FROM HAEMATOLOGICA
Next-generation sequencing might be useful to monitor for minimum residual disease in multiple myeloma, based on the results of a pilot study of 27 patients.
Of study participants whose multiple myeloma at least partially remitted on therapy, 41% showed evidence of persistent circulating myeloma cells or cell-free myeloma DNA based on next-generation sequencing of the clonotypic V(D)J rearrangement, compared with 91% of nonresponders or progressors (P less than .001), reported Anna Oberle of University Medical Center Hamburg-Eppendorf, Hamburg, Germany, and her associates. The findings were published in Haematologica.
“Taken together, our pilot study gives valuable biological insights into the circulating cellular and cell-free compartments explorable by ‘liquid biopsy’ in multiple myeloma,” the investigators wrote. Levels of V(D)J-positive circulating myeloma cells and cell-free DNA might decline faster in response to effective therapy than the “relatively inert M-protein,” and might therefore be a better way to immediately estimate treatment efficacy or predict minimum residual disease negativity, they added (Haematologica. 2017 Feb 9. doi: 10.3324/haematol.2016.161414 ).
Novel multiple myeloma therapies are inducing deeper, longer responses, which highlights the need for minimum residual disease monitoring, the researchers said. Next-generation sequencing of the clonotypic V(D)J immunoglobulin rearrangement has shown promise but requires painful bone marrow sampling. A minimally invasive alternative is to monitor for circulating myeloma cells (cmc) or cell-free myeloma (cfm). To investigate the feasibility of this technique, the researchers used next-generation sequencing to define the myeloma V(D)J rearrangement in bone marrow and to track sequential peripheral blood samples from multiple myeloma patients before and during treatment. Next-generation sequencing was performed with an Illumina MiSeq sequencer with 500 or 600 cycle single-indexed, paired-end runs.
After treatment initiation, 47% of follow-up peripheral blood samples were positive for cmc-V(D)J, cfm-V(D)J, or both, the researchers said. They found a clear link between poor remission status assessed by M-protein based IMWG criteria and positive cmc-V(D)J sampling, with a regression coefficient of 1.60 (95% CI, 0.68 to 2.50; P = .002). Poor remission status was also associated with evidence of cfm-V(D)J (regression coefficient 1.49; 95% CI, 0.70 to 2.27; P = .001).
“About half of partial responders showed complete clearance of circulating myeloma cells-/cell-free myeloma DNA -V(D)J despite persistent M-protein, suggesting that these markers are less inert than the M-protein, rely more on cell turnover, and therefore decline more rapidly after initiation of effective treatment,” the researchers emphasized. Also, in 30% of cases, patients were positive for only one of the two V(D)J measures, suggesting that cfm-V(D)J might reflect overall tumor burden, not just circulating tumor cells, they added. “Prospective studies need to define the predictive potential of high-sensitivity determination of circulating myeloma cells and DNA in the monitoring of multiple myeloma,” they concluded.
Eppendorfer Krebs- und Leukämiehilfe e.V. and the Deutsche Krebshilfe funded the study. The researchers disclosed no conflicts of interest.
