Johnson & Johnson has received an ‘approvable’ letter from US the Food and Drug Administration for its paliperidone extended-release tablets, requesting additional information on the drug for schizophrenia.

J&J applied for FDA approval of paliperidone ER in November 2005. The company said it will work quickly to resolve any of the FDA's questions for the product, which is a follow-up to its blockbuster Risperdal (risperidone), which is getting a little long in the tooth and facing intense competition from drugs such as Eli Lilly's top-selling Zyprexa (olanzapine), AstraZeneca's Seroquel (quetiapine) Pfizer's Geodon (ziprasidone) and Bristol-Myers Squibb's Abilify (aripiprazole).

J&J will be hoping that it can resolve the outstanding issues with the FDA promptly, as Risperdal could face generic competition as early as next year in the important US market. The drug had revenues of $1.15 billion in the first six months of the year, a rise of 21% over the same period of 2005.

Paliperidone uses a drug delivery technology developed by Alza, another J&J subsidiary, called OROS, which releases drug into the bloodstream steadily over a 24-hour period. The delivery technology is designed to avoid the peaks and troughs of drug levels in the blood that occur with other antipsychotics and, hopefully, lead to improved control of symptoms.