July 24, 2006
Drug Trial Dosing Caution Urged
By Ben Hirschler
LONDON (Reuters) - Greater caution is needed in early stage tests of novel drugs that stimulate the immune system and only one patient should be given active medicine on the first day, a joint industry taskforce said on Monday.Six men were left seriously ill when a clinical trial in Britain using an experimental drug went badly wrong in March, triggering widespread public alarm and sending shockwaves through the pharmaceuticals industry.
All six healthy volunteers were given the drug, made by German biotech firm TeGenero AG, at the same time.
Colin Dollery, a consultant to GlaxoSmithKline who co-chaired the taskforce, said tens of thousands of initial Phase I trials were conducted without incident but the TeGenero episode highlighted the need for extra care with potent biotech drugs.
This was particularly the case when drugs activated biological processes in the body rather than inhibited them.
British regulators earlier this year concluded that TeGenero's drug TGN 1412 appeared to cause an unprecedented biological reaction in humans by stimulating the immune system, a reaction which was not seen in animals.
"The great majority of drugs are antagonists -- in other words, they inhibit processes," Dollery told Reuters.
"Only a minority are agonists, which activate a process. If you have a biological drug that is intended to activate the immune system, which TGN 1412 was, then you have to be very much more careful."
Other recommendations from the taskforce, which was set up by the Association of the British Pharmaceutical Industry and BioIndustry Association, included improvements in ascertaining the right starting dose, and "staggered dosing" as levels were increased.
Privately owned TeGenero filed for insolvency earlier this month as the publicity surrounding the disastrous Phase I study made it impossible for the company to attract investment to keep operating.
The trial of TGN 1412, which was designed to treat chronic inflammatory conditions and leukemia, was conducted on behalf of TeGenero by contract research firm Parexel at Northwick Park Hospital in northwest London.
The joint industry taskforce has submitted its conclusions to a separate, government-appointed expert committee on first-in-human clinical studies under Professor Gordon Duff, which is due to issue its report later on Monday.