Minimal Residual Disease (MRD) is a highly sensitive measure used in myeloma trials to check for any remaining cancer cells after treatment. Even when traditional tests show remission, small numbers of myeloma cells can still linger, and these cells can eventually lead to relapse.

Achieving MRD negativity — meaning no detectable myeloma cells remain in the bone marrow or blood — indicates a deeper response to treatment. Sensitive methods like flow cytometry, next-generation sequencing (NGS), or polymerase chain reaction (PCR) can detect one cancer cell among 100,000 to 1,000,000 healthy cells, providing a thorough assessment of how well the treatment has worked.

Current Status as a Clinical Trial Endpoint

MRD negativity is an increasingly popular endpoint in multiple myeloma trials, often used alongside other measures like overall response rate (ORR) and progression-free survival (PFS).

Although traditionally a secondary or surrogate endpoint, MRD negativity is becoming recognized by the FDA and other regulatory bodies as a valuable measure for new treatment approvals, especially when waiting years for survival data isn’t practical. MRD’s potential as a primary endpoint is still being explored, but as of Fall 2024, it remains under consideration.

Learn more about its role and potential as an endpoint in the video below: 

Challenges of MRD Testing

While MRD testing is powerful, there are still some challenges. Standardizing MRD methods across trials is an ongoing process to ensure consistent and comparable results. Additionally, every patient’s myeloma is unique — some patients enjoy long remissions even without MRD negativity, while others who reach MRD negativity may still relapse.

Learn More

To learn more about MRD in multiple myeloma, check out our free HealthTree University Courses, taught by myeloma experts:

HealthTree University - Minimal Residual Disease (MRD)