OBJECTIVES: Evaluate treatment outcomes among patients with mantle cell lymphoma (MCL) treated with the Bruton’s tyrosine kinase inhibitors (BTKis) ibrutinib or acalabrutinib in second- or later-line therapy (2L+).

METHODS: Adults with MCL who initiated single-agent ibrutinib or acalabrutinib in 2L+ (index date) on or after 10/31/2017 (date of acalabrutinib approval for MCL) were analyzed using insurance claims from Optum’s de-identified Clinformatics^® Data Mart Database (04/30/2017-12/31/2021). Treatment persistence (defined as not having a gap for >90 days in treatment) was evaluated among patients with sufficient potential follow-up (index date at least 15 months before end of data, with at least 60 days continuous enrollment post-index) to observe discontinuation; comparisons between cohorts were conducted using a multivariate Cox proportional hazards model. All models were adjusted for baseline characteristics observed during the 6-month period pre-index.

RESULTS: A total of 50 patients treated with ibrutinib (mean age: 76.3 years; 58.0% male) and 48 patients treated with acalabrutinib (mean age: 76.4 years; 64.6% male) were included. Among patients with sufficient potential follow-up post-index, 62.8% and 75.0% of patients discontinued ibrutinib and acalabrutinib, respectively, with a median time to discontinuation of 8.9 and 5.7 months, respectively (adjusted hazard ratio=0.79; P=0.496). Among patients without use of a BTKi in a preceding line of therapy with sufficient potential follow-up, median time to discontinuation was 8.9 and 6.9 months for ibrutinib and acalabrutinib cohorts, respectively (adjusted hazard ratio=0.81; P=0.610). Among patients receiving chemoimmunotherapy in first-line (1L) and with sufficient potential follow-up, median time to discontinuation was 9.3 and 4.4 months for ibrutinib and acalabrutinib, respectively (adjusted hazard ratio=0.47; P=0.085).

CONCLUSIONS: Treatment persistence was similar in patients with MCL treated with ibrutinib or acalabrutinib in 2L+, with slightly longer median time to discontinuation observed among patients treated with ibrutinib.