GlaxoSmithKline has signed worldwide strategic alliance with Santaris Pharma that could be worth more then $700 million for the discovery, development and commercialisation of novel medicines against viral diseases.

Santaris Pharma will receive an upfront fee for the first antiviral programme of $3m (£1.5m) and GSK will make an equity investment of US $5m (£2.5m) in Santaris Pharma. If candidate drugs from the first viral target programme are successful and reach the market, GSK could make additional milestone payments to Santaris Pharma of up to $140m (£69.5m) for this first programme. Similar upfront payments and milestones are payable by GSK to Santaris Pharma in respect of each of the further three antiviral programmes if GSK elects to initiate these additional programmes in the collaboration.

In addition, if GSK exercises its option to further develop and commercialise SPC3649, it will make a further up front payment of $5m (£2.5m) and additional milestones of up to $122m (£60.5m) if the drug obtains regulatory approvals in Europe and the USA. Overall, under the collaboration Santaris Pharma could be eligible to receive in excess of $700m (£347m) in upfront fees and development and regulatory milestones payments. If a product is successfully commercialised, Santaris Pharma will receive high single to double-digit royalties on worldwide sales of alliance products.

GlaxoSmithKline will participate in the alliance through its Infectious Diseases Centre of Excellence for Drug Discovery (ID CEDD). Under the terms of the agreement, Santaris Pharma will grant GSK options to drug candidates discovered and developed under the collaboration in up to four different viral disease programmes. In each of these R&D programmes, Santaris Pharma will be responsible for the discovery and development of RNA antagonist drug candidates through to completion of phase IIa ("Clinical Proof of Concept"), at which point GSK has an exclusive option to license each compound for further development and commercialisation on a worldwide basis. GSK also has an option to include as an additional programme in the collaboration, SPC3649, Santaris Pharma's preclinical LNA-antimiR against micro RNA-122, which is being developed by Santaris Pharma as a potential new therapy for Hepatitis C infection.