Cost-Effectiveness Analysis of Tisagenlecleucel for the Treatment of Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma in the United States
Clinical Therapeutics, 2021
Purpose
To assess the cost-effectiveness and cost-effective price of tisagenlecleucel, a novel, effective chimeric antigen receptor T-cell therapy, versus salvage chemotherapy (SC) for the treatment of relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL) using a willingness-to-pay (WTP) threshold of $150,000 per quality-adjusted life year (QALY) gained from a US third-party payer's perspective.
Methods
A three-state (progression-free survival, progressive disease, and death), responder-based partitioned survival model with a lifetime horizon and 3% annual discount rate was developed. Overall survival (OS) and progression-free survival of tisagenlecleucel were estimated separately for patients with and without an overall response (OR), using data from JULIET ( Study of Efficacy and Safety of CTL019 in Adult DLBCL Patients). OS of SC was informed by SCHOLAR-1 (Retrospective Non-Hodgkin Lymphoma Research). Mixture cure models were used to inform the survival of tisagenlecleucel responders, supported by JULIET. The median OS was 11.1 months in all tisagenlecleucel-treated patients but not reached for responders; no progression or death occurred among responders since month 22 of treatment. For tisagenlecleucel nonresponders and SC, survival was based on standard parametric models until month 60and the survival of DLBCL long-term survivors thereafter. The model prediction validated well against the observed trial data. Costs and utilities were from the literature; utilities depended on health states and were used to estimate QALYs. Total costs, QALYs, and incremental cost per QALY gained were estimated. A cost-effective price range was estimated for all tisagenlecleucel-treated patients, OR responders, and complete response (CR) responders. Deterministic sensitivity and scenario analyses and a probabilistic sensitivity analysis were performed. All costs were reported in or inflated to 2020 US dollars.
Findings
Tisagenlecleucel was associated with 3.35 QALYs gained versus SC.,The estimated incremental costs per QALY gained versus SC were $78,652 using the wholesale acquisition cost of $373,000 for tisagenlecleucel. The estimated cost-effective price of tisagenlecleucel in all treated patients was $612,270 at the WTP threshold of $150,000. Tisagenlecleucel OR and CR responders had an increase of 7.82 and 9.34 QALYs versus SC, with cost-effective prices estimated at $1,281,456 and $1,551,974, respectively. Sensitivity analysis results supported the base case findings.
Implications
Tisagenlecleucel is a cost-effective treatment versus SC for r/r DLBCL from the perspective of a US third-party payer. The estimated cost-effective prices ranged from $612,270 (all tisagenlecleucel-treated patients) to up to $1.5 million (patients achieving CR). Limitations include the use of single-arm trials due to data availability.