BACKGROUND: In recent years, the FDA has approved several 3-agent (i.e., triplet) combinations for previously treated multiple myeloma (MM), and the National Comprehensive Cancer Network (NCCN) now recommends triplet regimens over doublets. Little is known about the real-world cost of triplet combinations because of the limited time that they have been on the market since FDA approval. Furthermore, traditional cost analyses developed to support market entrance rely on utilization assumptions that are difficult to validate when numerous comparators simultaneously enter the market. OBJECTIVE: To perform a 1-year cost analysis of novel triplets used for the treatment of patients with previously treated MM controlling for differences in utilization. METHODS: FDA-approved, NCCN-recommended (preferred and category 1 for previously treated MM) treatments included in the analysis were daratumumab plus lenalidomide plus dexamethasone (DARA/LEN/DEX), daratumumab plus bortezomib plus dexamethasone (DARA/BOR/DEX), elotuzumab plus lenalidomide plus dexamethasone (ELO/LEN/DEX), carfilzomib plus lenalidomide plus dexamethasone (CAR/LEN/DEX), and ixazomib plus lenalidomide plus dexamethasone (IXA/LEN/DEX). To control for market uptake, the model was designed to estimate the cost of treating an average patient over a 1-year time horizon. Drug administration and dosing, required comedications, postprogression therapy, monitoring requirements, and adverse event (AE) rates were based on FDA prescribing information or clinical trials. AEs >= grade 3 that occurred in >= 5% of patients were included. RED BOOK wholesale acquisition costs were used for drug acquisition costs. Costs of drug administration, AE management, and patient monitoring were based on the 2018 Center for Medicare & Medicaid Services payment rates or from published literature (inflated to 2018 U.S. dollars). The treatment duration for each regimen was estimated from modeled progression-free survival data; the 12-month progression-free survival rate was assumed to be equivalent to the probability that an average patient remained on therapy for at least 1 year after treatment initiation, which was used to estimate time-depended treatment-related costs. The probability of progression within 1 year of treatment initiation was used to inform the average postprogression therapy costs for each regimen. RESULTS: The estimated cost per patient for each triplet regimen was $13,890 (DARA/BOR/DEX), $22,231 (IXA/LEN/DEX), $24,322 (ELO/LEN/DEX), $26,410 (DARA/LEN/DEX), and $27,432 (CAR/LEN/DEX). Drug acquisition costs and treatment duration were the largest drivers of cost. Scenario analyses with plausible alternative input parameters found the maximum per month cost of therapy to be $30,657 (CAR/LEN/DEX) and the minimum per month cost of therapy to be $13,784 (DARA/BOR/DEX). CONCLUSIONS: This analysis controlled for differential utilization rates for 5 FDA-approved, NCCN-recommended triplet therapies for the treatment of previously treated MM. Of the examined regimens, treatment with DARA/BOR/DEX was estimated to have the lowest average monthly cost per patient, while CAR/LEN/DEX was the most expensive. As is common with modeling, some assumptions were necessary, and results may not be generalizable. Copyright (C) 2019, Academy of Managed Care Pharmacy. All rights reserved.