Review of the Trace Amine-Associated Receptor 1 (TAAR1) Agonist Ulotaront: Part II—Summary of Initial Clinical Efficacy/Safety Results

Abstract

AbstractIntroductionUlotaront is a trace amine-associated receptor 1 (TAAR1) agonist with serotonin 5-HT1A agonist activity that has received FDA Breakthrough Therapy Designation for the treatment of schizophrenia. Here we summarize ongoing clinical research characterizing the efficacy and safety of ulotaront as a member of the novel trace amine-associated receptor 1 (TAAR1) agonist class.MethodsSummarized are results from a double-blind, placebo-controlled study to evaluate the efficacy and safety of ulotaront (50 mg or 75 mg) in an acute exacerbation of schizophrenia, and a 6-month, open-label follow-up study. Also summarized are post-hoc analyses evaluating negative symptom efficacy, and key safety and adverse event (AE) outcomes.ResultsIn the short-term study, treatment with ulotaront was associated with significant (p<0.001) endpoint improvement in the PANSS total score (effect size [ES]: 0.45), the CGI-Severity score (ES: 0.52) and the Brief Negative Symptom Scale total score (ES: 0.48). The incidence of any AE was lower on ulotaront versus placebo (45.8% vs. 50.4%), and the number needed to harm (NNH) for individual AEs on ulotaront were all >40. Ulotaront was associated with lower risk for antipsychotic class-related AEs (extrapyramidal symptoms, akathisia, somnolence, nausea/vomiting, increased weight/metabolic labs, prolactinemia). The 6-month study demonstrated further improvement, with a completion rate (67%) that was higher than reported for current dopamine D2 antipsychotics.ConclusionsThe emerging profile of ulotaront is characterized by significant improvement in positive and negative symptoms of schizophrenia. The safety and tolerability profile of ulotaront is markedly different with respect to antipsychotic class-related AEs. The benefit-risk profile of ulotaront, as a member of a novel TAAR1 agonist class, is distinguished from antipsychotics by lack of AEs related to D2 and serotonin 5-HT2A receptor blockade.FundingSunovion Pharmaceuticals, Inc., and Otsuka Pharmaceutical Development & Commercialization, Inc.