Insights From: Michael L. Wang, MD University of Texas MD Anderson Cancer Center
Michael L. Wang, MD: If we have a high-risk patient, the patient will finish Nordic therapy, and we’re going to send the patient home without MRD testing. That’s our usual standard practice. But in the future, we will measure MRD, and if this high-risk patient, although they received intensive therapy, happens to be MRD-positive, we’re not going to send the patient home because they still have tumor to be killed. We’re going to use a different methodology, such as ibrutinib, acalabrutinib, venetoclax, Revlimid (lenalidomide), or bortezomib, to kill the MRD so the patient’s progression free survival, overall survival, or remission rate will be prolonged. MRD is like a riddle. It guides us and can guide our therapy. So, MRD should be used after finishing any therapy, especially when the patient achieved complete remission. It should be universally used.
MRD after induction therapy, so far, could not change therapy for mantle cell lymphoma or for any lymphoma. Induction therapy is usually followed by chemotherapy consolidation. So far, we cannot use MRD to change that therapy, but MRD is more useful after finishing all the therapies.
How do we take advantage of MRD to guide our maintenance therapy? Without MRD, without a good readout screen, we are blinded. We threw maintenance therapy, expensive antibody therapies, and expensive bottles of therapy to everybody. Not only is it waste of money, but it also causes a lot of side effects and destroys quality of life. But if we declare the MRD as negative, we don’t need to use maintenance therapy. We only need to apply maintenance therapies when MRD becomes positive in the future. Maybe they will never become positive. Maybe they will become positive after 10 years. But if you are using maintenance therapy, then that’s a waste of time, in my opinion. So, MRD shouldn’t guide maintenance therapy. It should guide initiation, the duration of therapy, and re-initiation of maintenance therapy. That’s why MRD is so exciting. That’s why it’s in the future. Because it will guide our therapy so we do not waste too many drugs that we don’t have to give to the patients, and it will save their quality of life and some money as well.