Mereo BioPharma Group plc, a biopharmaceutical company, develops and commercializes therapeutics for the treatment of oncology and rare diseases in the United Kingdom, the United States, and internationally. It develops Etigilimab (MPH-313), an antibody T-cell immunoreceptor with Ig and ITIM domains, which is in Phase 1b clinical trial for the treatment of tumors. The company is also developing Navicixizumab (OMP-305B83), which has completed Phase 1b clinical trials for the treatment of the late line ovarian cancer; Acumapimod (BCT-197), a p38 MAP kinase inhibitor that is in Phase II clinical trials to treat acute exacerbations of chronic obstructive pulmonary disease; and Leflutrozole (BGS-649), an oral aromatase inhibitor for the treatment of hypogonadotropic hypogonadism which is in Phase 2 trials. In addition, it develops rare disease product candidates, including Setrusumab (BPS-804), an antibody for the treatment of osteogenesis imperfecta and Alvelestat (MPH-966), an oral small molecule that is in Phase II clinical trial to treat Alpha-1 anti-trypsin deficiency. The company has a license agreement with Feng Biosciences for the development and commercialization of navicixizumab; license agreement with ReproNovo for the development and commercialization of leflutrozole; and licensing agreement with AstraZeneca. Mereo BioPharma Group plc was incorporated in 2015 and is headquartered in London, United Kingdom.