What is the threshold for achieving minimal residual disease (MRD) negativity after treatment?
MRD measurement aims to detect any myeloma cells that remain in the body after a complete response is achieved following treatment. MRD tests can detect at least 1 myeloma cell in 100,000 healthy bone marrow cells (a threshold of 1 × 10-5) and other tests can detect 1 cell in a million (a threshold of 1 × 10-6). As an example, when you collect 100,000 bone marrow cells and you don’t find any myeloma cells with testing, you are considered MRD negative (this is a threshold of 10-5) and similarly if you don’t find any myeloma cells within one million bone marrow cells (this is a threshold of 10-6). Currently, a threshold of 10-5 is used to define MRD negativity in clinical studies and the FDA drug development process. Deeper thresholds like 10-6 are being used and reported in clinical studies, but in practice it might be difficult to get the one million bone marrow cells needed to test at this threshold.
Sometimes patients may receive a result that is difficult to tell whether they are MRD positive or not. These results are considered below the level of detection and even though the result may not be zero, it is still a very good result. Regardless of your MRD status, it is always best to discuss your MRD test results and what they mean with your doctor.
Are MRD results being used to guide treatment decisions?
MRD testing is far from an experimental test. Testing has been well-validated based on extensive data from clinical studies. However, basing treatment decisions on MRD test results is not routinely done, especially outside of the academic medical center setting. For example, it is unclear whether patients who are MRD positive should get more treatment, whether patients who go from MRD negative to MRD positive should get treatment before development of clinical symptoms, and whether patients who are MRD negative no longer need maintenance therapy. Several clinical studies are ongoing to determine how MRD results might be used to guide treatment in the future. However, MRD testing results do provide some level of information for the patient and the doctor about the trajectory of the disease. What this means is that MRD test results help to inform doctors if and how the number of myeloma cells has changed since a patient’s last MRD test (that is, did the number of cells go up, go down, or remain the same?). This information will help patients and their doctors understand how the amount of myeloma in a patient’s body may be changing over time. Be sure to ask your doctor to put your MRD test results, over time, into context for you and where you are in your myeloma journey.
Is MRD testing covered by insurance?
MRD measured by flow cytometry is usually covered by insurance because it is typically part of bone marrow biopsy testing. MRD measured by next-generation sequencing (that is, the ClonoSEQ assay developed by Adaptive Biotechnologies) is FDA-approved and is widely covered for patients on Medicare. Medicare covers clonoSEQ at 100% for multiple myeloma, and 90% of all patients pay $0 out of pocket. Patients will only receive a bill for unmet deductibles or coinsurance after the test is covered by insurance. Call the Adaptive Patient Support team at 1-855-236-9230 or visit Adaptive-Assist.com for 5-minute enrollment and rapid verification.
