According to the IMS National Sales Perspectives, antidepressants continued
to be big business in the United States in 2005.
Last year, antidepressants made the IMS Health list of the "Leading
20 Therapeutic Classes by U.S. Sales." SSRIs, for the fifth year in a
row, closed the year in sixth place, with $6.8 billion in sales. SNRIs came in
16th, with $3.4 billion in sales. All totaled, sales of all antidepressants
marketed in the U.S. funneled $12.5 billion into the coffers of pharmaceutical
The Pharmaceutical Research and Manufacturers of America, the industry's
trade group and lobbying arm, says that today's high drug prices fund
tomorrow's research and development. While many argue that high prices simply
translate into exorbitant profit margins, the high prices are at least in part
directly related to the need to develop new medicines.
Nearly 80 percent of last year's sales were rung up for the top five
branded antidepressants. Pfizer's Zoloft (sertraline) was again the top
seller, at $3.1 billion. Expiration of Pfizer's patents on Zoloft will allow
generic substitutes on the market as early as next month. To analysts'
surprise, the company has no clear successor.
Wyeth's Effexor XR (venlafaxine extended release) came in second, with
sales of $2.6 billion. Its patents don't expire until June 2010, but Wyeth is
reportedly hard at work on a replacement.
Third place went to Forest Labs' Lexapro (escitalopram) with $2.1 billion
in sales. Lexapro was designed as a replacement for Celexa (citalopram) when
the older drug's patents expired. Forest and development partner, Lundbeck,
announced earlier this year they were planning to conduct clinical trials of a
new antidepressant. Good timing: Lexapro loses patent protection in March
GlaxoSmithKline's Wellbutrin XL (bupropion extended release) came in
fourth, with sales of $1.5 billion. While the drug's patents don't expire
until 2018, long-running litigation challenging those patents make generic
versions likely by the end of 2007. GSK is pursuing several replacements.
In fifth place last year was the market's "youngest"
antidepressant: Eli Lilly's Cymbalta (duloxetine), with $667 million in sales.
With Cymbalta's patents set to expire in June 2008, Lilly is working on at
least two new antidepressants.