Johnson & Johnson has presented the results of two Phase III studies showing that its once-daily antipsychotic drug paliperidone is significantly more effective in the treatment of schizophrenia than placebo.

J&J filed for approval of paliperidone, which uses an extended-release technology developed by its Alza drug delivery unit, last month. 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.

The two studies revealed that paliperidone achieved significant improvements in patient scores on the Positive and Negative Syndrome Scale (PANSS), a standard measure of drug efficacy in schizophrenia, compared to placebo. The drug also demonstrated improvement in personal and social functioning, an important treatment goal in assessing patients' progress, said J&J.

If approved, paliperidone will be a successor to J&J’s Risperdal (risperidone) schizophrenia drug, which posted sales of $3 billion dollars last year but 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).

Risperdal could face generic competition as early as next year in the important US market, so paliperidone could help J&J support its schizophrenia franchise in the face of a likely rapid tail-off in Risperdal sales.