Safety expert sounds biotech alarm
Sarah Boseley and Ian Sample
The Guardian, Thursday March 16, 2006
A leading drug safety expert warned yesterday that scientists should not take lightly the potential hazards of modern biotech drugs, such as the one that has endangered the lives of six volunteers.
Conventional drugs are simple chemicals, said Saad Shakir, head of the Drug Safety Research Unit at Southampton University. But modern biotech drugs, produced through genetic engineering, are effectively large proteins. Contamination during the manufacturing process, for instance by a virus, would be far easier - and the drugs also have more potential to cause a harmful reaction in the body.
"The message is that biological products are more complex products. They are a protein, so they can induce reactions in the body which could be of an allergic or hypersensitive nature," said Dr Shakir.
Phase-one studies carried out on healthy people to check the safety of new drugs had been very safe in the past, he said. "You could count the number of fatalities on the fingers of one or two hands." But now that a new generation of biological products had arrived, we could be into "a new paradigm".
At TeGenero, the 15-strong German biotech company that brought what it hoped was an exciting, innovative drug into its first human trials, scientists were still trying to absorb the shock yesterday and begin to help investigators at the Medicines and Healthcare Products Regulatory Authority in the UK. TeGenero insisted that nothing in the laboratory work and animal testing performed prior to the human trials would have warned it of the extreme reaction in the volunteers. "These events were completely unexpected and do not reflect the results we obtained from initial laboratory studies which enabled us to progress investigations into human volunteers," said Benedikte Hatz, its chief executive.
The new drug, known as TGN1412, was being developed "for the treatment of immunological diseases with a high unmet medical need, such as multiple sclerosis, rheumatoid arthritis and certain cancers", the company said.
The company that TeGenero contracted to run its clinical trials, US-based Parexel, expressed itself just as stunned as TeGenero and emphasised the speed with which its staff got medical help for the volunteers. "We worked in cooperation with the [Northwick Park] hospital intensive care doctors and the sponsor to have the volunteers given the best possible care, and to explore all possible treatment options," said Herman Scholtz, head of Parexel International Clinical Pharmacology.
Parexel recruits volunteers on the internet, where a site clearly aimed at students offers free meals, time to study, pool and internet access as well as more than £1,000 per trial, depending on its length.
How it should work
· TGN1412 uses artificial antibodies designed to target a subset of immune system cells called T cells.
· Rheumatoid arthritis is believed to be caused by some T cells attacking the body.
· The antibodies in the drug get into the bloodstream, seek out the immune cells and latch on to them.
· Most antibody treatments work by shutting down biological reactions, but this drug is designed to do the opposite. The antibodies should bind to the rogue immune cells so well that they over-stimulate them, making them burn out and die.
Go to a Print friendly Page
Email this Article to a Friend
Back to the Archive