Cost-effectiveness analysis of xanomeline and trospium chloride for the treatment of adults with schizophrenia in the US

AIM: The objective of this analysis was to evaluate the cost-effectiveness of xanomeline and trospium chloride (KarXT) as first line (1 L) treatment for adults with schizophrenia from a third-party US payer perspective compared with commonly used antipsychotics, considering both costs and patient quality of life. METHODS: A decision tree-Markov hybrid approach was used to develop an economic model which included both acute and maintenance phases, accounting for probability of treatment response, discontinuation, relapse, adverse events, and death over a lifetime horizon. Clinical data were drawn from published trials, with costs and utilities coming from publicly available sources. Incremental cost-effectiveness ratios (ICERs) were calculated, and sensitivity and scenario analyses were performed to test the robustness of the results. RESULTS: In the base case analysis, KarXT was found to be more costly but more effective than common generic antipsychotics, yielding cost-effective ICERs, and less costly and more effective than branded antipsychotics. The model was associated with moderate sensitivity to treatment response inputs. Scenario analyses showed that implementation of a societal perspective, no tardive dyskinesia risk for KarXT, and a 50% reduction KarXT's relapse probability improved the cost-effectiveness of KarXT. Conversely, a 50% increase in KarXT's relapse probability and a second line analysis worsened cost-effectiveness. LIMITATIONS: At the time of the analysis, relapse data did not exist for KarXT therefore an average of other treatments was assumed and tested in a sensitivity analysis. Also, patients may receive multiple lines of therapy in a lifetime, however, the model only incorporated three lines of treatment. CONCLUSIONS: KarXT, the first schizophrenia medication in 70 years with a non-dopaminergic mechanism of action, is a valuable and potentially cost-effective 1 L treatment option, highlighting the need for continued innovation in this disease space.