Ibrutinib dose reductions and discontinuations due to adverse events (AEs) are higher in routine clinical practice than in clinical trials, according to results from a study presented at the virtual 62nd American Society of Hematology (ASH) Annual Meeting and Exposition.
This multicenter, retrospective chart review study was presented by Jing-Zhou Hou, MD, PhD, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. The aim of the study was to describe ibrutinib dose reductions and discontinuations in patients with CLL.
“Real-world studies of ibrutinib in CLL patients have shown higher rates of discontinuations due to adverse events (AEs; 14-23%) compared with data from the early clinical trials of ibrutinib (4-9%),” wrote Dr Hou and colleagues.
“Similarly, dose reduction rates due to AEs in the real-world studies were 22-28%, vs 9% in the ibrutinib package insert,” they continued, noting that most of these real-world studies were focused on the academic setting rather than registry data.
Patient data from 2 community networks and 1 academic practice were used. Each community network supplied data for 50 randomly selected patients receiving ibrutinib. All patients meeting inclusion criteria from the academic site were included.
Patients were included if they had confirmed diagnosis of CLL, initiation of ibrutinib between March 2014 and June 2019, and ≥18 years of age at the initiation of therapy.
A total of 180 patients with CLL were included in the study, 56% of whom were treated in the community setting. Of the 180 patients included, 56 (31%) received ibrutinib in the first-line setting and 124 (69%) received ibrutinib in a relapsed or refractory line.
Patients treated in the first-line setting had a median follow-up of 26 months. At least 1 dose reduction was reported in 14 (25%) patients, mostly due to AEs (79%). Median time to the first dose reduction was 9.9 months.
Additionally, treatment discontinuations were reported in 20% of patients more commonly due to AEs (75%) than disease progression (9%). Median duration of treatment among those who discontinued ibrutinib was 15 months; 6 months for discontinuations due to AEs versus 28.9 months for disease progression.
Patients treated in relapsed/refractory settings had a median follow-up of 28.5 months. At least 1 dose reduction was reported in 34 (27.5%) patients, again mostly due to AEs (88%). Median time to first dose reduction was 3.1 months.
Additionally, treatment discontinuation was reported in 40% of patients, 58% of which were due to AEs compared to 18% due to disease progression. Median duration of treatment among relapsed/refractory patients was 9 months; 6 months for discontinuations due to AEs and 30.2 months for disease progression.
“Dose reductions and discontinuations were frequent in CLL patients receiving ibrutinib in routine clinical practice. Compared with ibrutinib clinical trial data at a similar follow-up time, AEs were the most common reasons leading to discontinuation of ibrutinib rather than disease progression,” concluded Dr Hou and colleagues.
“The rates of dose reduction and discontinuations due to AEs in our study were higher than in clinical trials and were consistent with other real-world studies, indicating similar patterns in both community and academic settings,” they added.—Janelle Bradley
Hou JZ, Ryan K, Du S, et al. Dose Reductions and Discontinuations with Chronic Lymphocytic Leukemia (CLL) Patients Receiving Ibrutinib in Community and Academic Settings. Presented at: the virtual 62nd ASH Annual Meeting and Exposition; December 5-8, 2020. Abstract 1660.
