Sphere No.46 (Mar 2019)

Sphere #46 2019 14 CHi-MED GOES GLOBAl >> in one type of cell tissue may also be found in another cell type in another part of the body. So a drug that works for one cancer may also help stall another. But usually, multiple processes are in play to help a tumour grow. The best approach to knock a tumour off its growth track is often to attack it on a number of fronts. For example, using drugs that block signals telling cells to split and other medicines that inhibit the growth of blood vessels that feed tumours with needed oxygen and nutrients. However, all these drugs often impact more than one biochemical pathway. They appear as what laymen call ‘side effects’ of treatment and the ‘toxicity’ of the drug. Think about people’s gums bleeding and hair falling out during treatment. Cancer drugs attack fast-growing cells, often including gums and hair follicles. Finding and developing drugs that precisely target the biochemical pathways you want to hit is crucial. The term for this is ‘selectivity’ and it means drugs that cause fewer side effects and have greater efficacy in stopping the tumour from expanding. ‘Clean’ drugs are those with high selectivity, which don’t create a host of side effects on the way to a cure. It is a single-minded obsession within Chi-Med, to choose and develop the cleanest, most selective drugs possible. Developers of single drugs as well as those developing drug combinations both strive for selectivity. Fruquintinib is a superior performer in this area (“super clean”, says Mr Hogg) and this may indicate that it can be used in treating other cancers in conjunction with drugs that might inhibit blood vessel growth or help the body’s own immune system to recognise the aberration and attack it. Research in this area has already begun and shows some promise. Again, it is not without setbacks, and the peculiarities of clinical trial targets and the pipelines of other firms complicate the competitive landscape. “The need for speed” is a key factor in drug development in order to get the medicines to market, as it is “very easy to be obsoleted,” explains Mr Hogg. For now, however, Elunate® is on the market, being prescribed and saving lives Blood vessel Tumour growth Tumours secrete several kinds of protein to promote blood vessels needed to provide blood flow to bring oxygen and nutrients to the tumour. Elunate® stops a crucial step in this process thus inhibiting tumour growth. Over a five-year period, Chi-Med signed agreements with companies including Merck, Johnson & Johnson and AstraZeneca.