Real World Treatment Patterns in Chronic Lymphocytic Leukemia Patients in the United States - Rituximab, the Most Commonly Used Agent

CLL is an indolent incurable lymphoma with a widely variable disease course. Its treatment is therefore quite heterogeneous. The goal of this project was to evaluate the real-world use of individual agents or combination regimens across all lines of therapy in CLL during the years 2010-2013 in order to understand the current treatment paradigm of CLL. Treatment records for 110,000 cancer patients and over 6.7 million drug administrations were evaluated between August 2010 and July 2013 at US cancer care facilities participating in a nationwide, commercially available chemotherapy order entry system called IntelliDose®. IntelliDose® captures patient demographics, stage, and details of chemotherapy treatment. The composition of the 820 oncologists who use IntelliDose® is much like the overall population of oncologists in the US, including 54% in private practice and 41% community hematologist/oncologists. The CLL patients sampled by IntelliDose® were projected to a national level for the interpretation of the results. The average monthly number of CLL patients undergoing any line of treatment was 7,736 (SD= 565). Of the 3,380 patients receiving first line therapy, the majority of patients (n=810; 24%) were receiving Bendamustine-Rituximab (BR), followed by Fludarabine- Cyclophosphamide -Rituximab (FCR) (n=716; 21%).For relapsed CLL, BR was also the most common regimen (18-33% of monthly use), followed by R monotherapy (7- 16% of monthly use). Across all lines of therapy, BR is the most common regimen used (14-32% monthly use) followed by R alone as the second most common regimen (18-25% of monthly use). Rituximab is the most frequently used agent either as a single agent or in combination, in all lines of CLL treatment in the US. Single agent Rituximab is commonly used in CLL therapy in 2nd line and above, despite low reported response rates in the literature.