US Pharm. 2008;33(10):8.

The research and development (R&D) process for a new drug takes an average of 10 to 15 years and involves many discrete steps and activities. This process accounted for a developmental cost of $1,318 million in 2006. According to the Pharmaceutical Research and Manufacturers of America (PhRMA), the cost to develop a biologic in 2006 was estimated to be $1.2 billion. There have been fewer new approvals in recent years, despite increased investment in R&D.

The Approval Process
If the clinical-trial results demonstrate that the benefits of the drug outweigh its risks, the sponsor files a new drug application (NDA) with the FDA to request approval to market the drug. The review process for NDAs is extremely lengthy, involving all clinical and preclinical findings, the proposed labeling, and the manufacturing plans. The FDA reviews all of the information in the NDA to determine whether the candidate drug is safe and effective enough to be approved for use in patients. The standard FDA review process is adopted when a drug appears to have therapeutic qualities similar to those of a drug already on the market. An NDA is subject to the FDA's priority review when a drug appears to represent an advance over existing therapy. The agency can approve the drug, request more testing, or deny approval.

From 2000 through June 2008, a total of 77% of all original NDAs approved (i.e., 80 NDAs per year) underwent the standard FDA review process. Sixteen percent of all original NDAs approved (i.e., 17 per year) were subjected to priority review by the FDA. During the same period, 7.3% of all NDAs approved (i.e., eight per year) were designated as having orphan drug status. In 2001, the FDA approved 55 NDAs, the smallest number of approvals in any calendar year, while in 2004 it approved 158 NDAs, the greatest number of approvals in any calendar year. Irrespective of year, in the month of December, the FDA approved the greatest number of NDAs, while the smallest number of NDAs was approved in the month of February. Among all NDAs approved, the tablet dosage form had the highest prevalence, followed by injection and capsule forms.

Postreview Developments
An increasing number of new compounds and therapeutic proteins are moving into clinical testing following FDA review. According to the PhRMA, more than 2,700 drugs currently are in clinical trials or are undergoing FDA review for 4,600 indications. Among the projects in progress are 596 drugs in late-stage development for cancer, 71 for HIV/AIDS, 60 for diabetes, 73 for arthritis, and 57 for Alzheimer's disease.

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