An investigational prescription digital therapeutic (PDT) designed to treat negative symptoms of schizophrenia has achieved its primary goal in a pivotal phase 3 study, according to developers Boehringer Ingelheim and Click Therapeutics.

The Convoke trial assessed CT-155, a smartphone-based intervention intended to be used alongside standard antipsychotic medicines. While current drugs can reduce hallucinations and delusions, they often have little impact on negative symptoms, which include diminished emotional expression, social withdrawal, and reduced motivation. These symptoms are associated with poorer functional outcomes and quality of life, and are considered one of the most challenging aspects of the illness to treat.

More than 1,000 adults with schizophrenia took part in the global, randomised, controlled study. Participants were assigned to receive either CT-155 plus usual care or usual care alone for a 12-week treatment period.

According to the companies, patients using CT-155 in addition to their prescribed medication showed a statistically significant improvement on the Negative Symptom Assessment-16 scale compared with the control group. Detailed numerical data were not released, but the findings are expected to be presented at an upcoming scientific meeting.

CT-155 delivers cognitive training exercises and behavioural strategies via a mobile app, with the aim of encouraging daily engagement and improving functional outcomes. The therapy is prescription-only and is designed to work in combination with clinical oversight, not as a stand-alone treatment.

The study’s outcome marks one of the first times a digital therapeutic has demonstrated efficacy for a core symptom cluster in schizophrenia in a large-scale trial. Negative symptoms have historically been difficult to address with pharmacological approaches, and the result may open the door to new avenues for treatment.

Boehringer Ingelheim and Click Therapeutics said they plan to engage with regulatory authorities to discuss next steps, including the potential submission of CT-155 for marketing authorisation. If approved, it would join a small but growing number of prescription digital therapeutics targeting psychiatric and neurological conditions.

Schizophrenia affects approximately 24 million people worldwide, according to the World Health Organization, with onset typically in early adulthood. Alongside positive symptoms such as delusions and hallucinations, negative symptoms can persist throughout life, placing a significant burden on patients, families, and health systems.