A 6-month extension of a short-term trial published earlier this year in The New England Journal of Medicine showed continued improvement with SEP-363856 in patients with schizophrenia, without adverse effects reported with typical and atypical antipsychotic drugs. Researchers presented the findings in a poster at Psych Congress 2020.
“SEP-363856 is a novel non-D2 receptor antagonist, and preclinical data suggest that agonism at trace amine associated receptor 1 (TAAR1) and the serotonin 5-H1A receptor contributes to its efficacy,” researchers wrote. “In a previous double-blind, placebo-controlled study, SEP-363856 demonstrated significant efficacy in the treatment of an acute exacerbation of schizophrenia.”
The 6-month open-label extension phase that followed the 4-week double-blind trial investigated the safety and effectiveness of longer-term treatment with SEP-363856.
Among 156 patients who started in the extension phase, 66.9% completed the 6 months of treatment. Reasons for discontinuation included adverse events (11.5%), withdrawal of consent (10.2%), and lack of efficacy (5.1%), according to the poster abstract. Adverse events affecting 5% or more of participants included headache (11.5%), insomnia (8.3%), and anxiety (5.1%).
Researchers observed no clinically meaningful changes on movement scales, metabolic laboratory parameters, or prolactin levels in participants. From double-blind baseline through the end of the 6-month extension phase, the average change in weight was -0.3 kilograms, researchers reported.
Throughout the open-label extension phase, participants showed continued improvement on the Positive and Negative Syndrome Scale (PANSS), with a mean total score decrease of 19.8 points.
“Up to 26 weeks of treatment with SEP-363856 had minimal effects on weight, metabolic parameters, prolactin, or extrapyramidal symptoms,” researchers concluded. “SEP-363856 was associated with continued improvement from open-label baseline in the PANSS total score.”
Sunovion Pharmaceuticals Inc. sponsored the study.
Koblan KS, Hopkins S, Kent J, Cheng H, Goldman R, Loebel A. Safety and effectiveness of SEP-363856 in schizophrenia: results of a 6-month, open-label extension study. Poster presented at Psych Congress 2020 Virtual Experience; September 10-13, 2020.