Magnets for cancer therapy
Magnets and magnetic fields have long been ascribed healing properties by alternative medicine practitioners, but until now the use of magnetism in modern medicine has been mainly for diagnostic purposes.
This could be about to change, with the arrival of cancer-seeking nanoparticles - primed to wipe out tumours thanks to their magnetic properties.
The novel particles are being developed through collaboration between the University of Durham, Celltech Antibody Centre of Excellence, part of UCB, and Oxford Instruments Molecular Biotools. Using science that has never previously been applied in pharmaceuticals, Celltech’s targeted antibody technology will deliver inert nanoparticles to tumours, which will then be treated using controlled external magnetic fields, says Mike Eaton, Celltech’s head of antibody chemistry.
Unlike many current anti-cancer drugs, Celltech’s pioneering targeted therapies avoid damage to healthy tissue. The company’s earlier collaboration with Wyeth produced Mylotarg, the first antibody targeted chemotherapy medicine, in 2000. While Mylotarg has brought in only modest revenues due to the size of the market, acute myeloid leukaemia, the technology has been the launch pad for research into targeted therapies worldwide.
According to Eaton, the new magnetotherapy will be administered in very small doses, similar to Mylotarg, in which the toxin is injected in just two sub-milligram doses to complete the course of treatment. ’Getting the tumour dosage right will be crucial,’ he explains.
Celltech has also created technology to make ultra-potent antibodies rapidly - a technique that will be used by the new partnership. The antibodies find their target using cell-surface markers found on tumours.
’The antibodies then accumulate on the tumour and we wait for background levels to clear,’ says Eaton. ’Then we will activate the therapy externally.’
Experts in fabricating designer magnetic particles - an interdisciplinary team from the University of Durham led by John Evans, reader in inorganic chemistry - will work initially to make and coat the magnetic particles. Physicists at the university will create the magnetic nanoparticles, which chemists will then coat with the antibody.
The antibodies and nanoparticles are chemically bonded, although the exact details remain a trade secret: ’The issue is biocompatibility,’ says Eaton. ’These particles are being designed specifically for this project and prototypes have already been made.’
The controlled magnetic environment that will trigger the death of the targeted tumour cells is the realm of the Oxford Instruments Molecular Biotools team, led by Andy Sowerby. The team is currently evaluating the required magnetic field to devise a prototype design for a unique magnetic device for the new therapy.
The collaboration is projected to run for at least three years, and is currently funded by Celltech and Oxford Instruments Molecular Biotools. Celltech scientists will be involved in in vitro studies and in pharmacological studies later on, and will make full use the company’s oncology expertise. They hope to target a range of tumours such as those found in breast, colorectal or lung cancer.
’We have managed to assemble the best team to drive this ground-breaking, nanosurgery project right from its earliest stages,’ Eaton said. ’We have signed a three-way agreement involving the UK leaders in antibody technology, magnetic instruments and nanoparticle design in our quest to explore new opportunities in cancer treatments. In five years, all being well, we could be at the clinical trials stage.’
The product could reach the market in around 10 years’ time.
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