Pipeline antipsychotic drugs to drive next market growth, says Datamonitor

Atypical antipsychotics will be the engine that drives growth in this developed market, according to Datamonitor. With a global value of around US$22bn in 2008 - and the leading drug class in the US - the commercial opportunity for antipsychotics is considerable.

Since the introduction of clozapine, the first atypical antipsychotic to treat schizophrenia, the growth of this class of drugs has been rapid. Offering improved efficacy, tolerability and a superior side-effects profile than typical antipsychotics, the launch of atypical antipsychotics has evolved the treatment of schizophrenia, the data analyst says.

However, the real growth driver has been a change in attitude to using antipsychotics and expansion into different indications such as schizoaffective disorder, anxiety and depression.

AstraZeneca's Seroquel (quetiapine) and Eli Lilly's Zyprexa (olanzapine), for example, became the biggest-selling antipsychotics in 2008 with global sales of US$5.5bn and US$5.4bn respectively.

Saphris's FDA advisory board backing for both schizophrenia and bipolar disorder is significant, according to Datamonitor, as bipolar disorder is a larger market by prescribing than schizophrenia.

"Sales in bipolar disorder will be critical to the drug's success," says Datamonitor's central nervous system analyst Trung Huynh. "In this increasingly competitive environment, new market entrants need to stand out to make a significant impact on established brands and generic antipsychotics and despite a favourable side-effect profile, Saphris has only comparable efficacy and a similar mechanism of action to that of the existing brands."

Datamonitor forecasts sales of around US$600m by 2013, after which Saphris will be competing with generic versions of leading brands Zyprexa and Seroquel.

As a leading antipsychotic developer, Johnson & Johnson has the experience and network to launch Invega Sustenna, recently approved by the US FDA, in this competitive market. Additionally, doctors are already familiar with the company's Rispersal Oral, Risperdal Consta and Invega.

Merck's agreement to buy Schering-Plough for $42bn will undoubtedly aid market penetration and the launch of Saphris. Conversely, following negative efficacy results in Phase III clinical trials for acute schizophrenia, Lundbeck cancelled its bifeprunox partnership with Solvay. Some hope for Solvay remains in the drug's potential for the maintenance treatment for schizophrenia, however the company would need a partner to help develop and launch bifeprunox in the US, says Datamonitor.

Japanese pharmaceutical company Dainippon Sumitomo is also searching for partners to break into the European and US markets with its pipeline antipsychotic lurasidone, while Vanda Pharmaceuticals is seeking a partner or buy out to help facilitate the launch of FDA-approved Fanapt (IIloperidone).

"Ultimately, the challenge for developers is innovation in terms of efficacy, tolerability and compliance to convince psychiatrists to prescribe new antipsychotics instead of established brands in the near term, and generic versions of these brands from 2012 onwards," concludes Datamonitor.