
German healthcare giant Boehringer Ingelheim has announced that its drug iclepertin, designed for patients living with cognitive impairment as a result of schizophrenia, has missed all primary and secondary endpoints in three Phase III studies.
The company said its Phase III CONNEX clinical trial programme saw no statistically significant effects on cognition or functioning observed in patients treated with iclepertin versus placebo at six months. Despite this, the company says the drug showed a favourable safety profile.
The CONNEX trial was a Phase III programme made up of three separate trials examining iclepertin for improving cognitive impairment in adults with schizophrenia. CONNEX-1 (NCT04846868), CONNEX-2 (NCT04846881) and CONNEX-3 (NCT04860830) all enrolled more than 1,840 patients across 41 countries. All three trials were randomised, double-blind, placebo-controlled parallel group trials investigating treatment with oral iclepertin 10mg once daily 26-weeks in adults with schizophrenia who received stable antipsychotic treatment.
Boehringer Ingelheim describes iclepertin as an investigational oral inhibitor of glycine transporter (GlyT1).
Shashank Deshpande, head of human pharma at Boehringer Ingelheim, said: “While these findings are disappointing, we remain dedicated to finding effective solutions for those living with serious mental illnesses. Our innovative pipeline includes over 20 additional investigative therapies in all stages of development and in different disease areas including schizophrenia and major depressive disorder.”
Research by the World Health Organization (WHO) estimates that there are approximately 24 million people – one in 300 people – worldwide living with some form of schizophrenia. At the same time, the body estimates that people with schizophrenia are two to three times more likely to die early than the general population due to physical illnesses, such as cardiovascular, metabolic, and infectious diseases.

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By GlobalDataResearch by GlobalData estimates that by the end of 2030, the global market for drugs aimed specifically at tackling cognitive impairment as a result of schizophrenia will be worth $429m, up from an estimated value of just $25m by the end of 2025.
GlobalData is the parent company of Clinical Trials Arena.
Elsewhere in the field of schizophrenia treatment, AbbVie’s stock price fell more than 12% after emraclidine failed to meet its primary endpoints in the company’s Phase II programme. Meanwhile, Chinese-American company Zai Lab has reported positive outcomes from its Phase III clinical trial of KarXT (xanomeline and trospium chloride) in China.