Memorial Sloan Kettering Cancer Center researchers have validated the real-world effectiveness of rituximab plus lenalidomide combination therapy in patients with relapsed/refractory indolent non-Hodgkin lymphoma (iNHL), according to findings published in Haematologica.
Clinical Outcomes and Response Rates
The study examined 84 patients with relapsed/refractory disease, comprising 69 patients with follicular lymphoma (FL) and 15 with marginal zone lymphoma (MZL). The chemotherapy-free combination achieved an impressive 82% overall response rate, with 52% of patients reaching complete remission. Notably, FL patients showed a higher complete remission rate of 55% compared to 40% in MZL patients.
Survival metrics proved equally encouraging, with a median progression-free survival of 22 months (95% CI, 19-36) and a two-year overall survival rate of 83% (95% CI, 74%-93%). For patients achieving complete response, the median duration of response extended to 46 months.
Treatment Protocol and Administration
The treatment regimen consisted of rituximab administered at 375 mg/m2 weekly for four weeks, followed by four additional doses over 28-day cycles. Lenalidomide was given orally at 20 mg doses for 21 days within each 28-day cycle, continuing for 12 cycles.
Safety Profile and Adverse Events
The safety analysis revealed manageable but significant adverse events. Neutropenia emerged as the most common side effect, affecting 48% of patients, followed by fatigue (45%) and thrombocytopenia (40%). Other notable adverse events included diarrhea (31%), constipation (30%), and skin rashes (27%). These safety concerns led to lenalidomide dose reductions in 45 patients.
Clinical Context and Disease Burden
The findings carry particular significance given that FL and MZL represent substantial portions of adult NHL cases, accounting for 22% and 7% respectively. This real-world validation supports the FDA's initial approval of the combination, which was based on the phase 3 AUGMENT trial where the treatment demonstrated superior progression-free survival compared to controls (39.4 vs 14.1 months).
Treatment Implications
The study results reinforce the combination's potential as a standard of care option for iNHL patients, particularly significant given the historical challenges in treating relapsed/refractory disease. The data suggests that while MZL patients with refractory disease may have lower complete response rates, the overall benefit-risk profile supports the combination's use across both FL and MZL populations.
