Spotlight on chronic lymphocytic leukemia: A Pharma Matters report

A paradigm shift in the treatment of chronic lymphocytic leukemia (CLL) has taken place over the past decade, as therapies have progressed from providing palliative relief to inducing complete remission, eradicating minimal disease and improving survival. The development of Rituxan® (rituximab) and its use in immunochemotherapy regimens has transformed the treatment of CLL and is the current gold standard in physically fit individuals aged < 65 years. Despite this therapeutic development, Rituxan-based immunochemotherapy is limited in the two CLL groups that form the majority of CLL cases-the elderly and patients with comorbidities and high risk factors. Moreover, within 2 years of first- and second-line therapy, around 25% and 50% of patients relapse, respectively, and patients who experience remission for several years exhibit poor responses to subsequent therapies. Therefore, there still remains a significant unmet need in CLL. The rapid development of small-molecule agents targeting the B-cell receptor signaling pathway has been stimulated both by the association of this pathway with the initiation and progression of CLL as well as the high response rates and durable remissions reported in early-stage trials. Imbruvica (ibrutinib), an oral first-in-class Bruton's tyrosine kinase inhibitor, recently entered the market following accelerated approval in the relapsed/refractory setting, but long-term survival data are currently immature. New therapies face several significant challenges: to provide even greater response rates, particularly in the elderly and in patients with comorbidities and high risk factors, and to overcome resistance to current treatments. Currently, the only curative treatment for CLL, allogeneic hematopoietic stem cell transplantation, is not an option for the majority of CLL patients. The ultimate question is whether small-molecule therapeutics can achieve a cure for CLL. It is hoped that developments in identifying the cytogenetic and molecular changes associated with the prognosis and pathogenesis of CLL will enable the rapid development of next-generation targeted therapies.