A new schizophrenia drug has moved closer to the market after a US advisory panel gave its backing to Schering-Plough’s Saphris.

The US Food and Drug Administration’s Psychopharmacologic Drugs Advisory Committee voted unanimously that Saphris (asenapine), a sublingual tablet is an effective and safe treatment of manic or mixed episodes associated with bipolar I disorder. The panellists also backed the drug for its use for the acute treatment of schizophrenia in adults, and if approved Saphris would be the “first psychotropic drug to be approved initially for both of these indications”, S-P noted.

The New Drug Application for Saphris includes efficacy data from more than 3,000 patients in schizophrenia and bipolar mania trials, and is supported by safety data in 4,500 patients, with some treated for more than two years. Thomas Koestler, president of Schering-Plough Research Institute, noted that asenapine has demonstrated efficacy “combined with an attractive metabolic safety profile” and “has the potential to address a significant unmet need for patients”, including those who need options when switching or re-initiating therapy.

S-P has previously stated that Saphris, which was acquired in November 2007 through the acquisition of Organon BioSciences, could be a blockbuster. It was filed with the European Medicines Agency last month under the brand name Sycrest.

If approved, Saphris will join other atypical antipsychotics on the market, such as Johnson & Johnson's (risperidone) and Eli Lilly's Zyprexa (olanzapine). However, many observers believe that S-P’s drug offers more than existing treatments.

Jon LeCroy, an analyst at Natixis Bleichroeder, issued an investor note saying that “we believe that the opportunity for Saphris is under-appreciated”. He added that “we think an antipsychotic with little to no weight gain and no cardiovascular safety issues is a lay-up blockbuster”.