Treatment Patterns in Patients with Chronic Lymphocytic Leukemia (CLL) Treated with B-Cell Receptor Inhibitors (BCRis) in Canada—a Medical Chart Review Study

Introduction

Several contemporary studies have demonstrated that patients with relapsed or refractory CLL who discontinue BCRi treatment have poor outcomes. In a large real-world study conducted in the US it was reported that intolerance was the most common reason for discontinuation of BCRi treatment. The objective of this study was to describe the characteristics, treatment patterns and rate of treatment changes among patients with CLL who are treated with a BCRi therapy in Canada.

Methods

The study was an observational, retrospective review of ONCO-CAPPS, a proprietary Canadian database of patient chart abstractions collected through regular survey of physician panels. Clinical data was collected for patients with CLL who had received treatment with BCRi therapy. Data extracted for review included patient demographics including comorbidities, BCRi treatment characteristics and type of BCRi treatment changes. Treatment changes were defined as dose reduction, treatment interruption and treatment discontinuation. Reasons for treatment discontinuation were also reported.

Results

Chart abstractions were conducted for 220 BCRi treated patients treated with CLL. More than half of the patients (59%) were male and the mean age was 71 years. Around 22% of the patients had a poor ECOG performance status score (≥2) and 27% had known 17p deletion. Majority (75%) of the patients had pre-existing comorbidities; of note half (53%) of all patients had at least one of: atrial fibrillation, hypertension, other cardiac comorbidity, impaired renal or respiratory function or a history of severe or recurrent infections. Most patients (88%) received BCRi therapy in the relapsed/refractory settings. Of the total patients, 22% (n=49) experienced a treatment change while on BCRi treatment. The proportion of patients reporting a treatment change increased with the duration on BCRi treatment which was calculated as the time the patient was observed in the chart. Stratified by duration of therapy, 4% (n=1/26) of the patients on BCRi treatment less than 3 months, 19% (n=16/86) of the patients on treatment for 3-6 months, 28% (n=13/46) of the patients on treatment for 6-12 months, and 31% (n=19/62) of the patients on treatment for more than 1 year experienced a treatment change. Of the total patients, 14% (n=30) discontinued treatment with BCRi and the median time to discontinuation was 6 months. The most common reason for discontinuation of treatment was disease progression (60%, n=18) followed by intolerance (17%, n=5).

Conclusion

This study describes treatment changes in real-world practice among CLL patients who initiated a BCRi therapy. Disease progression was the main reason for treatment discontinuation. Treatment changes occurred in many patients, particularly as the length of treatment increased. These real-world data in Canada demonstrate that assessment of treatment changes following prolonged treatment of BCRi greater than 6 months is beneficial to optimize therapy. There is also a clear unmet need for newer therapies specifically for CLL patients who have progressed on BCRi treatment or discontinued a BCRi treatment due to intolerance.