July 23, 2006

Drug trial dosing caution urged after UK disaster

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

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

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.