Increased generic erosion of key drugs used in the treatment of bipolardisorder, and of leading products in the atypical antipsychotic drug class,will cause the market to plummet $2.3 billion over the next decade, a newreport forecasts.

Leading products which are expected to be particularly hit by genericcompetition include GlaxoSmithKline’s Lamictal (lamotrigine) andAbbott/Sanofi-Aventis’s Depakote/Abbott’s Depakote ER (divalproex), accordingto the study, from Decision Resources.

Patient share for atypical antipsychotics will increase through 2019,particularly in France, Germany, Italy, Spain, the UK and Japan, the reportforecasts. However, it adds that sales of these products will declinesignificantly over the forecast period as a result of the generic erosion ofkey agents such as AstraZeneca/Astellas’ Seroquel/AstraZeneca’s Seroquel XR(quietapine fumarate), Eli Lilly’s Zyprexa olanzapine), Bristol-MyersSquibb/Otsuka Pharmaceutical’s Abilify (aripiprazole) and Pfizer’s Geodon(ziprazidone).__

Bipolar depression remains the largest unmet need in the treatment ofbipolar disorder, with research continuing to show that that few therapies areable achieve sufficient efficacy for this condition, according to the report.It goes on to forecast that two emerging atypical antipsychotics - ForestLaboratories/Gedeon Richter/Mitsubishi Pharma’s cariprazine and DainipponSumitomo Pharma/Sepracor’s lurasidone (SM-13,396) - are likely to gain approvalfor bipolar depression. Moreover, it says that lurasidone, for which a new DrugApplication (NDA) was submitted to the US Food and Drug Administration (FDA)for the treatment of schizophrenia last December 30, will become a marketleader in 2019. _

“The bipolar depression market segment represents the greatestcommercial opportunity and we expect that lurasidone will gain approval forbipolar depression in 2012, following its launch in 2011 for the treatment ofschizophrenia,” says Alana Simorellis, an analyst at Decision Resources.

According to Dr Simorellis, Dainippon Sumitomo Pharma and Sepracor willdifferentiate lurasidone based on its efficacy in bipolar depression, as wellas its potential for efficacy in cognitive symptoms and its relatively mildweight gain profile compared with currently marketed atypical antipsychotics.

“As a result, we forecast lurasidone to garner peak year sales in therange of $500 million to $1 billion,” she says.