P-170: Perspectives of single-center community hematologists/oncologists on minimal residual disease testing among patients with multiple myeloma

Introduction: Minimal residual disease (MRD) testing in multiple myeloma (MM) is an important tool for monitoring remission status and relapse. MRD negativity is an independent prognostic factor for progression-free survival (PFS) and overall survival (OS) in MM. However, optimal use of MRD testing remains unclear for healthcare professionals (HCPs). This survey explored hematologist/oncologist (hem-onc) perspectives on MRD testing, barriers to testing, and use of test results for clinical decision-making.

Methods: This was a prospective survey of hem-oncs practicing in a single community oncology practice with multiple locations throughout Florida, USA. To be eligible, hem-oncs must have been treating patients with MM and have used MRD testing for MM in their clinical practice. The survey questions captured hem-onc perspectives on drivers and barriers for MRD testing, patterns of MRD testing, and the use of MRD testing in treatment decision-making.

Results: A total of 22 hem-oncs were included in this study, with a median of 2.5 MRD tests ordered per provider between September 2019-October 2023; 86% had >5 years’ experience treating MM patients and 73% stated they were comfortable/very comfortable with MRD testing. The 3 most highly ranked reasons for conducting MRD testing were: to monitor patient remission status (91%), to detect recurrence of myeloma (59%), and to aid in treatment decision-making (50%). The 4 most frequently perceived barriers by hem-oncs for MRD testing were: logistics of sending samples to MRD testing facilities (96%), lack of insurance coverage (73%), lack of local testing facilities (68%), and unfamiliarity on next steps based on the results (32%). Most hem-oncs (82%) stated that they only conduct MRD testing if covered by insurance. Most hem-oncs considered MRD testing as essential for patients with high-risk cytogenetics (59%) or transplant eligible patients (55%), while 27% stated that all patients should receive MRD testing, regardless of disease characteristics. Hem-onc perspectives on next steps following a MRD negative test varied: 46% reported that they would not discontinue treatment, with most hem-oncs (86%) reducing the intensity of the regimen to a maintenance regimen. Following a MRD negative test, 36% of hem-oncs reported that they would discontinue treatment, with the most frequent (92%) reason being to give patients a treatment break. Most (77%) hem-oncs considered MRD negativity as an acceptable endpoint in clinical trials, while 18% and 5% preferred the use of OS and PFS, respectively.

Conclusions: Among hem-oncs who use MRD testing for MM, most were comfortable with MRD testing and used results to monitor disease and aid treatment decision-making. However, opinion on how MRD results should be used to inform clinical decisions was variable. Thus, there remains an opportunity to generate data on the clinical outcome of MRD negative results to inform the use of MRD testing by hem-oncs and guide them in clinical decision-making.