Cost Effectiveness Analysis of Tisagenlecleucel for the Treatment of Adult Patients with Relapsed or Refractory Diffuse Large B Cell Lymphoma in Japan

There are limited treatment options and substantial unmet needs for adult patients with relapsed or refractory diffuse large B cell lymphoma (r/r DLBCL) in Japan. In 2019, tisagenlecleucel, a CD19-directed chimeric antigen receptor T cell therapy, was approved for r/r DLBCL in Japan. The efficacy and safety of tisagenlecleucel were demonstrated in the pivotal phase II single-arm JULIET trial. The objective of the current study was to assess the cost-effectiveness of tisagenlecleucel treatment strategy versus current standard of care (salvage chemotherapy treatment strategy) for the treatment of patients with r/r DLBCL in Japan. A three-state partitioned survival model was constructed from a Japanese public healthcare payer's perspective, with the following three health states: progression-free survival, progressive/relapsed disease, and death. Because the tisagenlecleucel arm included patients who did or did not receive the infusion, a decision-tree structure was used to partition patients based on their infusion status. Treatment efficacy and costs were based on tisagenlecleucel-infused patients for those who received the infusion; for non-infused patients, they were based on standard salvage chemotherapy. The efficacy inputs for tisagenlecleucel-infused patients and salvage chemotherapy were based on observed data in the JULIET trial and the international SCHOLAR-1 meta-analysis, respectively, before year 3. Afterward, all patients were assumed to have no further progression and to incur the mortality risk of long-term DLBCL survivors. The base case analysis explored a lifetime horizon (44 years), with costs and effectiveness discounted 2.0% annually, and it used a monthly model cycle. Direct costs were considered in the base case, composed of pretreatment costs, treatment costs, adverse events management costs, follow-up costs before progression, subsequent SCT costs, post-progression costs, and terminal care costs. Total incremental costs, life years (LYs), and quality-adjusted life years (QALYs) were compared for tisagenlecleucel versus salvage chemotherapy. The incremental cost-effectiveness ratio (ICER) was estimated as the costs per QALY gained, and a threshold of ¥7.5 million was used to assess whether tisagenlecleucel is cost effective. Deterministic and probabilistic sensitivity analyses were performed. The total LYs (discounted) for tisagenlecleucel and salvage chemotherapy were 7.24 and 4.35 years, respectively; the corresponding QALYs were 5.42 and 2.57 years, respectively. The discounted incremental LYs and QALYs comparing tisagenlecleucel to salvage chemotherapy were estimated as 2.89 and 2.85 years, respectively. Over a lifetime horizon, the model estimated that tisagenlecleucel had a total incremental cost of ¥15,590,335 (discounted) versus salvage chemotherapy. Tisagenlecleucel was associated with an ICER of ¥5,476,496 per QALY gained compared to salvage chemotherapy. Extensive sensitivity analyses supported the base-case findings. Tisagenlecleucel is a cost-effective treatment strategy for r/r DLBCL compared to salvage chemotherapy treatment strategy from a Japanese public healthcare payer's perspective.