Number needed to treat and associated cost analysis of zanubrutinib vs ibrutinib in chronic lymphocytic leukemia.

Background: Zanubrutinib, a Bruton tyrosine kinase inhibitor, is an approved treatment for chronic lymphocytic leukemia (CLL).

Objective: To compare zanubrutinib vs ibrutinib for relapsed refractory (R/R) CLL by calculating the number needed to treat (NNT) to avoid 1 progression or death and the associated cost impact.

Methods: An NNT analysis was conducted to estimate the number of patients with R/R CLL that need to be treated to prevent 1 progression or death. Clinical efficacy data were derived from the ALPINE trial, with 24-month progression-free survival (PFS) data from the final analysis of the ALPINE trials used for the base-case analysis. An economic analysis was conducted from a US payer perspective to assess the cost impact associated with NNT, incorporating costs of direct treatment, adverse event management, medical resources utilization, and subsequent treatment. It quantified the PFS-based NNT, the incremental cost per treated patient, and incremental cost per additional patient experiencing progression or death. Deterministic sensitivity analyses were performed to evaluate parameter uncertainties and identify key drivers. Scenario analyses explored different PFS estimates.

Results: In the base-case analysis, treating 8 patients with zanubrutinib instead of ibrutinib prevented 1 progression or death. The total costs per patient treated with zanubrutinib and ibrutinib were $399,928 and $447,059, respectively, with cost savings of $47,132 per zanubrutinib-treated patient. Drug costs and PFS are the major impact factors on the incremental cost per patient. In the scenario analyses, the NNT ranged from 8 to 12, with cost savings of $46,105-$52,860 per zanubrutinib-treated patient. In a hypothetical 100-patient clinical practice, zanubrutinib could prevent approximately 13 progression or death events.

Conclusions: Zanubrutinib may offer more favorable clinical outcomes with cost savings compared with ibrutinib for R/R CLL treatment from a US payer perspective. Additionally, cost savings could be realized from the Enhancing Oncology Care model, a value-based payment structure that incentivizes providers to deliver high-quality care while reducing overall health care spending.