OBJECTIVES: Pirtobrutinib is a reversible non-covalent BTKi agent that is currently being evaluated in patients with a variety of B-cell malignancies, including Mantle Cell Lymphoma (MCL) (NCT03740529, BRUIN, LOXO-BTK-18001 ). MCL is a rare condition diagnosed in less than 3,341 people per year in the United States (U.S.). This study was designed to estimate the annual population of patients with MCL who may be eligible for treatment with pirtobrutinib in commercial and Medicare health plans in the U.S.
METHODS: Surveillance, Epidemiology, and End Results (SEER) data were used to estimate the incidence of MCL; real-world data were used to estimate the proportion of eligible patients who received cBTKi and >2 lines of systemic therapy. Treatment market share was estimated from real-world data and was used to develop a framework for a budget impact model for pirtobrutinib.
RESULTS: The annual incidence of MCL is 0.5 and 4.5 per 100,000 in patients aged 20-64years and ~65years for U.S. commercial and Medicare health plans, respectively. Approximately 21.4% of patients with MCL received cBTKi therapy, and 59% received >2 lines of systemic therapy. The treatments from which pirtobrutinib may pull market share in this setting were heterogeneous and include bendamustine + rituximab; lenalidomide +/- rituximab; rituximab monotherapy, venetoclax, additional cBTKi treatment; Chimeric Antigen Receptor T-cell therapy (CAR-T), and chemotherapy. Based on these findings, an estimated 0.4 and 5.7 patients per million would receive pirtobrutinib in the commercial and Medicare populations, respectively, if it claims 100% market share in this setting. The proportion of patients who will receive pirtobrutinib would range from 0.2 to 2.9 per million members if it achieves 50% of the total postcBTKi market share.
CONCLUSIONS: These findings provide a specific quantification of the anticipated number of patients potentially eligible for treatment with pirtobrutinib and show very low patient numbers for U.S. payers.
