The authors of a study published in Blood Advances reported that for patients with mantle cell lymphoma (MCL) who are eligible for autologous stem cell transplantation (ASCT), high rates of remission could be achieved with induction therapy using rituximab/bendamustine (RB) in addition to rituximab/cytarabine (RC).

The study involved a pooled analysis of data for a total of 88 patients from 2 clinical trials (ClinicalTrials.gov Identifiers: NCT01661881, NCT02728531) and an off-trial population (47 patients). One trial (23 patients) evaluated sequential use of RB/RC, while the other trial (18 patients) involved RB/RC given in alternating cycles. Multiple efficacy outcomes and safety were evaluated in this analysis.

Overall, 92% of the patients in this analysis completed a full 6 cycles of induction therapy, with 84% receiving consolidative ASCT. A total of 87 patients could be evaluated for response. Following induction, the overall response rate was 97%, with a 90% complete response rate.

The median length of follow-up was 33.0 months. The 3-year PFS rate was 83% (95% CI, 75%-93%), and the 3-year OS rate was 92% (95% CI, 85%-98%).

The timing of minimal residual disease (MRD) assessment varied across a subset of patients who were tested. The investigators reported that MRD-negativity tended to be durable after ASCT. Among 17 patients who had received peripheral blood MRD testing 2 or more times following ASCT, only 2 patients showed post-ASCT MRD-positivity after previously demonstrating MRD-negativity, with 1 of these patients developing MRD after a prolonged period of negativity.

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Grade 3 or 4 adverse events were reported for clinical trial participants in this study, among which the most common were lymphopenia in 88% of patients, thrombocytopenia in 85%, and neutropenia in 83%.

“In our pooled analysis, RB/RC induction followed by ASCT was associated with high rates of durable remissions in transplant-eligible patients with MCL,” the study authors wrote in their report.

Reference

Merryman RW, Edwin N, Redd R, et al. Rituximab/bendamustine and rituximab/cytarabine induction therapy for transplant-eligible mantle cell lymphoma. Blood Adv. 2020;4(5):858-867.