Conversion to MRD positivity within 10 years of diagnosis conferred inferior overall and progression-free survival in a cohort of patients with multiple myeloma who had achieved bone-marrow MRD negativity following autologous stem cell transplantation (ASCT) and maintenance combination therapy. MRD conversion occurred in 39% of patients and correctly predicted relapse in 70%. Conversion predicted clinical relapse by a median of 1 year. The study was published in Blood Advances on February 8, 2022.

The analysis examined data for 568 consecutive patients treated since 2010 at the University of Arkansas for Medical Sciences. Bone-marrow multicolor flow cytometry assessment was performed at the start of therapy before transplantation, every 3 to 6 months during the first 2 years after transplantation, and then every 6 to 12 months depending on whether patients were still on maintenance therapy. The median number of MRD assessments was 15 per patient.

Median follow-up from diagnosis was 9.9 years.

The highest risk of MRD conversion occurred during the first 5 years after treatment. Patients with conversion during the first 3 years had inferior overall and progression-free survival compared with patients who had sustained MRD negativity. The median time to MRD conversion was 6 years from ASCT. Most patients (76%) showed MRD conversion within 10 years of their initial diagnosis. Among patients who remained MRD negative at 10 years, the subsequent risk of conversion was 31%.

“MRD conversion was strongly associated with increased risk of relapse, whereas sustained MRD negativity predicted for freedom from relapse,” wrote first author Meera Mohan, MD, and colleagues. Now at the Medical College of Wisconsin, Mohan led the study while completing her fellowship training at the University of Arkansas for Medical Sciences.

• Mohan M, Kendrick S, Szabo A, et al. Clinical implications of loss of bone marrow minimal residual disease negativity in multiple myeloma. Blood Adv. 2022;6(3):808-817. doi:10.1182/bloodadvances.2021005822

Tags: MRD, multiple myeloma, transplantation, Cellular therapy, Positivity, cell therapy, PFS, inferior, OS, conversion