Silence Therapeutics takes rival Alnylam to court in patent fight

DNA sequence

Silence Therapeutics has launched legal action alleging that late stage drugs from rivals Alnylam and The Medicines Company infringe its intellectual property.

Silence, which specialises in developing RNA-interference based technology that "silences" defective genes behind inherited diseases, issued the claim in the UK High Courts of Justice (Patents Court), naming US-based Alnylam, its UK affiliate and the Medicines Company UK as defendants.

The claim asks the court to determine whether Silence is entitled to European patent protection on several late-stage Alnylam products, including one developed in partnership with The Medicines Company.

Silence is asking whether it is entitled to “supplementary protection certificates”, which can give up to five years of exclusivity after a patent expires.

Litigation such as this is quite common in pharma, and are often settled by granting a licence to the claimant.

The royalty received as a result of the licence depends on how far the drug has gone down the clinical development process.

Licences on preclinical assets pay out single-digit percentages, but the royalty received on late-stage assets such as Alnylam’s can be considerably higher.

The claim includes the late stage drugs patisiran, being developed for hereditary ATTR amyloidosis, fitusiran for haemophilia and rare bleeding disorders, and inclisiran for hypercholesterolaemia, developed in partnership with The Medicines Company.

It also relates to the early stage givosiran for acute hepatic porphyrias, Silence Therapeutics said.

There is no suggestion that Alnylam and The Medicines Company acquired intellectual property through any transfer of secrets.

Instead pharmaphorum understands that the case is focused on publicly available information about Alnylam’s treatments, which are considerably further advanced along the pipeline than Silence’s.

Silence flagged its legal action at the end of May, when it said it had 'expanded and strengthened' its patent estate.

Ali Mortazavi, chief executive of Silence Therapeutics, commented at the time:

"We continue to believe that several third party late-stage clinical RNAi candidates, including lipid nanoparticle and GalNAc based products, require licences under our patent portfolio, and have therefore written to one company to this effect.  Silence is committed to defending and securing the appropriate value for our IP and is exploring alternative ways to leverage this asset.  

He added: "The first launch for these medicines is anticipated in 2018.  We consider that potential licences under our patent estate could have a significant financial effect relative to the current market capitalisation of Silence."

An Alnylam spokesperson said: “We firmly believe we do not infringe any valid patent claims and will vigorously defend against any legal action by Silence."

No-one from The Medicines Company was immediately available for comment.