Part 2:
Redefining the CR criteria in MM:
cellular dissemination

Maria-Victoria Mateos, MD, PhD
University Hospital of Salamanca, Spain

TRANSCRIPT
And in order to evaluate in-depth the complete response category, we can focus on the cellular dissemination, cellular production and cellular clonality. If we start by cellular dissemination, Elena Zamagni addressed this morning this topic, so I will go fast through this topic, because PET/CT is established as the assessment to evaluate the extramedullary disease in multiple myeloma. And you can see here like the PET/CT has prognostic value even at diagnosis in newly diagnosed myeloma patients, not only the SUVA value, the number of focal lesions as well as the presence of extramedullary disease.

But also the PET/CT has a prognostic value after induction, and before autologous stem cell transplantation and in different studies where PET/CT is negative, the outcome is better. But also after autologous stem cell transplantation and she said in her presentation that PET/CT should be done at least after autologous stem cell transplantation when PET/CT becomes negative, the outcome is much more relevant, is much more longer and in fact in a multivariate analysis the PET/CT negativity remained as independent prognostic values, predicting both progression-free survival and overall survival.

And although the information in the non-transplant eligible for newly diagnosed myeloma patients is reduced, also PET/CT can have a prognostic value and the use of this new imaging assessments in order to evaluate the minimal residual disease outside of the bone marrow should not be restricted to the bone marrow, but also outside of the bone marrow through the use of PET/CT.

And this is the last study that she presented at last ASH using a couple of different studies, one of them conducted by the French group, the other one conducted by the Italian myeloma group in order to try to standardize the PET/CT criteria in order to evaluate the response in the upfront setting. And she discussed this morning how the Deauville score is valued also for myeloma and was discussing about the Deauville score as an important factor predicting progression-free survival and overall survival in an independent way in both studies.

So the first message that I would like to give you is that the new response criteria published by IMWG in 2016 incorporated the imaging MRD negative, considering that a patient would be in MRD negative by imaging when the PET/CT is negative after autologous stem cell transplantation I would say that at least at the moment in which the patient is in biochemical complete response, at that moment I think that the imaging should be evaluated, as well as the bone marrow and at that time we can consider that the patient is in imaging MRD negative.