MRD status was a “powerful predictor” of both progression-free survival (PFS) and overall survival (OS) among patients with multiple myeloma who had undergone autologous stem call transplantation (ASCT), in results from the phase 3 Myeloma XI trial that were presented at the International Myeloma Workshop in Vienna, Austria, in September.
MRD was assessed by flow cytometry 3 months post ASCT and 6 months later. Patients who were MRD negative at the first assessment experienced a 57% reduction in PFS events and a 47% reduction in the risk of death. At the second assessment, those who were MRD negative had a 79% reduction in PFS events and a 67% reduction in the risk of death. Sustained MRD negativity from the time of the first assessment to the time of the second assessment, or conversion to MRD negativity by the second assessment, were associated with the longest PFS and OS.
Also at 3 months post ASCT, patients were randomly assigned to lenalidomide maintenance or no maintenance therapy. Among patients who were MRD positive at randomization, 30% of those randomized to the maintenance group converted to MRD negativity at the second assessment, compared with 17% of those randomized to no maintenance therapy.
“At both [MRD assessment] time points, regardless of MRD status, lenalidomide maintenance was associated with improved PFS and OS, whilst high-risk molecular features were associated with adverse outcomes,” the investigators, led by Ruth de Tute, PhD, of the Institute for Cancer Research at the University of Leeds, UK, reported.