Modified Delphi Method Identifies Consensus Areas for Routine Minimal Residual Disease Testing in Multiple Myeloma

Background: Despite evidence from clinical and real-world studies demonstrating a consistent association between minimal residual disease (MRD) negativity and improved survival in patients with newly diagnosed or relapsed/refractory multiple myeloma (MM), MRD testing has not been fully integrated into routine clinical practice. A paucity of data from clinical trials of MRD-directed therapy is a contributing factor. Until more data are available, consensus regarding the practical utility of MRD testing in MM established via a modified Delphi process can help guide clinical practice. Objective: To establish areas of consensus and non-consensus regarding the current utility of MRD status to assess and confirm response to MM therapy, and to provide guidance regarding its utility in disease management. Methods: The modified Delphi process, a systematic validated approach to gain consensus, is composed of two or more iterative rounds of surveys answered by a panel of experts. This expert Delphi panel comprised 61 practicing hematological oncologists from 14 European countries (Figure). A group of 11 advisors (within the panel) developed the survey questions and analyzed the results. Survey 1 assessed experts' opinions on and challenges associated with MRD testing in different clinical situations. Survey 2 further refined the use of MRD testing, methodologies, and frequency in different clinical settings using case studies. Consensus to an individual question was defined a priori as 75% agreement or disagreement by the panel. Of the 61 experts, most (87%) had treated ≥50 patients with MM in the 12 months prior to the study, and all had experience with MRD testing in MM in routine clinical practice and/or clinical trials. All members completed Survey 1, and 53 (87%) completed Survey 2. Results: The advisors determined that two rounds of surveys were sufficient for data interpretation. Only 64% of the Delphi panel felt suitably informed regarding the use of MRD testing in MM, and only half reported that MRD is covered in the treatment and/or prognostic guidelines that they use, suggesting that MRD-testing guidelines are limited. The panel reached consensus agreement that clinicians will benefit from more education/resources in the use of MRD testing to guide treatment decisions (92%) and guidelines on the use of MRD testing in routine MM care (75%). Panel consensus agreement was reached on MRD testing in routine care for patients who are transplant-eligible (TE), i