In today's industry, the rate at which new drugs are approved can give good insight as to the research and development (R&D) sector's overall health, as well as highlighting areas held back by risk-averse authorities or too much 'red tape' bureaucracy.
Over recent years, the new drug approval rate in the US has been falling. And, according to new research, it has been happening at a quicker pace than previously thought.
A study released by the Biotechnology Industry Organization (BIO) in February 2011 revealed that the country's overall success rates are now almost as low as one in ten. This figure applies to new medicines moving through clinical trials to US approval between late 2003 and the end of 2010.
This compares to earlier – more optimistic – reports, which suggested that rates were around the one-in-five to one-in-six mark. But the BIO claims that its new findings build on the older analysis, using a "broader, deeper and larger sample" of clinical trials and approvals data. Researchers used the BioMedTracker (BMT) database of approximately "4,500 drugs and over 8,000 development paths".
Looking at figures collected across the past seven years, the BIO report notes that overall rates of approval by the US Food and Drug Administration (FDA) are roughly nine per cent. This applies to the success rates of medicines moving from Phase I to approval, comprising lead and secondary indications. Separating them out, lead indications achieve success at roughly one in seven and secondary at around one in 30.
The BIO scientists also found that large-molecule treatments were often twice as successful in being granted approval than smaller-molecule medicines.
"We believe that this study provides the market with an accurate and comprehensive picture of the relative difficulty of achieving product approval in the US," Michael Hay, senior biotechnology analyst at BMT, told the Pharma Times.
He went on to say that "strikingly, oncology drugs have the toughest time making their way through the clinic, despite cancer being the most closely studied area in drug development".
But what makes the US pharmaceutical market so "difficult'? Are approval rates falling as a result of declining R&D productivity? Or is it more to do with changes to the processing of applications?
There are significant volumes of peer-reviewed literature on this topic and one piece in particular stands out for its depth and meaning. Published last year, a report by the Tufts Center for the Study of Drug Development examined trends in the rate of new drug approvals over the past three decades, with a specific focus on the years between 2000 and 2009.
The analysts found that US drug approvals had increased from the start of the 1980s to the mid-1990s, but had since dropped back to their former levels. However, the study's authors urged the industry not to be alarmed as the peak, they said, was likely to have been influenced by the introduction of the Prescription Drug Use Fee Act (PDUFA) in 1992. If they were right, this would indicate that the approval rate fluctuation was merely the result of a change in the processing of applications, rather than a drop in developers' productivity.
The PDUFA, which was brought in to allow the FDA to demand an application fee from drug makers to assist with speeding up the approval of new medicines, has in recent years effectively shortened the length of time usually required before the final acceptance phase. In fact, a process that had previously been taking, on average, almost three full years can now be done in roughly half that time.
For the most part, successful drug development appears to be more about striking upon specific methods that work for each and every individual product. This is a point recently made by Australian pharmaceuticals firm Clinuvel.
In a February blog posting, the company explained: "There is no precise formula for successful novel drug development, each molecule has its own pharmacological activity and addresses unique set of diseases.
"Indeed, the rate at which new drugs are approved suggests that each drug has its own formula for success, or that a combination of strategies is required to satisfy the regulatory requirements.
"In Clinuvel's case with, Scenesse (afamelanotide), we face our own specific development and regulatory challenges, but now that we have arrived at the final stages we try to learn from all cases around us how to optimise our chances of regulatory clearance in the first attempt."