Minimal residual disease (MRD) testing is used to understand the depth of response, but currently the data at Emory are not used to make treatment decisions, said Ajay Nooka, MD, MPH, FACP, associate professor, Winship Cancer Institute.
Minimal residual disease testing is used to understand the depth of response, but currently the data at Emory are not used to make treatment decisions, said Ajay Nooka, MD, MPH, FACP, associate professor, Winship Cancer Institute.
Can you discuss the process that led to adoption of the ClonoSeq test at Emory?
In myeloma, we have used these response assessments for testing myeloma with the capillary-based techniques for over 70, 80 years. These techniques were initially developed in the 1930s, I believe, and we started using them in myeloma for response assessment in the 1970s and 1980s. If you look, through the course of time, we have new advances, new treatments, giving us such unprecedented results that what we're using today probably is not sufficient in terms of the capillary-based techniques. We needed novel techniques to measure the depth of response. How much of the residual disease is remaining after a specific treatment?
With the new treatments—like quadruplet treatments with dara plus KRd [daratumumab, carfilzomib, lenalidomide, and dexamethasone] or dara plus VRd [daratumumab, bortezomib, lenalidomide, and dexamethasone]—we're seeing these MRD-negative rates in the range of 70%, 80%, which means most of these patients have achieved a stringent complete response and the disease is lurking benign. We need a test to evaluate how much of that measurable disease is remaining and how to quantify that. That's where the ClonoSeq comes into play.
Right now, we know that the depth of response matters. The deeper the response is, the longer the remission periods are. Can we leverage them to use for a completely different purpose? That's a question for a different day: how to use this to talk about discontinuing treatment or continuing the treatment. At this point of time, the way I put it is, the deeper the response that people get measured—as the threshold 10-5 or 10-6—and the deeper it is—10-6 is better than 10-5—and the deeper the remissions are, the longer the response duration is.
In Emory, what we have done was to identify this a lot earlier, and we started using this ClonoSeq testing almost for the last 4 years. If you look back, we’ve sent ClonoSeq or the MRD testing for close to 750 patients. We have this longitudinal data that we're building, so that when there is a good time for us to make best use of this data, we'll be able to use it right away without having to wait for the testing and wait for that sustained amount of negativity.