Johnson & Johnson has been unable to convince the US Food and Drug Administration that its antipsychotic drug Risperdal (risperidone) is effective in a new indication, psychosis in patients with Alzheimer’s disease.

This is the second knockback for the drug in under a week. On May 20, J&J received a not approvable letter from the FDA for Risperdal in the treatment of autism [[23/05/05c]].

The FDA issued a “not approvable” notice to J&J for Risperdal in the Alzheimer’s-related psychosis indication yesterday. This is a real disappointment for the company, as psychosis is estimated to affect upwards of 30% of the 4 million Alzheimer’s patients in the US, and could have represented a significant new market opportunity for the drug, although off-label use is thought to be fairly common.

Details of the objections raised in the letter are not yet available, but could relate to an FDA determination that patients with dementia-related psychosis, treated off-label with atypical antipsychotics, including Risperdal, are at an increased risk of death compared to placebo [[12/04/05a]].

J&J said it would be discussing with the FDA how to proceed with the application for Risperdal in Alzheimer’s psychosis, given the unmet medical need in this setting. Alzheimer’s patients who also develop psychosis tend to suffer more profound cognitive deficits and deteriorate more quickly.

Risperdal is currently approved to treat schizophrenia and bipolar disorder, and J&J has been trying to expand its indications both to differentiate the drug from competition in the atypical antipsychotic class and diminish the impact of generic competition, which could arrive as early as next year, according to Datamonitor [[08/02/05g]].

Risperdal sales topped $3 billion dollars last year [[26/01/05c]], but it is jostling for market share in an increasingly crowded segment with Eli Lilly’s top-selling Zyprexa (olanzapine), AstraZeneca’s Seroquel (quetiapine), Pfizer’s Geodon (ziprasidone) and Bristol-Myers Squibb’s Abilify (aripiprazole).