While minimal residual disease (MRD) is being used to assess response to treatment in multiple myeloma (MM), the level of risk a patient has
can make a big different in how well MRD works as a prognostic indicator, according to 2 abstracts presented at the 2019 American Society of Clinical Oncology Annual Meeting.
In one abstract, researchers analyzed a single institution’s experience with assessing MRD and describe the impact of depth, duration, and direction of response on prognosis.1
The analyzed 181 patients with MM; 126 of whom were newly diagnosed and 55 were in at least a second line of therapy. A total of 398 MRD samples were analyzed.
Overall, 34% (43) of the newly diagnosed patients achieved MRD negativity (MRD-) at least once and these patients had prolonged progression-free survival (PFS) compared with patients who were MRD positive (MRD+). Among the patients receiving at least a second line of therapy, 38% (21) achieved MRD-, and they also had prolonged PFS compared with patients who were persistently MRD+.
The researchers also found that disease burden was an indicator with patients having a better prognosis if they were MRD- or MRD+ at a low level compared with those who had higher disease burdens.
Based on the findings, the authors concluded that MRD assessment is as successful in the real world as it is in clinical trials.
“This study lends support to the concept of MRD-driven decision-making and helps validate the relevance of MRD,” they wrote.
However, in a second abstract, researchers found that MRD assessment is not as powerful of a prognostic indicator in patients with high-risk MM compared with patients who have standard risk.
They evaluated 136 patients at MD Anderson Cancer Center who had undergone MRD testing after initial therapy or autologous stem cell transplant (ASCT). During follow up (median of 14 months), PFS and overall survival were “significantly worse” in high-risk patients versus standard risk. High-risk patients had statistically worse PFS than standard-risk patients regardless of MRD status. In addition, the researchers found that MRD status had no impact on overall survival in either group.
“Genetic abnormalities (FISH/GEP) remain a powerful prognostic indicator for myeloma regardless of MRD status,” they wrote. “For newly diagnosed myeloma patients treated with novel triple initial therapy and frontline ASCT, achieving MRD negative status didn’t mitigate the poor prognosis outcomes of [high-risk MM].”
1. Martinez-Lopez J, Kuan Wong SW, Shah N, et a. Minimal residual disease clinical monitoring and depth of response in multiple myeloma. Presented at: 2019 American Society of Clinical Oncology Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract: 8026.
2. Kunacheewa C, Patel KK, Lee HC, et a. Correlation of minimal residual disease negativity (MRD-) with prognosis in high-risk myeloma (HRM). Presented at: 2019 American Society of Clinical Oncology Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract: 8024.