New therapies in chronic lymphocytic leukemia

As outlined in previous chapters in this book, significant progress has been made in the predictive biomarkers for early disease progression and poor response to initial therapy in chronic lymphocytic leukemia (CLL). The applicability of many of these biomarkers to CLL relapsing from initial therapy is less well defined. More important to the outcome of patients relapsing after initial therapy is the duration of the initial remission and, potentially, the initial treatment utilized. Patients relapsing within six months of completing initial therapy have an extremely poor prognosis as compared with those with extended remissions following fludarabine-based therapy (1,2). Similarly, patients relapsing after combination chemoimmunotherapy have less therapeutic options available to them and, in general, have a lower response to subsequent therapy. In one study, complex karyotype also predicted poor outcome of therapy, but to date, there have been no large definitive studies demonstrating that del(17p13.1) or del(11q22.3) contributes to poor outcome in the relapse setting (3). This is likely reflective of the poor outcome of the majority of patients relapsing after initial treatment of symptomatic CLL.