Purpose: The MAIA trial found that addition of daratumumab to lenalidomide and dexamethasone (DRd) significantly prolonged progression-free survival in transplant-ineligible patients with newly diagnosed multiple myeloma, compared with lenalidomide and dexamethasone alone (Rd). However, daratumumab is a costly treatment and is administered indefinitely until disease progression. Therefore, it is unclear whether it is cost-effective to use daratumumab in the first-line setting compared with reserving its use until later lines of therapy.
Methods: We created a Markov model to compare healthcare costs and clinical outcomes of transplant-ineligible patients treated with daratumumab in the first-line setting compared with a strategy of reserving daratumumab until the second-line. We estimated transition probabilities from randomized trials using parametric survival modeling. Lifetime direct healthcare costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for first-line daratumumab versus second-line daratumumab from a US payer perspective.
Results: First-line daratumumab was associated with an improvement of 0.52 QALYs and 0.66 discounted life-years compared with second-line daratumumab. While both treatment strategies were associated with considerable lifetime expenditures ($1,434,937 v $1,112,101 in US dollars), an incremental cost of $322,836 for first-line daratumumab led to an ICER of $618,018 per QALY. The cost of daratumumab would need to be decreased by 67% for first-line daratumumab to be cost-effective at a willingness-to-pay threshold of $150,000 per QALY.
Conclusion: Using daratumumab in the first-line setting for transplant-ineligible patients may not be cost-effective under current pricing. Delaying daratumumab until subsequent lines of therapy may be a reasonable strategy to limit healthcare costs without significantly compromising clinical outcomes. Mature overall survival data are necessary to more fully evaluate cost-effectiveness in this setting.