The role of minimal residual disease measurements in the therapy for CLL: is it ready for prime time?

With the advent of multiple highly effective treatment options, minimal residual disease (MRD) measurements gained interest as a prognostic marker in chronic lymphocytic leukemia. This article provides a model explaining the clinical significance of MRD in different clinical situations and reviews available data to support that model. Factors with a possible impact on the clinical significance of MRD are discussed: technique for MRD quantification, treatment regimen, clinical response, time-point for sampling, and the additional impact of molecular risk features. Also described are data supporting the use of MRD assessments as a surrogate end-point in randomized clinical trials.