Ra Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company, develops therapeutics for the treatment of diseases caused by excessive or uncontrolled activation of the complement system. The company’s peptide chemistry platform enables the production of synthetic macrocyclic peptides that combine the diversity and specificity of antibodies with the pharmacological properties of small molecules. Its lead product candidate is Zilucoplan, an injection into the tissue under the skin that has completed Phase II clinical trial for the treatment of generalized myasthenia gravis (gMG); completed Phase II clinical trial for treating paroxysmal nocturnal hemoglobinuria (PNH); and completed Phase Ib clinical trial to treat patients with renal impairment. The company’s pre-clinical programs include Factor D inhibition for treating C3 glomerulonephritis and dense deposit disease, and inhibitors of other complement factors for renal, autoimmune, and central nervous system diseases. Ra Pharmaceuticals, Inc. was incorporated in 2008 and is based in Cambridge, Massachusetts. As of April 2, 2020, Ra Pharmaceuticals, Inc. operates as a subsidiary of UCB SA.