The US Food and Drug Administration has signalled that it is willing to move in the direction of shorter trials to license drugs for salvage therapy, following the lead of the European drug regulatory agency, the EMEA. However, significant differences in emphasis still exist between the European approach and the emerging consensus in the US.
Earlier this year a group appointed by the EMEA's scientific committee recommended that approval should be granted for drugs proven effective after 12 to 16 weeks in treatment-experienced patients - before 48 week studies are completed in treatment naïve patients. But the committee also emphasised that phenotypic and genotypic data would be necessary, and that provisional licenses would last for one year, renewable on the basis of safety data submitted.
The European guidelines were partly influenced by strong lobbying from the European AIDS Treatment Group, which has been recommending that the EMEA needs to take a pan-European view of the substantial differences in compassionate access to new antiretrovirals between European countries. While France, Germany and the UK have regulations which allow early access, Spain, Italy and Portugal do not have similar mechanisms.
Last week, a public hearing called by the FDA's Antiviral Advisory Committee heard that the FDA may prefer future license applications to consist of studies in treatment naïve and highly treatment-experienced patients, suggesting that studies testing an agent in people still naïve to one class of drug will not be considered adequate evidence of effectiveness in highly treatment-experienced patients.
However, the FDA gave no hint that it is willing to uncouple the licensing timelines for the use of drugs in naïve and highly treatment experienced patients, which means that companies could obtain licenses more quickly in Europe for salvage products. They may also be forced to design different types of studies if Europe and the US do not agree on their requirements.
A full report on the FDA hearing, written by Mark Mascolini, is available at the NATAP website.