Better therapy requires better response evaluation: Paving the way for minimal residual disease testing for every myeloma patient.

In 2015, there is a large body of evidence demonstrating that minimal residual disease (MRD) negativity after therapy is a powerful predictor of progression-free survival and overall survival in multiple myeloma. On the basis of available data, we believe MRD provides a meaningful endpoint for regulatory purposes, academic studies, and a valuable prognostic evaluation of individual patients in the clinical setting. Similar to what has been shown in acute and chronic lymphocytic leukemia, based on emerging data, the prognostic impact of MRD in multiple myeloma appears to be independent of induction therapy received. This fact raises fundamental questions regarding best possible treatment strategies (e.g., fixed number of cycles versus response adapted number of cycles) as well as optimal treatment modalities (e.g., newer effective but less intense combination therapies versus high dose melphalan followed by autologous stem cell transplantation), in particular for patients newly diagnosed with multiple myeloma.