December 9, 2023
By Catlin Nalley
A recent study, which took a closer look at the adoption of therapy options for chronic lymphocytic leukemia, identified a need for increased awareness of clinical treatment guidelines. These findings were recently presented during the 65th American Society of Hematology (ASH) Annual Meeting and Exposition, held December 9-12 in San Diego (Abstract 130).
“The treatment of CLL has been greatly advanced over the past decade, starting with ibrutinib, the first BTK inhibitor, then followed by the BCL2 inhibitor venetoclax,” noted study author Jing-Zhou Hou, MD, PhD, at the University of Pittsburgh Medical Center. “Newer BTK inhibitors were developed with acalabrutinib approved in November 2019 followed by zanubrutinib [in January 2023].”
Current guidelines recommend both BTK and BCL2 inhibitors for first-line treatment of chronic lymphocytic leukemia. Hou and colleagues “sought to understand how the standard of care has evolved among community oncologists since 2020 and assess which clinical and demographic factors impact treatment selection.”
The researchers used the Integra Connect PrecisionQ real-world de-identified database of over 3 million cancer patients across 500 sites of care to assess first-line treatment of 6,328 CLL patients between January 1, 2020, and June 30, 2023.
“For first-line CLL patients to be included, they must have had either ≥5 CLL/SLL diagnosed visits, or more CLL/SLL visits than non-CLL/SLL visits if the patient had less than five CLL/SLL diagnosed visits,” according to Hou.
In this analysis, the researchers measured first-line treatment use of first-generation BTK inhibitors, second-generation BTK inhibitors, BCL2 inhibitors, anti-CD20, and chemotherapy.
“We also assessed how use might be impacted by gender, age, race, ECOG, testing for del17p and TP53, positivity for TP53 or del17p, and pre-existing cardiac conditions,” Hou and team explained. “A subset of patients was evaluated through manual chart review to assess for TP53 and del17p mutations (n=1,029). Descriptive analyses were used and proportions were compared using a two-tailed, two-sample z-test.”
Among the different drug classes, the first-line use of BTK inhibitors was relatively consistent from 55.8 percent in 2020 to 56.3 percent in 2023, Hou reported during his presentation. “On the other hand, BCL2 inhibitor use increased from 14.6 percent in 2020 to 19.8 percent in 2023. Use of an anti-CD20 antibody or chemo-immunotherapy decreased from 29.5 percent in 2020 to 23.8 percent in 2023.” Data showed that the use of second-generation BTK inhibitors increased from 31 percent in 2020 to 80.7 percent of BTK inhibitor in 2023.
When looking at different age groups, the researchers found that 48.9 percent of patients 60 years and younger (n=630) received a BTK inhibitor compared to 59.6 percent of patients aged 80 and older (n=2,094). The researchers reported that first-line BTK inhibitor use was similar between male and female patients; however, the use of BCL2 inhibitors was higher among males when compared to their female counterparts. Among patients treated with a BTK inhibitor since 2020, Hou and colleagues found no significant difference in first-line treatment based on race when comparing Black/African American and White patients.
“The combined use of BCL2 inhibitors and the second-generation BTK inhibitors in the first-line increased from 32.5 percent in 2020 to 65.2 percent in 2023. Second-generation BTK inhibitor use among BTK inhibitors has increased from 31.2 percent to 80.7 percent in 2023,” Hou noted. “However, in 2023, more than 33 percent of patients did not receive either BTK or BCL2 inhibitors, with nearly 9 percent continuing to receive chemo-immunotherapy,” he added. Hou said that BTK or BCL2 inhibitors are used less often in female patients, as well as patients 80 years or older, those with ECOG ≥2, and patients who were not tested for del17p and TP53 mutation.
“This analysis suggests a need to increase the awareness of the clinical guidelines and for treatment for chronic lymphocytic leukemia and to further understand why such differences exists in treatment selection,” he concluded.
Catlin Nalley is a contributing writer.