Bristol Myers presents new interim long-term efficacy data from EMERGENT-4 trial

Bristol Myers announced new interim results from the Phase 3 EMERGENT-4 open-label extension trial evaluating the long-term efficacy, safety and tolerability of KarXT in adults with schizophrenia. Long-term efficacy data from the trial were presented in a poster titled, “Maintenance of Efficacy of KarXT (Xanomeline and Trospium) in Schizophrenia” at the Annual Congress of the Schizophrenia International Research Society being held April 3-7, 2024, in Florence, Italy. EMERGENT-4 is a Phase 3, 52-week, outpatient, open-label extension study evaluating the long-term safety, tolerability, and efficacy of KarXT in adults with schizophrenia who previously completed the treatment period of one of the Phase 3, five-week, double-blind, placebo-controlled, efficacy and safety studies, EMERGENT-2 or EMERGENT-3. At the time of the data cutoff of April 17, 2023, 110 patients were part of the interim efficacy analysis, with 29 patients having completed 52 weeks of treatment. In the interim analysis, KarXT was associated with significant improvement in symptoms of schizophrenia across all efficacy measures at 52 weeks. At the end of the open-label extension, more than 75% of participants achieved greater than30% improvement in symptoms, with an average reduction of 33.3-points from baseline, as measured by the Positive and Negative Syndrome Scale total score. In addition, participants had a mean 1.7-point change in Clinical Global Impression-Severity score from baseline, representing an average shift from “markedly ill” at baseline to “moderately” or “mildly” ill at one year. Improvements in symptoms of schizophrenia continued throughout the 52-week trial regardless of whether participants were previously treated with KarXT or placebo during the acute trials. Prior to enrolling in the open-label extension, participants who previously received placebo in EMERGENT-2 and EMERGENT-3 had a significantly higher mean PANSS total score compared to those who received KarXT. When dosed with KarXT, the patients previously on placebo had significant improvements in symptoms within two weeks of treatment with KarXT. After four weeks, PANSS total scores were comparable between those who received KarXT or placebo in the acute trials. In additional data presented at the congress, KarXT demonstrated a favorable impact on weight and long-term metabolic profile where most patients experienced stability or improvements on metabolic parameters over 52 weeks of treatment. In long-term trials, KarXT was generally well tolerated, with a side effect profile consistent with prior trials of KarXT in schizophrenia. KarXT was not associated with significant changes related to prolactin or clinically meaningful changes in movement disorder scale