By Sarah LaCorte
The results from the largest study to date analyzing chronic lymphocytic leukemia (CLL) treatment patterns among U.S. Veterans Health Administration (VHA) patients were presented at the ASCO 2020 Annual Meeting (Abstract e19339). The study described the pharmacoepidemiology of three novel agents—ibrutinib, idelalisib, and venetoclax—and traditional chemotherapies/chemoimmunotherapies (CT/CIT) in the VHA.
The first novel agent for use in CLL was approved in 2014; however, the extent of novel agent uptake in the VHA is largely unknown. There is a documented connection between CLL and U.S. veterans: The Health and Medicine Division (HMD) concluded in its report "Veterans and Agent Orange: Update 2008" released July 24, 2009, that there is sufficient evidence of an association between exposure to Agent Orange, herbicides, and CLL, including hairy cell leukemia and other chronic B-cell leukemias. As a result, VA expanded CLL to include all chronic B-cell leukemias as related to exposure to Agent Orange or other herbicides during military service. VA's final regulation recognizing this association took effect on October 30, 2010.
To investigate novel agent uptake in the VHA, the researchers conducted a retrospective study of 26,879 adults with CLL in the VHA from October 1, 2013, to May 31, 2018. Patients came from all 18 Veterans Integrated Service Networks, spanning all 50 states and U.S. territories. All were followed for at least 6 months.
The analyzed data was extracted from the VHA electronic health record. Descriptive statistics were used to summarize baseline characteristics, CLL treatments, next therapies, and secondary complications.
A total of 3,670 patients out of the 26,879 patients received at least one of 12 CLL therapies of interest. All of the patients had a median age of 69 years (47% were 65+ and 26% were 75+), with a median age-adjusted Charlson comorbidity score of 6. Also, 6 percent had a history of exposure to Agent Orange.
Ibrutinib accounted for 89 percent of the novel agent use. Ibrutinib use across all lines of therapy (LOTs) increased sevenfold over the study period. For the next LOT after Ibrutinib, venetoclax (42%) and idelalisib (30%) were the most common therapies.
Across all LOTs, traditional CT/CIT use declined steadily over the study period. However, in 2018, there were still 17 percent of patients receiving CT/CIT. Ibrutinib was the most common therapy for the next LOT in these patients (43-74%). Incidence of diffuse large B-cell lymphoma post-index was 2-6 times higher in patients on CT/CIT than those on ibrutinib. Other secondary complications were similar between ibrutinib and CT/CIT.
The authors concluded that based on this data, "there has been a major shift in the treatment of CLL, with fast adoption of novel agents in the VHA from 2013 to 2018. The impact of this shift on health care resource use and cost burden in the VHA will need to be examined."
Sarah LaCorte is a contributing writer.