OBJECTIVES: Pirtobrutinib is a non-covalent (reversible) BTK inhibitor (BTKi) with FDA approval for patients with MCL after at least two lines of systemic therapy, including a BTKi, and for patients with CLL/SLL who have received at least two prior lines of therapy, including a BTKi and a BCL-2i. Accelerated approval was based on the single-arm BRUIN trial (NCT03740529, LOXO-BTK-18001). A budget impact model was developed to estimate the impact of introducing pirtobrutinib as a treatment option for patients with MCL or CLL/SLL in the US.

METHODS: Disease incidence was estimated using Surveillance, Epidemiology, and End Results data; proportions of patients who received therapy after discontinuation of BTKi or BTKi and BCL2i, respectively, were estimated from the nationwide Flatiron Health electronic health record-derived de-identified database. Costs were estimated from published sources for drugs and their administration, healthcare monitoring, and grade 3/4 adverse events. The BRUIN trial and Flatiron Health database provided estimates of treatment duration. Total and per-member-per-month (PMPM) costs were estimated over a 5-year period per million members. Robustness of findings was evaluated with one-way sensitivity analyses (OWSA).

RESULTS: Annually, 0.3 and 4.3 per million members would receive pirtobrutinib in MCL and CLL/SLL, respectively, assuming 50% market share. Total combined MCL/CLL/SLL incremental budget impact for commercial and Medicare payers ranged from $5,970 and $121,663, respectively, in year-1 to $18,894 and $366,602, respectively, in year-5. Combined incremental PMPM costs for commercial and Medicare ranged from $0.001 and $0.011 (year-1) to $0.002 and $0.032 (year-5), respectively. OWSA showed that pirtobrutinib’s treatment duration and acquisition costs had the greatest impact on results.

CONCLUSIONS: This model demonstrated minimal budget impact of pirtobrutinib for patients with MCL or CLL/SLL, largely due to small patient populations eligible for treatment. This model used published acquisition costs, which may not reflect actual price paid by all US payers.