Patients with chronic lymphocytic leukemia (CLL) who reduce their ibrutinib dose in the first-line setting do not compromise efficacy and can tolerate the medication well, according to a recent study.
Researchers from Canada and the United States examined treatment adherence and time to next treatment (TTNT) in 1,171 patients with CLL who were identified through electronic medical records in the Acentrus database from January 2016-April 2022. The researchers evaluated patients with and without a dose adjustment and a subgroup of patients with high cardiovascular risk at baseline.
Results of this study, presented at JADPRO Live 2023, the Annual APSHO Meeting, showed that all patients started treatment with the recommended ibrutinib dose of 420 mg a day. Of those patients, 88.6% (n=1,038) continued receiving that dose for at least 6 months. The median patient age was 70.2 years and 33.6% of patients were women. The median follow-up was 30.5 months. Nearly 20% (19.6%) of patients had a dose adjustment at any time post-index.
Within the first 6 months of treatment, 126 patients received a dose adjustment to receive a dose of less than 420 mg daily. However, the reasons for dose adjustments were not known. The patients receiving a dose adjustment had a mean age of 72.2 years and 42.9% were women. The median follow-up was 35.1 months.
In patients who lowered their dose, treatment adherence was higher based on proportion of days covered (PDC) and medication possession ratio (MPR). The mean PDC was 0.81 and MPR was 0.84. In the subgroup of patients with high cardiovascular risk at baseline who received a dose adjustment, the PDC was 0.78 and the MPR was 0.81. These findings were relative to patients without a dose adjustment, the authors said. The overall PDC for that group was 0.70 and the MPR was 0.73. The cardiovascular subgroup showed a PDC of 0.69 and an MPR of 0.72. The median TTNT was not reached in any of the groups.
Based on Kaplan-Meier estimates, the 12-month survival rates were 89.1% in patients with a dose adjustment and 92.7% in the subgroup of patients with high cardiovascular risk at baseline. Survival rates in patients with CLL who stayed on the initial ibrutinib dose were 92.5% and 92% in the subgroup of patients with high cardiovascular risk at baseline,
Regardless of baseline cardiovascular risk, patients who lowered their medication dose did not affect their TTNT relative to patients without a dose adjustment, according to the authors.
“These findings are consistent with other real-world studies and suggest that ibrutinib dose adjustment can be an effective treatment strategy that does not negatively affect efficacy while being well-tolerated outside of clinical trials,” the study authors said.
Rogers KA, Lu X, Emond B, et al. Real-world (RW) dosing patterns and outcomes among chronic lymphocytic leukemia (CLL) patients (pts) with or without an ibrutinib (IBR) dose adjustment (DA) in firstline (1L). Presented at JADPRO Live 2023, the Annual APSHO Meeting; November 9-12, 2023; Orlando, Florida.