New or modified indication approvals by the US Food and Drug Administration for existing prescription drugs have been increasing steadily since the late 1990s, according to new research released this week.
The number of new or modified indication approvals - eg, consent by the FDA to market drugs for indications other than the original, based on additional clinical studies - increased 17% from 1998-2003 to 2004-09, says an analysis published by the Tufts Centre for the Study of Drug Development (Tufts CSDD).
Faced with patent expires on many of their products over the next few years, plus stagnant growth in new approvals both in the US and worldwide, drug developers are now looking for new sources of revenue, and supplemental approvals for existing products may be one such source, says the report.
However, while approvals for new indications can translate into revenue growth, exactly how much can be gained will depend on the use and the number of competitor products; therefore, levels of growth can vary widely, comments Joseph DiMasi, director of economic analysis at Tufts CSDD and author of the study.
"Many companies are working to find the right balance between investing R&D resources and finding new indications for existing drugs and developing novel compounds," he adds.
The study, which is reported in Tufts CSDD's latest Impact Report, also found that, among drugs which were originally approved during 1963-2009, the number of new or modified indications per product ranged from one to as many as 20 during 1998-2009. The main driver of such approvals during the latter period was paediatric indications, which increased 107% from 1998-03 to 2004-09, while anti-infectives and drugs for the central nervous system each accounted for at least one-fifth of all new or modified indications approved by the FDA from 1998 to 2009.
Moreover, the mean regulatory approval phase time for new or modified indications fell from 13.6 months during 1998-02 to 10.8 months in 2004-09, a decline of 21%, the analysis notes.