18 were treated. The target dose of ixazomib 4 mg weekly was achieved during dose escalation. The most common treatment-related adverse events (AEs) were low grade gastrointestinal, rash, neuropathy, and myalgia/arthralgia. There were 33% grade 2 and 17% grade 3 infections. With median follow-up of 5.2 years, four patients discontinued treatment due to lymphoma progression. Best overall response rate (ORR) was 61.2% [55.6% CR, 5.6% PR): 22.2% had stable disease and 16.7% had disease progression. Kaplan-Meier estimates of progression free and overall survival (OS) were 73% and 87% at 36 months, respectively. R 2 can safely be combined with ixazomib for treatment-naïve iNHL patients.