SR Pharma plc, Europe's leading RNAi therapeutics company, announces that the European Patent Office has granted the company its core RNAi patent EP 03784183.0.

This patent covers its novel, stabilised, small interfering RNA (siRNA) molecules with blunt ends and positional modifications. These proprietary siRNA molecules are referred to as 'AtuRNAi' by SR Pharma.

This is the first patent to be granted for this new class of stable siRNA molecules and provides SR Pharma with freedom to operate within the RNAi therapeutics field. The 38 claims in the patent cover AtuRNAi structures that have a well defined positional arrangement of modified nucleotides. These novel siRNA molecules developed by SR Pharma have important advantages over conventional siRNA molecules including increased stability against nuclease degradation and an increased serum half life, a SR Pharma press release stated.

These AtuRNAi compounds form the basis of SR Pharma's own therapeutic development pipeline which is focused on cancer indications. The Company's first clinical trials in the cancer field are expected to start in 2007. These molecules also form the basis of the group's licence and collaboration agreement with Quark Biotech Inc. and the recently announced sublicense to Pfizer Inc., whose Phase I clinical trial in Age-related Macular Degeneration using these molecules is expected to start in the near future.

Dr Klaus Giese, chief scientific officer of SR Pharma said "This patent is a major step forward for SR Pharma. The broad coverage that we have gained for our novel AtuRNAi molecules reflects our significant understanding of RNAi chemistry. We are confident that we will be able to gain a similar level of patent protection for our AtuRNAi molecules from the US patent office during the course of 2007."

Iain Ross, chairman of SR Pharma, said: "This patent provides us with the freedom to operate within this exciting area of science and validates our unique technology approach. It also puts us in a much stronger position to conclude licensing and corporate development deals which we expect to play a crucial role in our goal to become a global leader in the development of RNAi therapeutics."

SR Pharma plc is a European biopharmaceutical company, listed on AIM. The Company has two operating subsidiaries Atugen AG based in Berlin, Germany and Stanford Rook Ltd based in London, UK. SR Pharma is a leader in RNAi therapeutics, which is a Nobel Prize winning technology that "silences" genes linked to the onset of disease.