More MS news articles for July 2002

Phase II/III Clinical Trial of Neurodex Completed

Jul. 11, 2002

Avanir Pharmaceuticals (AVN) announced the completion of a phase II/III clinical trial investigating the safety and effectiveness of Neurodex in treating emotional lability in 116 patients with amyotrophic lateral sclerosis (ALS).

Emotional lability, also known as pseudobulbar affect or pathological laughing or crying, is a symptom complex experienced by an estimated one million patients with neurological conditions such as ALS or Lou Gehrig disease, Alzheimer disease, multiple sclerosis (MS), stroke and traumatic brain injury. Neurodex is the first drug product in clinical development specifically intended to treat emotional lability.

Neurodex is a patented, orally administered combination of dextromethorphan (DM) and an enzyme inhibitor that sustains elevated levels of DM in the human body. Results of a pilot study showed that the combination of DM, known to be an NMDA receptor antagonist, and an enzyme inhibitor resulted in higher and prolonged dextromethorphan blood levels. Patients in the phase II/III clinical trial were treated orally twice a day, on a 12-hour dosing schedule.

"While dextromethorphan is considered to be neuroprotective, the therapeutic dilemma has been that its rapid metabolism requires extremely high doses to attain optimum therapeutic benefit," said Avanir president and CEO Gerald J. Yakatan, PhD "We believe Neurodex allows for improved delivery by increasing blood levels for an extended timeframe with small doses. Side effects of Neurodex may be fewer than with high doses of dextromethorphan alone."

ALS involves loss of upper motor neurons in the brain, which control lower motor neurons. The term pseudobulbar palsy is used to describe uncontrolled activity of the lower motor neurons of the bulbar (brainstem) region and is a phenomenon that seems to cause laughing and crying not necessarily associated with emotions. The loss of the upper motor neurons also results in loss of control of these physical manifestations of emotion. Episodes of uncontrolled laughing and crying can be embarrassing and even frightening to patients and their caregivers.

To determine suitability for inclusion in the trial, patients were assessed for pseudobulbar affect by clinical observation and a survey called the CNS Lability Scale (CNS-LS). The CNS-LS is a validated survey that measures frequency and severity of emotional lability-related episodes. The double-blind, controlled, multicenter clinical trial studied three patient groups consisting of patients taking Neurodex, patients taking dextromethorphan alone, and patients taking the enzyme inhibitor alone. Endpoints of the study include a comparison to baseline of average CNS-LS scores between the Neurodex and other treatment groups and comparison of the number of emotional lability episodes. The phase II/III trial was conducted at 18 study sites in the U.S. including Baylor College of Medicine, Houston, Texas, the University of Wisconsin at Madison, the University of California at San Francisco, the University of Miami, Columbia-Presbyterian Medical Center, Pennsylvania Neurological Institute, Northwestern Medical School, and Massachusetts General Hospital.

"We anticipate obtaining final data and releasing the results of this study in July," continued Yakatan. "If successful, we plan to initiate a pivotal phase III clinical trial with MS patients. An open-label safety study will follow the MS trial and will include patients with symptoms of emotional lability occurring in stroke, Alzheimer disease, ALS or MS."

Avanir has the exclusive license to develop, manufacture, and market Neurodex for four potential indications: emotional lability, neuropathic pain, chronic cough, and weaning drug-dependent patients from narcotics and antidepressants. Avanir intends to initiate a phase II clinical trial examining Neurodex in the treatment of neuropathic pain later this year. Neurodex is protected by six issued U.S. patents. This article was prepared by Biotech Week editors from staff and other reports.

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