Posted: Monday, March 28, 2022
Karen Dybkær, BSc, MSc, PhD, of Aalborg University, Denmark, and colleagues investigated whether longitudinal flow cytometry–based monitoring of measurable residual disease (flow-MRD) may predict disease progression earlier and with higher sensitivity than biochemical assessments in patients with multiple myeloma in complete remission. The results from the Nordic Myeloma Study Group (NMSG) substudy of the EMN02/HO95 trial, which were published in BMC Cancer, may help to guide treatment decisions and tailor therapeutic strategies.
“Flow-MRD is a sensitive method for longitudinal monitoring of MRD dynamics in patients with multiple myeloma in complete response,” the investigators commented. “Increasing MRD levels precedes biochemically assessed changes and is an early indicator of subsequent clinical [disease] progression.”
Nordic patients with newly diagnosed multiple myeloma who underwent bone marrow aspiration for confirmation of complete response were eligible for enrollment. To identify and enumerate residual malignant plasma cells, the investigators performed a flow-MRD assessment of bone marrow samples.
The investigators compared MRD dynamics with biochemically assessed changes in the serum-free light chain and M component. A total of 20 patients who achieved a complete response or a stringent complete response during the observation period underwent at least three sequential flow-MRD assessments. Disease progression in the bone marrow was reported in six of these patients; this flow-MRD positivity preceded biochemically assessed and clinical disease progression by a mean of 5.5 and 12.6 months, respectively. The mean doubling time for malignant plasma cell expansion was 1.8 months, and the minimal malignant plasma cell detection limit was 4 × 10–5.
Disclosure: The study authors reported no conflicts of interest.