Minimal residual disease following chemoimmunotherapy for patients with relapsed chronic lymphocytic leukemia

The goal of therapy in patients with chronic lymphocytic leukemia (CLL) is, whenever feasible, to induce sustained long-term complete remissions (CR). However, in most instances, patients in CR relapse after varying periods of progression-free survival (PFS). A number of studies have shown that patients, in whom detectable residual disease has been eradicated, have a longer duration of PFS than those in whom residual disease remains after treatment,1-4 especially when minimal residual disease (MRD) is measured using sensitive methods such as gated four-color flow cytometry (MRD Flow) or allele-specific oligonucleotide polymerase chain reaction (ASO-PCR).5 This article first reviews fludarabine-based chemotherapeutic regimens and immunotherapy with alemtuzumab. The rationale for the treatment of CLL with fludarabine plus alemtuzumab combination therapy is then discussed, followed by a review of the results obtained to date, particularly the capacity of this therapeutic approach to induce molecular remissions and long-lasting clinical responses.