Objective: To explore the prognostic significance of the stage of reaching MRD-negative for patients with newly diagnosed multiple myeloma (NDMM) patients who received autologous hematopoietic stem cell transplantation (ASCT).

Methods: A retrospective analysis of 186 NDMM patients who received "induction therapy-ASCT-maintenance therapy" in our center and reached MRD-negative, according to the stage when the patient's MRD status turned negative (induction therapy, 3 months after ASCT, maintenance therapy) is divided into three stages, A, B, and C (Figure 1). We compared the clinical characteristics and prognosis of patients in the three stages.

Results: The median time to progress (TTP) of 186 patients was not reached, the median overall survival (OS) was 113.8 months, and the median follow-up time was 67.6 months; the number of cases in the three stages of A, B, and C was 73 (39.2%), 42 (22.6%), and 71 (38.2%), respectively (Figure 2). The median TTP of the patients in the three stages was not reached (P=0.013), and the median OS was not reached, not reached, and 71.2 months, respectively (P=0.026). Among the 124 standard-risk cytogenetics patients, the median TTP of the three stages of patients was not reached (P=0.121), and the median OS was not reached, not reached, and 99.6 months, respectively (P=0.091) (Figure 3). Among the 38 high-risk cytogenetics patients, the median TTP of patients in the three stages were unreached, 53.9 months, and 35.8 months (P=0.060), and the median OS was not reached, 71.2 months, and 60.2 months (P=0.625) (Figure 4). Among the 157 R-ISS Ⅰ-Ⅱ patients, the median TTP of the three stages was not reached (P=0.174), and the median OS was not reached, not reached, and 99.6 months (P=0.186) (Figure 5). Among 29 cases of R-ISS Ⅲ, the median TTP of the 3 stage patients was unreached, unreached, and 35.1 months (P<0.001), and the median OS was unreached, unreached, and 48.5 months, respectively (P=0.020) (Figure 6).

Conclusion: For the same patients with MRD negative, the prognosis of patients reaching MRD-negative at different stages is different. The stage of reaching MRD-negative can predict the prognosis of patients with R-ISS stage Ⅲ, but cannot predict the prognosis of patients with R-ISS Ⅰ-Ⅱ.

Figure 1
Figure 1.
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Disclosures

No relevant conflicts of interest to declare.

© 2021 by The American Society of Hematology
2021
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