Feasibility of Bruton's Tyrosine Kinase Inhibitor Discontinuation in Chronic Lymphocytic Leukemia: The Patient Perspective

Abstract

Background: Bruton's tyrosine kinase inhibitors (BTKi) have prolonged survival in chronic lymphocytic leukemia (CLL), however continuous administration increases toxicity. Little is known about clinical outcomes of patients who discontinue BTKi for reasons other than CLL progression. We aimed to report these outcomes.

Patients/methods: With the CLL Society, we solicited volunteers with CLL who self-reported BTKi discontinuation for reasons other than CLL progression to participate in a web-based survey.

Results: In 170 patients, BTKi was discontinued for toxicity, because CLL was in remission, or personal choice in 62%, 14% and 8%, respectively. When asked how they felt about stopping the BTKi, most were relieved that they may eliminate toxicity (45%), could focus less on CLL (11%), and would not have to pay for the medicine (7%), while 29% experienced anxiety. A statistically significant increase in perceived quality of life (QOL) was observed from prior- versus post-BTKi discontinuation. Of patients who reported that they experienced clinical CLL progression (n = 80), 46% reported that these events did not happen for ≥ 1 year after BTKi discontinuation. Those that were on a BTKi for ≥ 2 years before discontinuation had more time without CLL relapse.

Conclusions: These data provide a unique report of patient experiences. The data suggest that BTKi may be feasible and result in a period of treatment-free remission. The data also indicate that patients are generally relieved when they anticipate BTKi discontinuation and observe significant QOL improvements after BTKi discontinuation. As such, these data should prompt prospective study of time-limited BTKi therapy for CLL.

Keywords: Acalabrutinib; Drug holiday; Ibrutinib; Treatment discontinuation; Zanubrutinib.