Ibrutinib-Treated Older Patients with CLL Have Threefold Higher Risk of AF

In older adult Medicare beneficiaries with CLL, treatment with ibrutinib was associated with a nearly threefold increased risk of atrial fibrillation (AF), according to study findings presented at the 62nd American Society of Hematology Annual Meeting & Exposition.

The study was presented by Akiva Diamond, MD, of the Baylor St. Luke’s Medical Center in Houston. Dr. Diamond explained that he and his colleagues conducted an analysis of the SEER-Medicare database to identify Medicare beneficiaries aged 66 years and older with CLL. Medicare Part B and D data were used to identify which treatments were used for these patients. The primary outcomes of the analysis were AF and stroke.

Approximately 6% (n=299) of the 4,958 patients with CLL in the SEER-Medicare database were treated with ibrutinib. The median age in the ibrutinib-treated population was 75 years, and the majority of these patients were white (90.3%).

In the 2,169 patients with CLL who were never treated, the stroke incidence was 11.9% following CLL diagnosis (incidence rate, 47.7/1,000 person-years), whereas the incidence of AF was 15.2% (60.6/1,000 person-years).

The incidence rates of stroke and AF among patients treated with an agent other than ibrutinib were 54.69/1,000 and 67.2/1,000 person-years, respectively. In contrast, the incidence rate of AF was 221.8/1,000 person-years, and the incidence rate of stroke was 72.9/1,000 person-years among patients treated with ibrutinib.

In an analysis that adjusted for potential confounders, the risk of AF was threefold higher for patients treated with ibrutinib compared with patients who received a different therapy (hazard ratio [HR], 3.0; 95% confidence interval [CI], 2.1-4.4). No similar association was found between treatment with ibrutinib compared with another treatment in terms of stroke risk (HR, 1.1; 95% CI, 0.48-2.3).

In their abstract, the researchers wrote that future analyses should examine the risk of other complications in patients with versus without CLL. They added that further studies should look at the correlation between complications and the treatment of widespread Bruton’s tyrosine kinase inhibitor use, among other targeted treatments for CLL.