Minimal Residual Disease Testing: A New Way Forward
There are two important news items to report this week. First, an article in Blood reports that current MRD testing for myeloma in the US is producing quite erratic results.
This disturbing assessment is made based upon a survey of 26 major institutions across the US. Key findings include variations in the number of cells checked after treatment, to see if myeloma cells are present, as well as wide variations in the methods used in the assessment of cells present.
So, if a patient goes to one center the test might show MRD negative, while to another--MRD positive! We know that the importance of this test is huge, and we need to clarify what it really means. New standardized criteria for MRD testing are definitely required.
The second news item is thus especially important as it is the breaking news from the first Black Swan Research Initiative Investigators Meeting that was held on October 25, 2013. I'm pleased to report that we are well on the way to consensus on how to assess MRD-Zero. Professors Alberto Orfao and Bruno Paiva from the University of Salamanca presented results of the new fully automated, sensitive, and standardized technique for MRD testing in myeloma as part of BSRI. The technique is flow cytometry, a method that truly provides a new way forward.
What this means is that a reliable test is now available to determine MRD-Zero, using the new flow methodology. This test will be the new response reference standard within many upcoming trials.
What does this mean for patients?
First, it means that a key first step in the Black Swan Research Initiative has been accomplished--and ahead of schedule. However, it does not mean that all patients should rush to get MRD testing yet! A battery of tests is under evaluation to determine the indicators of MRD status. They are:
- DNA testing is being assessed as another specific and very sensitive myeloma disease marker, and cross correlations between the flow and DNA tests are ongoing.
- In addition, imaging (PET/CT or whole body low-dose CT) is important to determine if low levels of disease are being missed, especially in soft tissue or any sites outside the bone marrow.
- The new Hevylite test is being studied as a more precise replacement for standard immunofixation (IFE) to determine if low levels of myeloma protein (M-protein) persist.
- Large database analyses are also underway to establish the meaning of achieving an MRD-Zero disease status. Correlations with patients who have been in complete remission for over 4 years (as long as > 25 years) have been carried out.
It will take time to standardize and validate MRD testing in myeloma in order to monitor response to treatment and push to achieve cure. The next step is integrating the agreed upon MRD testing protocol into upcoming trials.
This overview is just a glimpse of what is to come. There will be a full report from the Black Swan team very soon about the details of the new MRD flow test, followed by details about planned further studies and trials. Stay tuned!
Dr. Brian G.M. Durie serves as Chairman of the International Myeloma Foundation and serves on its Scientific Advisory Board. Additionally, he is Chairman of the IMF's International Myeloma Working Group, a consortium of nearly 200 myeloma experts from around the world. Dr. Durie also leads the IMF’s Black Swan Research Initiative®.