Dr Fenske on the Benefit With Auto-HSCT in MRD-Positive Patients With MCL in First CR

"Based on this exploratory analysis, which admittedly has a relatively lownumber of patients, it did appear that the patients who converted to MRD negativity had better outcomes in terms of OS and PFS [with the omission of auto-HSCT], suggesting that MRD-positive patients may still benefit from autologous transplant."

Timothy S. Fenske, MD, MS, a medical oncologist and a professor of medicine at the Medical College of Wisconsin, discusses findings from an exploratory analysis of treatment outcomes with rituximab (Rituxan) in patients with mantle cell lymphoma (MCL) who achieved undetectable minimal residual disease (uMRD) vs those who remained MRD positive following consolidative autologous hematopoietic cell transplant (auto-HCT) from the phase 3 ECOG-ACRIN EA4151 trial (NCT03267433).

The ECOG-ACRIN EA4151 trial evaluated rituximab (Rituxan) with or without consolidative auto-HSCT in patients with MCL in their first complete response (CR)with uMRD. Initial data from the study were presented at the 2024 ASH Annual Meeting and showed that consolidative auto-HCT did not add to clinical benefit with rituximab for this patient population.

Fenske and colleagues also conducted an exploratory analysis examining outcomes based on post-transplant MRD status in arm C of the study. Arm C comprised patients who achieved a partial response (MRD-positive or -negative) or an MRD-positive CR and went onto the registration cohort to receive auto-HCT plus rituximab for 3 years (n = 49).

Patients who converted to uMRD6 post-transplant (n = 17) were shown to achieve better outcomes than those who remained MRD positive, with respective 3-year OS rates of 100% vs 63.6%, Fenske reports. Moreover, the 3-year PFS rates were similarly improved at 100% vs 48.8%, respectively, he notes. These findings suggest that MRD-positive patients may still derive benefit from auto-HCT, although the small subgroup size of this study limits definitive conclusions, Fenske cautions.

Overall, results indicate that MRD assessment can guide treatment decisions, potentially sparing uMRD patients from auto-HCT without compromising outcomes, as well as identifying MRD-positive patients who may benefit from intensified therapy, he concludes.