Generic erosion of atypical antipsychotics will cause the bipolar disorder drug market to decline by over $1 billion through 2018

Generic erosion of branded atypical antipsychotics will cause the bipolar disorder drug market to decline from $6.3 billion in 2008 to around $5 billion in 2018 in the world's leading pharmaceutical markets, the USA, France, Germany, Italy, Spain, the UK and Japan, according to new research from Decision Resources.

The new Pharmacor report, titled Bipolar Disorder, finds that the market will be constrained over the next several years by the patent expiries and subsequent generic erosion of key antipsychotic agents such as AstraZeneca's Seroquel (quetiapine), Eli Lilly's Zyprexa (olanzapine), Bristol-Myers Squibb/Otsuka's Abilify (Aripiprazole), and Pfizer's Geodon (ziprasidone HCI).

In 2008, sales of atypical antipsychotics exceeded $4 billion but generic competition, beginning in 2011, will cause sales of these agents to decline to just under $3 billion by 2018, according to the report. Additionally, patent expiries of branded antidepressants that include Wyeth's (now Pfizer's) Effexor XR (venlafaxine), Eli Lilly's Cymbalta/Xeristar (duloxetine) and Forest/Lundbeck's Lexapro/Cipralex (escitalopram) will further constrain the market.

"Despite the overall decline in the market, we forecast that sales for bipolar disorder therapies in Europe and Japan will grow modestly from 2008 to 2018," said Decision Resources analyst Alana Simorellis, adding: "Market growth in Europe and Japan will be due in part to the continued uptake of atypical antipsychotics and an increasing drug-treated population for the indication."

The report also finds that the expanded labeling for AstraZeneca's Seroquel/Seroquel XR to include bipolar maintenance and bipolar depression, as well as the potential approval of Dainippon Sumitomo's lurasidone for bipolar depression, will serve to differentiate these therapies from other atypical antipsychotics. Experts indicate that bipolar depression is difficult to treat, and there is substantial market opportunity for therapies that address this market segment, the report notes.