Cost-effectiveness analysis of teclistamab plus daratumumab in relapsed or refractory multiple myeloma.

11038 Background: Relapsed or refractory multiple myeloma (RRMM) remains a significant therapeutic and economic challenge as patients progress through successive lines of therapy. Teclistamab, a CD3×B-cell maturation antigen (BCMA) bispecific antibody, has demonstrated deep and durable responses in heavily pretreated patients in the phase 1–2 MajesTEC-1 trial. Daratumumab, an anti-CD38 monoclonal antibody, is a cornerstone of modern myeloma treatment. The phase 3 MajesTEC-3 trial evaluated teclistamab plus daratumumab versus daratumumab-based regimens, including daratumumab with pomalidomide and dexamethasone (DPd) or with bortezomib and dexamethasone (DVd) in patients with RRMM. While teclistamab-based combinations have demonstrated strong clinical efficacy, their economic value relative to standard daratumumab-based regimens remains uncertain. Methods: We extracted event-free survival (EFS) and overall survival (OS) data from published Kaplan–Meier curves and reconstructed individual patient data using a validated algorithm (IPDfromKM). A Markov model was developed to compare lifetime costs and health outcomes between treatment strategies. Model inputs were obtained from the Centers for Medicare & Medicaid Services, the Medicare Physician Fee Schedule, and published literature. Health state utilities, adverse event rates, treatment discontinuation probabilities, and toxicity costs were derived from the MajesTEC-3 trial and peer-reviewed sources. Analyses were conducted from a U.S. third-party payer perspective, with costs reported in 2025 U.S. dollars. Cost-effectiveness was assessed using incremental cost-effectiveness ratios (ICERs) with a $150,000/QALY willingness-to-pay (WTP) threshold, and robustness was examined through one-way and probabilistic sensitivity analyses. Results: Gompertz and lognormal distributions were selected based on Akaike Information Criterion to extrapolate EFS and OS for the teclistamab–daratumumab and DPd/DVd arms, respectively. Using a Markov model, teclistamab plus daratumumab yielded an incremental gain of 1.16 QALYs compared with DPd/DVd, at an additional cost of $95,376, resulting in an ICER of $82,074 per QALY, well below the WTP threshold. Probabilistic sensitivity analysis showed that 88.9% of simulations favored teclistamab plus daratumumab at the $150,000/QALY threshold. Treatment discontinuation rates and the cost of daratumumab in the DVd regimen were the primary drivers of ICER estimates. Conclusions: From a U.S. payer perspective, teclistamab plus daratumumab is cost-effective compared with DPd or DVd in patients with RRMM, supporting its broader adoption in clinical settings. Base-case model. Strategy Cost, USD Incremental cost, USD Effectiveness, QALY Incremental effectiveness, QALY ICER, USD/QALY Teclistamab-Daratumumab 445,405 95,376 16.72 1.16 82,074 DPd or DVd 350,029 15.55