Cost per responder for teclistamab and elranatamab in relapsed or refractory multiple myeloma in the United States.

Teclistamab and elranatamab are bispecific antibodies recently approved for the treatment of triple class-exposed relapsed/refractory multiple myeloma (RRMM). This study assessed the relative efficacy and economic value of teclistamab and elranatamab through a matching-adjusted indirect comparison (MAIC) and cost per responder analysis using data from the MajesTEC-1 (NCT03145181/NCT04557098) and MagnetisMM-3 (NCT04649359) trials. The MAIC compared overall response rate (ORR) between the therapies after weighting individual patient data from MajesTEC-1 to match key baseline characteristics in MagnetisMM-3. Matched covariates included age, refractory status, prior lines of therapy, extramedullary disease, performance status, disease stage, and cytogenetic risk profile. Cost per responder was calculated based on estimated per-patient drug acquisition and administration cost (2024 United States dollars) over 6 months divided by ORR. One-way and probabilistic sensitivity analyses were conducted to characterize uncertainty. The ORRs were 63.0% for teclistamab before matching (N = 165), 61.4% for teclistamab after matching (effective sample size = 92), and 61.0% for elranatamab (N = 123) (odds ratio after matching: 1.02; 95% confidence interval [CI]: 0.59, 1.77). Per-patient costs were estimated to be $231,435 for teclistamab and $285,201 for elranatamab (difference: -$53,766; 95% confidence interval [CI]: -$59,094, -$48,311), yielding costs per responder of $376,930 and $467,730, respectively (difference: --$90,800; 95% CI: -$183,680, $8,148). Because MajesTEC-1 and MagnetisMM-3 are single-arm trials, the MAIC was unanchored and therefore susceptible to confounding from any unadjusted effect modifiers or prognostic variables. Teclistamab was associated with significantly lower treatment costs and numerically lower cost per responder than elranatamab in triple class-exposed RRMM.