Schering AG and UK giant AstraZeneca have hooked up to develop the German firm’s investigational breast cancer drug – a selective oestrogen receptor downregulator (SERD) that the companies hope will offer a new means of treating the disease.

SERDs work in a novel way to target the hormone oestrogen, high levels of which are related to the development and progression of breast cancer. Although there are a number of anti-hormonal therapies on the market, many tumours eventually become resistant, so there is still a need for newer, more effective compounds. SERDs’ mechanism of action is to downgrade the protein responsible for the manufacture of oestrogen receptors, thereby reducing the number of receptors able to interact along the signalling pathways responsible for tumour growth and progression.

Although no financial details of the agreement were unveiled, AstraZeneca – whose pedigree is in breast cancer research and development – will lead clinical investigations of the preclinical compound. Meanwhile, Schering will take the principal role in non-clinical activities and manufacturing and, if it makes it through the clinic onto the market, the SERD will be promoted in major territories by both Schering and AstraZeneca.