Among patients with multiple myeloma (MM) receiving continuous lenalidomide maintenance, the risk of progression is lower for those with persistent minimal residual disease (MRD) than for those who lose MRD negativity, according to results published in The Lancet Haematology.
Researchers conducted a single-arm, phase 2 trial (ClinicalTrials.gov Identifier: NCT02538198) to evaluate longitudinal changes in MRD status and their association with progression-free survival (PFS) in patients with MM who received lenalidomide maintenance for up to 5 years.
The study enrolled 108 patients, and 100 of them were evaluable for PFS. The median follow-up for these patients was 40.7 months, and the median PFS was not reached. The 5-year PFS was 64%.
There were 103 patients who had MRD assessed at baseline (within a median of 14 days from the start of lenalidomide treatment). MRD was assessed annually for up to 5 years, and 62 patients remained on maintenance at the data cutoff.
At the start of maintenance, 44 patients were MRD negative, and 59 were MRD positive. Over the entire follow-up period, 45 patients had sustained MRD negativity, 8 converted from MRD positive to negative, and 10 converted from MRD negative to positive.
At 2 years, patients who had lost MRD negativity were more likely to progress than patients with sustained MRD negativity (hazard ratio [HR], infinite; P <.0001) and those with persistent MRD positivity (HR, 5.88; P =.015).
The rate of serious adverse events (AEs) was 18%. The most common grade 3 or higher AEs were decreased lymphocyte count (44%) and decreased neutrophil count (44%).
One on-study death, due to sepsis and heart failure, was considered unrelated to lenalidomide.
“We see here that longitudinal assessments of residual disease in the bone marrow provide additional prognostic resolution in the evolving risk of progression,” the study authors wrote. “Early intervention should be investigated for patients with loss of MRD negativity. Sustained MRD positivity is not categorically an unfavorable outcome and might portend prolonged stability of low-level disease.”
Disclosures: This research was supported by Celgene and Memorial Sloan Kettering Cancer Center. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Diamond B, Korde N, Lesokhin AM, et al. Dynamics of minimal residual disease in patients with multiple myeloma on continuous lenalidomide maintenance: a single-arm, single-centre, phase 2 trial. Lancet Haematol. 2021;8(6):e422-e432. doi:10.1016/S2352-3026(21)00130-7