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Phase III Study of Secretin for Autism Fails To Meet Primary Endpoints
WALTHAM, Mass., Jan. 5 /PRNewswire-FirstCall/ -- Repligen Corporation announced today that its Phase 3 clinical trial in autism of RG1068, synthetic human secretin, failed to meet the study's dual primary endpoints, improvements in social interaction as measured by the Autism Diagnostic Observation Schedule ("ADOS") and the parental Clinical Global Impression of Change ("CGI"). The Phase 3 study had a higher placebo effect than was observed in the Phase 2 study and neither endpoint showed a significant treatment effect in the entire group. A prospectively defined subset analysis of the higher functioning patients (n=68) showed a statistically significant improvement of RG1068 versus placebo on ADOS but not on the CGI. This finding may indicate that measuring a response to RG1068 is more difficult in patients with lower levels of cognitive function. A preliminary review of the safety data showed no clinically meaningful differences between RG1068 and placebo in side effects and there were no serious adverse events observed in the Phase 3 trial.
This study was a double-blind, placebo-controlled, clinical trial which evaluated 132 children aged 2 years 8 months to 4 years 11 months with moderate to severe symptoms of autism. Each patient was comprehensively evaluated at baseline, received six injections of RG1068 or a placebo over 18 weeks and was then reevaluated for improvements in the symptoms of autism. The primary endpoints were improvements in reciprocal social interaction as measured by ADOS, which is performed by a trained psychologist, and the parental CGI. The trial was carried out at 15 medical centers in the United States.
"We would like to thank the patients, their parents and the clinicians for their participation and support in this study," stated Walter C. Herlihy, President and Chief Executive Officer of Repligen. "We have developed an extensive preclinical and clinical data set which supports the use of secretin in the treatment of other neuropsychiatric diseases and we plan to continue our efforts to develop secretin for schizophrenia. Future development in autism will be dependent on a thorough evaluation of the Phase 3 data and discussions with the Food and Drug Administration."
Repligen is currently conducting a Phase 2, double-blind, placebo- controlled, clinical trial to evaluate RG1068 in patients with refractory schizophrenia. This trial will evaluate the potential of multiple doses of RG1068 to treat the deficits in social cognition in schizophrenia, including social interaction and communication deficits ("negative" symptoms), which are generally resistant to treatment with existing antipsychotic therapy. Additionally, Repligen intends to initiate a study of RG1068 in an anxiety disorder in the second half of 2004.
Schizophrenia is a serious and chronic neuropsychiatric disorder that affects 2 million people in the United States. This devastating condition interferes with a person's ability to think clearly, separate fantasy from reality, manage emotions and relate to others. Patients with schizophrenia suffer from "positive" symptoms including hallucinations, delusions, and disorganized speech and behavior, as well as "negative" symptoms such as lack of drive and initiative, social withdrawal and blunting of emotional expression. Deficits in social cognition are present at all stages of the disease, contribute to the rate of relapse and are predictive of long-term outcome. Current treatment with antipsychotic therapy is generally directed at control of positive symptoms. Even when successful, antipsychotic therapy has limited impact on negative symptoms, and severe residual and incapacitating social and emotional deficits may persist. Sales of antipsychotic drugs for schizophrenia including Zyprexa™, Risperdal™ and Geodon™ totaled approximately $5 billion in the United States in 2002. The total cost for the care and treatment of patients with schizophrenia in the United States in 2000 was approximately $40 billion.
About Anxiety Disorders
Anxiety disorders are serious medical illnesses that affect approximately 20 million adults in the United States. These disorders include generalized anxiety disorder, social anxiety disorder, post traumatic stress disorder, panic disorder and obsessive-compulsive disorder. Symptoms of anxiety disorders can significantly impact normal function including intense fear, overwhelming anxiety and excessive embarrassment or humiliation by one's own actions. Although conventional antidepressant and antianxiety drugs can be effective in some patients they typically lead to adverse side effects that can include sedation, cognitive impairment and appetite stimulation. The new biology of secretin may provide an alternative for patients who are refractory to other drug therapies.
Source: Repligen Corp.