THERE is fresh evidence of a dwindling number of new drugs coming on to the market from the pharmaceuticals industry as a new research shows that just seven per cent of sales come from medicines launched in the past five years.

The report by CMR International, owned by Thomson Reuters, shows the bulk of sales at the world's leading pharmaceuticals is derived from an ageing portfolio of drugs, while the number of medicines failing during late-stage testing is sharply on the rise.

The problem is the 'patent cliff' — after a few years products lose the protection of the patent and generic drugmakers are allowed to produce cheaper versions.

Christopher Sampson, a spokesman for AstraZeneca, conceded that there had been “a bit of a dip in the number of products in recent years across the industry”, with new drugs not as big as existing blockbusters such as Pfizer's cholesterol medicine Lipitor, the largest-selling drug in the world. The percentage of revenue from new drugs fell from eight per cent a year ago.

“What you are seeing is a bit of a crisis,” said Jane Sharples, general manager of CMR. “The science is getting tougher. A lot of the easy medicine has been done,” she said. As a result, many drugmakers resort to launching 'me too' products that are similar to ones already on the market.

A decline in success rates for new drugs has taken its toll on productivity, as indicated by a doubling in the number of products scrapped after reaching the final stage of drug development between 2007 and 2009, compared with 2004-06.

“Late-stage drugs failing is clearly the crux of the problem for the industry,” said Sampson. In recognition of this, pharmaceutical groups are buying in new medicines from smaller firms and teaming up with competitors and academic organisations to develop new treatments.

AstraZeneca, the UK's second-largest drugmaker, has a joint venture with Bristol-Myers Squibb for two new diabetes drugs.

— The Guardian, London