Silence takes Alnylam to court over RNAi IP dispute

The Royal Courts of Justice, where the High Court is based. (Courtesy of sjiong [CC BY-SA 2.0])

Silence Therapeutics has asked the United Kingdom High Courts of Justice to rule on an intellectual property dispute with Alnylam and The Medicines Company. The British biotech wants to know whether it is entitled to intellectual property rights on some of the companies’ late-phase assets.

Specifically, Silence has asked the court to determine whether it is entitled to supplementary protection certificates (SPCs) on Alnylam’s patisiran, fitusiran, givosiran and inclisiran, the latter of which is partnered with The Medicines Company. SPCs give the holder up to five years of European market exclusivity after the general patent expires.

The drugs singled out by Silence are the most advanced assets in Alnylam’s pipeline. Hereditary ATTR amyloidosis candidate patisiran is closing in on phase 3 data and the others are following close behind. As Silence sees the situation, its patents entitle it to a slice of any success the drugs achieve. 

The court filing follows two months of sword-rattling by Silence. In two statements released in May, the company talked up its IP and stated its belief that other biotechs’ late-phase drugs are infringing on its patent estate. Silence shied away from naming the alleged infringers. But by reeling off a list of diseases and stating its IP covered RNAi, it pointed its finger at Alnylam.

Back then, Silence said it was open to granting licenses to its IP, as it did to Quark Pharmaceuticals in 2005. Silence’s relationship with Quark subsequently soured. Quark’s CEO accused Silence of “deceiving the public” and the companies had a now-resolved disagreement about a milestone payment. But Silence still referred back to the Quark deal when discussing how much it could squeeze out of Alnylam.

The reference noted that while the Quark deal covered preclinical programs, the Alnylam assets are already in late-phase trials. That underpins Silence’s belief its latest IP infringement pursuit can have a “significant financial effect” relative to its market cap, which is currently £67 million ($87 million).

Silence is also working on patent cases in other parts of the world.