Serving of claim in the UK High Court

Serving of claim in the UK High Court

17 October 2017

Silence Therapeutics plc, AIM:SLN ("Silence" or "the Company") a leader in the discovery, delivery, and development of novel RNA therapeutics for the treatment of serious diseases with unmet medical need, announces that it has today delivered to the defendants its claim for declaratory relief relating to its entitlement to Supplementary Protection Certificates (SPCs) on certain Alnylam products. This claim was issued in the UK High Court (Patents Court) naming as defendants Alnylam UK Limited, Alnylam Pharmaceuticals Inc, and The Medicines Company UK Limited.

Silence has previously stated that it is committed to defending its Intellectual Property (IP), and to secure the appropriate value for this IP it will act to enforce its patent estate as necessary. The serving of the claim on the defendants begins the next phase in the UK legal process. UK High Court claims such as this can take approximately one year to decide upon, with possible appeal timelines also to factor into the overall timeframe for dispute resolution, but timings can vary. The claim asks the Court to determine whether Silence is entitled to SPCs on several late stage Alnylam products, which include Patisiran, Fitusiran, Givosiran and Inclisiran (partnered with The Medicines Company), and could result in the extension of Silence's European patent protection on these products. SPCs are intellectual property rights which can give up to 5 years of exclusivity after a patent expires. Separately, Silence is actively continuing to uphold its patent estate in other global regions.

Ali Mortazavi, Chief Executive Officer of Silence Therapeutics, commented:

"We reiterate that we consider potential licences under our patent estate could have a significant financial effect relative to the current market capitalisation of Silence. As such, we consider the continuation of this process to be the next step in seeking to realise this value."

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About Silence Therapeutics plc

Silence Therapeutics develops a new generation of medicines by harnessing the body's natural mechanism of RNA interference, or RNAi, within its cells. Our proprietary technology can selectively inhibit any gene in the genome, specifically silencing the production of disease-causing proteins. Using our enabling delivery systems, we have achieved an additional level of specificity by delivering our 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.