Acalabrutinib was approved by the FDA in November 2019 for the treatment of adults with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma, following its approval in October 2017 for patients with mantle-cell lymphoma (MCL) who had progressed on at least 1 prior therapy.
At the 2019 meeting of the American Society of Hematology, researchers led by Kellie Ryan, MPH, from AstraZeneca, looked at the real-world characteristics of patients with CLL and MCL who are being treated with acalabrutinib in the United States. In the study, researchers evaluated adult patients who were prescribed acalabrutinib between November 1, 2017, and April 30, 2019.
A total of 264 MCL and 204 CLL patients treated with acalabrutinib were identified and studied. Typical of patients with CLL or MCL, the median age of those included in the study was 71.5 years, and the majority of patients were male. About half of the patients had private health insurance.
About two-thirds (64.7%) of the CLL patients and one-third (37.9%) of the MCL patients had received the drug ibrutinib before they began taking acalabrutinib. The reasons for discontinuing ibrutinib were not explored, but none of the patients took both drugs at the same time.
Many of the patients studied had other health conditions (known as comorbid conditions) in addition to CLL or MCL. The most common comorbid conditions were high blood pressure (67.8% MCL/67.7% CLL), other blood cancers (48.9% MCL/52.0% CLL), and infection (28.0% MCL/31.4% CLL). Comorbid conditions that affected 20% or more of the CLL group included arrhythmia, fatigue/lack of energy, atrial fibrillation, anemia, and thrombocytopenia (a deficiency of platelets in the blood). Interestingly, more than 60% of patients in each patient group were considered to be at high risk of atrial fibrillation, a relatively common condition in older adults.
The researchers found that more patients who had taken ibrutinib previously were at high risk for atrial fibrillation (70.5% in the CLL cohort; 64.0% in the MCL cohort) when they started acalabrutinib than patients without prior ibrutinib use (52.8% in the CLL cohort; 58.5% in the MCL cohort). About three-fourths (72.0%) of prior ibrutinib users had a history of high blood pressure, with a similar percentage in the CLL and MCL groups. Among those with prior ibrutinib use, 25.5% of the CLL patients and 19.0% of the MCL patients had a history of arrhythmia. Fatigue/lack of energy was also more common in prior ibrutinib users in both the CLL and MCL cohorts compared with those patients without prior ibrutinib use.
Although the study found some interesting differences in patients with prior ibrutinib use versus those who had not used ibrutinib, it was not designed to uncover the reasons for these differences. However, future studies may be developed to help answer these questions to help guide physicians and patients in making the most appropriate treatment choices for those with CLL and small lymphocytic lymphoma.