FDA approvals of NMEs lag.

Through Oct. 31, FDA had approved just 15 drugs classified as "new molecular entities," a pace at which the agency would green-light just 18 new drugs (not counting vaccines or additional uses for existing drugs) by year-end, Dow Jones Newswires reported.

By comparison, FDA approved 22 NMEs last year, 20 in 2005 and 36 in 2004.

Some companies pin the blame on a skittish FDA. Safety worries since Merck withdrew painkiller Vioxx three years ago have put a chill on the agency, they say. FDA concerns have delayed several expected blockbusters, including Novartis's diabetes drug Galvus and Sanofi-Aventis's diet drug Acomplia (rimonabant.)

Companies say FDA is hunkering down against criticism. "It just indicates to you that when bureaucrats come under pressure, they tend to choose the path of asking for more data, as opposed to approving the drug," Schering-Plough's CEO Fred Hassan said in an interview with DowJones.

If an experimental drug treats a condition for which there are already options for treatment, FDA seems to have raised the bar significantly, the industry says. Wyeth, for instance, has seen delays for approval Pristiq, a treatment for depression and menopausal symptoms. Treatments for both conditions abound, including some sold by Wyeth itself. "In categories where there are choices, the agency is making more demands for approval," Joseph Mahady, a Wyeth executive said. "It's across the board. Everybody's got to adjust to that."

FDA argues that its criteria for review haven't stiffened substantially. "There have been no systematic changes in how FDA is approaching the approval standards for new drug applications," a spokeswoman told the news services. "Each application is reviewed on its own merit and judgments are made by the signatory authority as to whether the application meets the statutory standards."

Several companies have seen novel medicines approved this year, including Merck's Isentress and Pfizer's Selzentry for HIV/AIDS, as well as three cancer treatments: Wyeth's Torisel, GlaxoSmithKline's Tykerb and Novartis's Tasigna.