Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in the United States. There has been considerable progress in understanding the biology and treatment of CLL in last 20 years. The introduction of purine analogs (pentostatin, fludarabine, and cladribine) dramatically increased the response rates compared to alkylating agents. Combination chemoimmunotherapy has further improved the overall frequency of response to over 80% in treatment-naïve and over 60% in relapsed/ refractory disease, respectively.
Mahipal, Amit and Weiss, Mark, "The addition of rituximab to fludarabine and cyclophosphamide improves progression-free survival in patients with previously treated chronic lymphocytic leukemia." (2010). Department of Medical Oncology Faculty Papers. Paper 2.