MRD to Boost Access to Cancer Treatments, Obstacles Remain
Thanks to the new, innovative treatments for multiple myeloma (a type of blood cancer), patients can now live an average lifespan of 10 years compared to the two or three years back in 1995. Despite this success, the disease remains incurable; better therapies, and perhaps also a cure, are in development.
Each year, there are 32,000 Americans who are diagnosed with multiple myeloma, and so the demand for improved treatments is on the rise. But in order to provide better treatments, clinical trials must be done. The problem is that trials should run for eight years or so to determine whether experimental therapies can extend a patient’s survival. The much bigger problem — patients cannot afford to wait.
The good news is that a measure called minimal residual disease (MRD) could cut the waiting game short. Through this, scientists would be able to peek through the disease inside the patient’s bone marrow. Furthermore, MRD allows them to detect the cancer cell among thousands or even millions of healthy cells.
In the panel discussion hosted by Scientific American Custom Media and Amgen, Inc., it was concluded that MRD could definitely be used to speed up clinical trials and even drug development yet obstacles would still be present.
When getting approval for new therapies, researchers oftentimes use a surrogate endpoint — a measure that confirms the potential benefits or efficacy of the therapy being tested. In cancer, a shrunk tumor is a widely accepted surrogate endpoint; now, experts claimed that MRD could also be a good measure of efficacy for clinical trials. In fact, in 2018, the approval of a cancer drug was fast-tracked based on the measure of MRD.
Despite this, experts remained careful about using MRD as a surrogate endpoint due to validity reasons. According to Amgen’s executive director of regulatory affairs, Kathy Kross, multiple studies would be required to get a statistically valid proof that MRD is consistently predictive of overall survival; each study could last for years.
Patient advocates argued that people will die if they wait for the approval of new drugs and therapies based on many years of studies alone. Jeff Allen, president of Friends of Cancer Research, said the fact that MRD could predict survival in newly diagnosed multiple myeloma patients was already enough.
Meanwhile, there are already clinics that make use of MRD measurements to monitor multiple myeloma patients. Hopefully, other doctors would follow suit and use MRD as a basis of whether to pause, restart, or change treatments for patients — that is if clinical trials were already conducted. According to Sarah Holstein, an associate professor at the University of Nebraska Medical Center, plenty of clinical trials are already planned to provide high-standard proof of MRD’s benefits.