Antipsychotics are central nervous system therapies used to treat diseases such as schizophrenia or bipolar disorder. Patients with schizophrenia may hear "voices" or have strange thoughts that are "out of touch" with reality that can hamper their ability to carry out normal day-to-day life. Patients with bipolar disorder are characterized by mood changes that cycle between "high" manic moments and "low" depression moments. Together, the antipsychotic and antimaniac drug markets represent approximately 5 million people and generated revenues of $17.4 billion in 2008, a decline of 4% from 2007 largely driven by increased competition from lower priced generic drugs.
The major players in the antipsychotics market include AstraZeneca, Bristol-Myers Squibb, Eli Lilly, Pfizer, Johnson & Johnson, and GlaxoSmithKline. Eli Lilly's Zyprexa has the largest market share of the market, at 26% ($4.70 billion), while AstraZeneca's Seroquel, at 2nd place ($4.45 billion) remains the most widely prescribed antipsychotic. Bristol-Myers Squibb's Abilify, which was approved for market release in 2007, saw a 30% growth in sales from 2007 to 2008 to $2.15 billion, making it the fastest growing therapeutic in the antipsychotics market. Moreover, data that Abilify may carry less of a risk for weight gain and diabetes than the incumbent therapies is driving its push for increased market share.
The antipsychotic drug market is treatened by loss of exclusivity from patent expirations. By 2012, four of the six largest antipsychotic therapies will lose their patents and see revenues decreased by generic competition. However, this threat to market size may be offset if Abilify and other novel antipsychotic therapies are shown to carry reduced risks for weight gain and diabetes.
Zyprexa earned revenues of $4.70 billion in 2008, representing 23% of Eli Lilly's total earnings in that year. Total sales for Zyprexa decreased 1% from 2007 to 2008, due to decreased demand from increased generic competition. Zyprexa was approved in 2000 to treat schizophrenia. Eli Lilly's patent for Zyprexa expires on April 23, 2011.
Seroquel earned revenues of $4.45 billion in 2008, a growth of 9% from 2007 with sales driven by higher demand. Seroquel was originally approved in 1997 to treat patients with schizophrenia and is available in extended release tablets under the label, Seroquel XR, which only requires once-daily doses. Regulatory submissions are underway to gain approval for Seroquel as a treatment for major depressive disorder and bipolar disorder. As of 2007, Seroquel remains the most commonly prescribed atypical anti-psychotic in the US.
In February of 2009, AstraZeneca came under fire for allegations that they failed to warn physicians that Seroquel carries risks of weight gain and diabetes for prescribed patients. 9,000 lawsuits involving 15,000 patients have been filed regarding this case. AstraZeneca's patent on Seroquel expires on September 26, 2011.
Abilify earned revenues of $2.15 billion in 2008 for a growth of 30% from 2007 to 2008, driven by both higher demand and higher selling prices. Abilify was approved in 2007 as an adjunctive treatment for major depressive disorder as well as a therapeutic for schizophrenia and bipolar disorder in adolescents. BMS's patent on Abilify expires on October 20, 2014.
J&J's antipsychotics franchise, including the Risperdal formulations and Invega, earned revenues of $3.8 billion in 2008, a decrease of 24% from 2007 to 2008. Risperdal lost its patent exclusivity in March 2007, and has since seen sales decline substantially.
Invega was approved in 2007 by the FDA to treat schizophrenia. Invega contains a metabolite of the active ingredient of Risperdal in a controlled release formulation and has been criticized as not being any different from its predecessor. J&J retains exclusivity for Invega until April 27, 2010.
Lamictal earned revenues of $1.27 billion in 2008 for a decrease of 16% from 2007 to 2008. In June of 2003, Lamictal was approved to treat bipolar disorder in adults, making it the first pharmaceutical since lithium to be approved by the FDA for bipolar disorder.
Lamictal lost its exclusivity in July of 2008, and Taro Pharmaceutical's generic version was approved by the FDA in February of 2009. The increased competition will lead to a decrease in sales of Lamictal.
Geodon earned revenues of $1.01 billion in 2008 for a growth of 18% from 2007 to 2008. Geodon (marketed outside the U.S. as Zeldox) is approved for the treatment of schizophrenia as well as acute mania and mixed episodes associated with bipolar disorder. Geodon is currently in development to treat Bipolar disorder. Pfizer's patents on Geodon expire on March 2, 2012.
|Rank||Market Share||Company||Product||Revenue ($ billion)||Growth|
|3||22%||Johnson & Johnson||Risperdal||3.8||(-24%)|
In 2003, the FDA required all manufacturers of atypical antipsychotics (including Risperdal, Geodon, Zyprexa, Seroquel, and Abilify) to add a warning to their drug labels that use of such drugs increases risk of hyperglycemia and diabetes mellitus. The risk of weight gain and diabetes among patients receiving atypical antipsychotics has been well documented and has arisen as a significant controversy in the antipsychotic drug market.
Abilify, while newer to the market and with fewer studies done of its association with weight gain compared with more incumbent antipsychotics, may carry less of a risk for weight gain. Abilify's emergence in the antipsychotics market as well as the discovery and development of novel antipsychotics that do not carry significant risks for weight gain may offset the decrease in market size due to generics in the antipsychotics market.
Patent expirations of two blockbuster antipsychotic medications, Risperdal and Lamictal, have already encouraged the appearance of cheap generics on the market. The appearance of generics for a therapeutic introduces competition into the market and substantially drives down the prices of those therapeutics. Several major drugs in the antipsychotic market have patent expiration dates before 2012, including Zyprexa (April 23, 2011), Seroquel (September 26, 2011), and Invega (April 27, 2010). When these therapeutics lose patent exclusivity, generics will offer psychiatrists a wide variety of cheap medications to prescribe, substantially decreasing the size of the antipsychotics market.