Although the secretin drug, RG1068, proved ineffective in treating positive symptoms of the disease during a previous phase II trial, several patients showed cognitive improvements following drug administration. Results of the patients tested on specific cognitive tasks two hours following drug administration were deemed sufficient to warrant further investigation.
The present study is being conducted to attempt to reproduce the finding that secretin may have had an impact on a specific cognitive deficit in schizophrenia. Secretin is a digestion-stimulating hormone produced in the small intestine.
Cognitive deficits are now recognized as a primary and enduring feature of schizophrenia; one which often precludes patients from gaining employment. Historically, drug makers have been particularly interested in controlling the positive symptoms of schizophrenia, delusions and hallucinations, leading to typical antipsychotics which merely suppressed these outward symptoms. Recently more attention has focused on also combating cognitive deficits associated with the disease.
Some atypical antipsychotics have demonstrated efficacy at treating cognitive deficits in specific domains of cognition, for example risperidone (Johnson & Johnson’s Risperdal) can aid performance of working memory tasks while clozapine can improve semantic memory. However, treatments have yet to restore full cognitive functioning to patients suffering from the disease.
The Repligen study will evaluate 30 patients who will be assigned to one of two groups who will either receive placebo or RG1068. Additional assessments will be made on the patients to investigate the effects of RG1068 on information processing and affect modulation. If the study helps further uncover the neurochemistry of the drug effects, it may lead to a clearer picture of the cognitive deficits associated with schizophrenia and how to treat them.