New divisional patent and injunction application

Silence Therapeutics Announces Receipt of a New European Notice of Intention to Grant a Patent and the Launch of an Interim European Injunction Application against Onpattro™

October 10 2018

LONDON, Silence Therapeutics plc, (LON:SLN) ("Silence" or "the Company") a leader in the discovery, development and delivery of novel RNA therapeutics for the treatment of serious diseases, confirms the receipt of a notice of intention to grant for a new European divisional patent, EP 3 222 724B, and further said that it has commenced a new cross-border interim injunction application in the Netherlands against Alnylam's Onpattro™ (patisiran).

Silence received a notice of intention to grant from the European Patent Office for patent application EP 3 222 724B, further strengthening its innovative chemical modification technology patent family in Europe, which sits at the heart of the current therapeutic siRNA field.

Silence has further filed a cross-border interim injunction application in the Netherlands (where Alnylam holds its Marketing Authorisation for Onpattro™), requesting the courts to prohibit Alnylam from commercialising Onpattro™ across Europe until the resolution of the trial to determine infringement of EP 3 222 724B by Onpattro™. Despite requests not to do so, Alnylam has openly commercialised Onpattro™ in the face of the Silence claims. The Company therefore feels that it has been left with no alternative other than to take the necessary steps to enforce its patents and protect the historic investment made in its technology.

Onpattro™ remains accused of infringement of Silence European Patent EP 1 847 547B in the United Kingdom and Portugal and Silence is seeking injunctive relief in these territories to restrain Alnylam's infringement. The UK trial is to be held in December 2018, with a decision expected in early 2019. While Silence continues to protect its rights and inventions, the Company remains focused on executing its core business of drug discovery and development to continue to build its therapeutic pipeline.

David Horn Solomon, Chief Executive Officer of Silence Therapeutics, commented:

"Silence continues to innovate with new, competitive RNAi medicines. During 2017 & 2018, the European Patent Office has upheld the validity of our expanding patent estate with the granting of additional patents around our foundational chemical modification IP. 

When companies openly promote new product commercialisation in the face of relevant granted patent rights, Silence Therapeutics will take steps to enforce its patents and protect the historic investment made in its technology." 

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About Silence Therapeutics plc

Silence Therapeutics is developing a new generation of medicines by harnessing the body's natural

mechanism of RNA interference, or RNAi, within its cells. Its proprietary technology can selectively

inhibit any gene in the genome, specifically silencing the production of disease-causing proteins. Using

its enabling delivery systems, it has achieved an additional level of specificity by delivering its

therapeutic RNA molecules exclusively to target cells. Silence's proprietary RNA chemistries and

delivery systems are designed to improve the stability of our molecules and enhance effective delivery

to target cells, providing a powerful modular technology well suited to tackle life-threatening diseases.

For more information, please visit: https://www.silence-therapeutics.com/