Schering-Plough says that regulators in the USA have agreed to look at the firm’s New Drug Application for asenapine, which the company acquired last week through its purchase of Organon.

The firm said that the clinical trial programme being reviewed by the US Food and Drug Administration involving the drug, which is placed under the tongue and then dissolves, has consisted of schizophrenia and bipolar mania trials involving nearly 3,000 patients.

Foe example, Phase III data, presented at the American Psychiatric Association's annual meeting in San Diego in May revealed that asenapine significantly improved acute mania symptoms in patients with bipolar I disorder compared to placebo, and had a lower risk of weight gain than Eli Lilly's Zyprexa (olanzapine).

As part of the three-week study, 488 patients with bipolar I disorder experiencing mania or a mixed episode were randomised to three weeks of treatment with either asenapine twice-daily, Zyprexa once-daily, or placebo. 3.1% of patients who received asenapine reported weight gain, compared with 6.9% of those taking the Lilly drug and 1% of patients in the placebo group.

Previously, Organon was jointly developing asenapine with Pfizer before the drugs giant pulled out of the agreement last November, citing commercial interests. The compound is regarded as the most promising in the pipeline at Organon, which has just been sold to S-P by Akzo Nobel.