Outcomes Research in Review

AUGMENT: Lenalidomide/Rituximab vs Placebo/Rituximab in Relapsed or Refractory Indolent Lymphoma



Applications for Clinical Practice

Therapy for relapsed and refractory indolent B-cell lymphomas continues to evolve. While chemotherapy remains an effective option, immunomodulation using non-chemotherapeutic intervention has emerged as an attractive strategy. The AUGMENT trial further solidifies adoption of the non-chemotherapy doublet option of rituximab/lenalidomide based on the premise of immunomodulation. Both the agents have been commercially available for more than a decade and are being used for other indications beyond the study population for this trial.

Based on the AUGMENT and MAGNIFY trials, lenalidomide combined with rituximab was approved by the Food and Drug Administration for use in relapsed and refractory follicular or marginal zone lymphomas soon after the AUGMENT study results were published. The recommended lenalidomide dose for both lymphomas is 20 mg once daily orally on days 1 to 21 of repeated 28-day cycles for up to 12 cycles.

The evidence from this trial has yielded what is likely to be a practice changing regimen, with R2 replacing single-agent rituximab for treating follicular lymphoma in the second line or beyond. The response rates and PFS periods were slightly lower in MZL. R2 offers advantages associated with a chemotherapy-free regimen and improved PFS. Also, in the AUGEMENT trial the secondary and exploratory endpoints of time to next therapy, overall response rates, and overall survival rates were improved in patients treated with R2.

Practitioners may choose lenalidomide plus rituximab over rituximab alone based on the AUGMENT study. When considering this regimen, several points should be kept in mind. A very careful selection of patients would be prudent, considering that the study’s follow-up of less than 4 years is short for a disease with long overall survival rates. The study was not powered to compare overall survival benefit. Also, practitioners are reminded to limit the use of lenalidomide to a maximum of 12 months, with planned interruptions and 8 doses of rituximab, replicating the trial schema. Additionally, as per the clinical trial design, the regimen is not intended for rituximab-refractory patients. Patients with MZL constituted only 18% of the study, and conclusions of superiority in this subgroup were not statistically significant. Lenalidomide is not approved for other indolent B cell lymphoproliferative malignancies, such as small lymphocytic lymphoma and chronic lymphocytic leukemia. The conclusion of the published study abstract suggests acceptable use in recurrent indolent lymphomas, but no such conclusion can be made due to lack of inclusion of all indolent lymphoma subtypes in this study.

Longer-term use of lenalidomide has been associated with a marginally increased risk of secondary hematologic malignancies in patients with multiple myeloma who were prescribed lenalidomide maintenance therapy for up to 2 years following high-dose chemotherapy and autologous hematopoietic stem cell transplant.9 Interestingly, in the AUGMENT study and other trials using lenalidomide/rituximab, no significant increase in secondary hematologic malignancies has been reported. The absence of prior myeloablative chemotherapy and a shorter duration of use (1 year) in this group of patients may be factors in why no additional risk of secondary hematologic malignancies was observed. Longer-term follow-up may be needed to evaluate this risk.

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