Results from the National Institutes of Mental Health CATIE (Clinical Antipsychotic Trials of Intervention Effectiveness) study, published in the September 22 issue of the New England Journal of Medicine, indicate that the 40-year old generic perphenazine is just as effective as its significantly more expensive branded peers in treating schizophrenia.

The study compared the effectiveness and side effects of the generic and four newer antipsychotics: Eli Lilly’s Zyprexa (olanzapine), Pfizer’s Geodon (ziprasidone), Johnson & Johnson’s Risperdral (risperidone) and AstraZeneca’s Seroquel (quetiapine), and found little difference in their efficacies compared to perphenazine.

"Surprisingly, the older, less expensive medication used in the study generally performed as well as the newer medications," the researchers noted, and pointed out that, “contrary to expectations, movement side effects - rigidity, stiff movements, tremor, and muscle restlessness - primarily associated with the older medications, were not seen more frequently with perphenazine...than with the newer drugs.”

Eli Lilly and Co’s Zyprexa, which was subject to the heaviest Industry scrutiny as it represents the top-selling atypical antipsychotic in the group with sales of $4.4 billion in 2004 (a substantial 32% of Lilly’s sales), fared better than the other agents in terms of discontinuation of therapy rates, although users experienced dramatic weight gain and developed a higher risk of diabetes. Patients taking the agent were less likely to require hospitalization for a psychotic relapse and tended to stay on the medication longer than those receiving other treatments.

Robert Baker, MD, medical director of US neuroscience at Lilly, commented that the findings are “important to patients and doctors because research shows that patients who stay on their medication generally have greater improvement in symptoms, reducing hospitalization and costs, and may function better in their daily lives.”

According to the study authors, 74% of schizophrenia patients discontinue their therapy, highlighting the difficulties in treating individuals with condition. The most common reason for discontinuation was the patient's own decision to stop taking their medication, underscoring the fact that patients need a variety of therapy options, because what works well for one may not be optimal for another.

“These findings emphasize the importance of patient- physician communication in maximizing treatment success,” stated Glenn Gormley, Chief Medical Officer at AstraZeneca. “Schizophrenia and its treatment are both complex. Patients are unique and respond to different drugs in different ways. As a result, no one antipsychotic medicine is best suited for all patients, underscoring the need for multiple treatment options,” he added.

The general feeling in the industry is that the CATIE results “are unlikely significantly affect trends in prescriptions in the market, especially considering that Bristol-Myers Squibb’s Abilify (aripiprazole) was not included in the evaluation, thereby minimizing the clinical significance of the study results, according to Morgan Stanley analyst Jami Rubin.