Appointment of Non-Executive Chair

Appointment of Dr. Annalisa Jenkins, MBBS, FRCP as Non-Executive Chair

16th 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, today announced the appointment of Dr. Annalisa Jenkins, MBBS, FRCP, CEO of Dimension Therapeutics, Inc. (NASDAQ:DMTX), as Chair of Silence's Board of Directors. Her appointment as Non-Executive Chair is effective 16th October, 2017, on which date Dr. Stephen Parker, the Company's Non-Executive Chairman since September 2015 will become a Non-Executive Director.

A biopharma thought leader, Dr. Jenkins brings over 25 years of global industry experience to Silence's Board with a wealth of knowledge in advancing programs from scientific research through clinical development, regulatory approval and into healthcare systems globally. Prior to Dimension, Dr. Jenkins held multiple leadership positions, including executive vice president, head of Global Research and Development for Merck Serono. She led Global Medical Affairs and Quality and was a member of Merck Serono's Pharmaceutical Executive Committee. Previously, Dr. Jenkins had a nearly 15-year successful career at Bristol-Myers Squibb (BMS), attaining the role of senior vice president and head of Global Medical Affairs. During her tenure at BMS, Dr. Jenkins played a key role in the development, approval, and/or commercialization of products in multiple therapeutic areas, including immuno-oncology, cardiology, immunology and infectious diseases. She began her career as a medical officer with the British Royal Navy during the Gulf conflict, rising to the rank of Surgeon Lieutenant Commander. Dr. Jenkins graduated in medicine from St. Bartholomew's Hospital, London, and trained in cardiovascular medicine in the UK National Health Service.

In addition to the current and past Directorships listed below, Dr. Jenkins is also a committee member of the Science Board to the FDA, serves on the advisory board of the Center for Talent Innovation (U.K.) and is on the Advisory Panel of the Healthcare Businesswomen's Association.

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

"Annalisa's appointment is a significant moment in the transition of Silence to a fully-integrated biopharma company. Her extensive and broad experience in all aspects of biotechnology, drug development and commercialization will prove to be invaluable. It is a testament to the progress made at Silence that we have been able to attract Annalisa to our Board. Her appointment is a signal of our continued belief that 2017 will be remembered as "the year of RNAi.""

"At the same time, I would like to thank Dr. Stephen Parker for his two-year tenure as Chairman. At a very difficult time for the company and for myself personally, Steve has been instrumental in steering the company to the position that it is in today. We are delighted that Steve will remain on the Board as an important member of the team."

Dr. Annalisa Jenkins commented:

"Given the recent advances in delivery and chemistry in the RNAi field, I am now of the belief that gene silencing will be a major new drug modality. I believe that Silence's technology and IP represent a significant opportunity in the next generation of drugs that will potentially transform the treatment of serious diseases with significant unmet medical need, specifically where the liver is the primary target organ. These disorders often have devastating outcomes for patients and their families, and I look forward to contributing to the Company's advancement of these promising product candidates towards the clinic."

The following information is disclosed pursuant to Schedule Two, paragraph (g) of the AIM Rules for Companies:

Full name and age: Dr. Annalisa Mary Jenkins (aged 52).

Dr. Jenkins does not currently hold any ordinary shares in Silence Therapeutics.

Current Directorships or Partnerships:

Annalisa Jenkins LLC

Ardelyx, Inc.

Cocoon Biotech Inc.

Dimension Therapeutics, Inc.

iOX Therapeutics Limited

MedCity Limited

OncoSec Medical Incorporated

The Olivia Rose Fund

Thrombolytic Science, LLC

Vium, Inc.

YouBelong

Previous Directorships or Partnerships:

Ares Trading SA

Biothera Pharmaceuticals, Inc.

Prosensa Holding N.V.

TransCelerate BioPharma Inc.

Viventia Bio, Inc.

No further information in connection with her appointment is required to be disclosed under Schedule Two, paragraph (g) of the Aim Rules for Companies.

Enquiries:

Notes to Editors

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.