John Jenkins, head of the Food and Drug Administration´s (FDA) Office of New Drugs, stated the agency is behind in approval of new applications because of the lack of staff to comply with an added workload imposed by Congress.

The U.S. regulators failed to meet their own timetables for decisions on at least 15 drugs so far this year, according to data compiled by Corey Davis, an analyst with Natixis Bleichroeder in New York.

The FDA sets non-binding timelines for action on new medicines under the Prescription Drug User Fee Act, known as PDUFA, the law under which pharmaceutical companies help pay the agency to handle their applications.

Missing the dates leaves companies and investors “hanging,'' and “ambiguity breeds weakness'' in drugmakers' stock prices, Davis said.

Drug-safety legislation approved by Congress last year gave the FDA new responsibilities, adding to the workload of a staff that was already too small to keep up, Jenkins said. Congress gave the FDA added power to impose restrictions on the sale of drugs and to require that studies be completed after products are on the market.

Prasugrel, a blood thinner from Eli Lilly & Co and Daiichi Sankyo Co, and Schering-Plough Corp´s asenapine for schizophrenia are among the medicines delayed. Also Promacta, a bleeding-disorder drug from GlaxoSmithKline and Ligand Pharmaceuticals Inc; and the diabetes drug alogliptin, fromTakeda Pharmaceutical Co, who said the FDA didn't complete its review of alogliptin as expected by October 27 “due to internal resource constraints.''

The agency's goal is to review and act within 10 months on 90 percent of standard new drug applications and within 6 months on priority applications for drugs that offer major advances or provide a treatment where no adequate therapy is available.

Increases in user fees paid by drugmakers, and other funding, have allowed the FDA to hire more. The agency's Office of New Drugs hired about 200 people in the fiscal year ended in September and expects to soon reach 890 full-time employees, said FDA spokeswoman Rita Chappelle.

Once the new employees are in place and trained, the number of missed deadlines should decrease, Jenkins said.

There are opposing reactions to news on FDA delays.

On the one hand, the Pharmaceutical Research and Manufacturers of America say they are understanding, and hope for a quick resolution, and National Health Council assistant vice president for government affairs and programs Kevin Cain said missed dates are not good for patients because it slows drugs in the pipeline.

On the other, groups that are critical of the FDA's drug safety record have complained in recent years that the agency rushes to meet its goals for approving new medications even when there are potentially dangerous side effects. Head of Public Citizen´s Health Research Group said taking more time is a “good development.”

Wolfe considered that a PDUFA deadline game forces medical officers to conclusions “they might not fully agree with.”

The tally of missed action dates doesn't include cases where the FDA formally extended review times or issued so-called complete-response letters. The letters inform drugmakers of reasons a product didn't win approval, often requesting further data or additional studies.