Three abstracts accepted for ATS Meeting

Mereo BioPharma Group plc

("Mereo" or the "Company" or the "Group")

Three abstracts accepted for American Thoracic Society Meeting, 19-24 May 2017

London, 23 January 2017 - Mereo BioPharma Group plc (AIM: MPH), a clinical stage, UK-based, biopharmaceutical company focused on rare and specialty diseases, is pleased to announce that, all three of the Company's submitted abstracts have been accepted for presentation as posters at the American Thoracic Society meeting in Washington, 19-24 May 2017.

The abstracts submitted relate to Mereo's clinical research with acumapimod (BCT-197), an orally active p38 MAP kinase inhibitor being developed as first-line acute therapy when added to standard of care for patients with an Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD).

Alastair MacKinnon, Mereo's Chief Medical Officer, commented: "We are extremely pleased to announce that all three of our submissions have been accepted for the high profile American Thoracic Society meeting in Washington. We are delighted that they have all been accepted and that the high quality of the research is being recognised by the American Thoracic Society. We look forward to attending the conference in May."

More information on the abstracts will be available in due course.

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About Mereo

Mereo is a UK-based biopharmaceutical company focused on the development of innovative medicines that aim to address unmet medical needs in rare and specialty disease areas and improve patient quality of life. The Company seeks to selectively acquire development-stage product candidates with demonstrated clinically meaningful data from large pharmaceutical companies and to rapidly progress these product candidates to subsequent value inflection points.

Mereo combines the operational discipline and efficiency of a small company with the financial resources to conduct comprehensive clinical studies. The Company has the option to directly commercialise products, for example in orphan diseases, in addition to partnering or divesting its products.

Mereo's initial portfolio consists of three mid-late stage clinical assets that were acquired from Novartis in July 2015. BPS-804 is being developed for the prevention of fractures resulting from osteogenesis imperfecta (brittle bone disease); acumapimod (BCT-197), is being developed to treat inflammation in patients with an AECOPD; and BGS-649 is a once-weekly pill to restore normal testosterone levels in men with hypogonadotropic hypogonadism.

In H1 2016 the Company initiated a Phase 2 study with acumapimod and a Phase 2b study with BGS-649. Mereo expects to commence the first pivotal trial for BPS-804 during H1 2017. Additional product opportunities, from a range of large pharmaceutical and biotechnology companies, are under active evaluation.

About acumapimod

Acumapimod is an orally active p38 MAP kinase inhibitor being developed as first-line acute therapy when added to standard of care for AECOPD patients. The ongoing Phase 2 study is planned to enroll 270 patients in the US and EU and is designed to study different dosing regimes of acumapimod on top of standard of care in patients presenting with an AECOPD in the hospital setting. The primary end point is lung capacity, as measured by FEV1, with a range of exploratory secondary end points including hospital stay times, patient reported outcomes and re-exacerbation rates during a six month follow-up period.

About AECOPD

An AECOPD is characterised by a sudden worsening in the COPD patient's symptoms of dyspnoea, cough and sputum production. Acute exacerbations last for several days and require a step up of medication and often hospitalisation. AECOPDs occur in the natural course of the disease and are commonly triggered by infections and air pollution, however one third do not have an identifiable trigger. Both airway and systemic inflammation are characteristic drivers of the disease.