Feature
Schizophrenia researchers seek elusive ‘quantum leap’
Treatment for schizophrenia has not advanced much in decades, but a neurotransmitter is shedding secrets.
PARIS – The oral selective glutamate inhibitor evenamide is moving on to advanced clinical trials on the strength of positive results in a phase 2 study, Ravi Anand, MD, reported at the annual congress of the European College of Neuropsychopharmacology.
Evenamide is a highly selective inhibitor of voltage-gated sodium channels that also attenuates glutamate release by hyperexcited neurons, explained Dr. Anand, chief medical officer at Newron Pharmaceuticals, a company based in Bresso, Italy, that is developing this novel antipsychotic agent.
The 4-week, randomized, double-blind, placebo-controlled, multicenter study included 89 patients with schizophrenia of a mean 18 years’ duration. All participants showed baseline evidence of breakthrough psychosis despite being on stable therapeutic doses of previously effective risperidone or aripiprazole. They were randomized either to add-on oral evenamide at a starting dose of 15 mg twice daily titrated to 20 or 25 mg twice daily or to placebo.
As a phase 2 study, the primary focus was on safety and tolerability. Evenamide showed no dose-limiting toxicities. Nor did those in the evenamide group experience any of the common dopaminergic side effects seen with currently available antipsychotics, such as sedation, weight gain, sexual dysfunction, cardiac abnormalities, or extrapyramidal symptoms.
The only adverse events more common in the evenamide-treated group than in placebo-treated controls were insomnia and headache, which occurred in 5 and 3 of the 50 patients on evenamide, respectively.
In terms of efficacy, 75% of the evenamide group showed improvement over baseline in terms of the Positive and Negative Syndrome Scale, compared with 44% of controls. From a mean baseline total PANSS score of 62.7, the evenamide group experienced a 5.1-point reduction at day 28, compared with a 3.7-point improvement in controls. The difference between the two study arms was already significant at the first assessment, which took place on day 8.
Furthermore, 55% of patients in the evenamide group showed significant improvement on the Clinical Global Impression Severity score, compared with 36% of controls.
Because evenamide’s efficacy was greater in younger patients, the next round of larger, longer clinical trials will focus on younger patients with more severe symptoms, Dr. Anand said.