AstraZeneca has extended its R&D collaboration with Silence Therapeutics which is focusing on the identification of small interfering RNA-based drugs.

Under the terms of the agreement, which was originally signed in July 2007 and “has progressed well since,” the two companies are developing five novel siRNA therapeutic molecules focused on respiratory diseases and cancer. The collaboration has been extended by a year.

As announced previously, in addition to the initial £7.5 million Silence received in July 2007, the collaboration may generate up to £200 million in fees and milestone payments, plus royalties. The UK biotech says its team “interacts closely with several of AstraZeneca's operational units”, including Medimmune in the USA and with researchers in Sweden, the UK and China.

The terms of this agreement are independent of Silence's siRNA delivery collaboration with AstraZeneca which was also extended in April this year. That pact is focused on developing methods of delivering siRNA drugs.

Thomas Eichholtz, vice president of respiratory and inflammation research at AstraZeneca, said the firm is committed to the development of new therapeutic technologies that have the potential to create novel therapies. He added that “we are very pleased with the progress we have made”, while Silence chief executive Philip Haworth said that “AstraZeneca is a strong endorsement of our technology and we are delighted to continue working together”.