ERA-63, also known as ORG-37663, as well as 3-methylene-7α-methyl-17α-ethynylestra-5(10)-en-17β-ol, is a synthetic, steroidalestrogen and a selectiveagonist of the ERα that was under development for the treatment of rheumatoid arthritis but was never marketed.[2][1] The drug produced estrogenic effects but failed to show effectiveness for rheumatoid arthritis in a phase IIaclinical study.[3][4] A large clinical trial also found that prinaberel (ERB-041), a selective ERβ agonist, was ineffective in the treatment of rheumatoid arthritis in spite of activity in preclinicalmodels.[4]
^ abJanssen GB, Penninks AH, Knippels LM, van Zijverden M, Spanhaak S (2008). "The evaluation of the immunomodulating properties of ERA-63 a pharmaceutical with estrogenic activity". Toxicol. Lett. 180 (3): 196–201. doi:10.1016/j.toxlet.2008.06.857. PMID18602456.
^Dulos J, Hofstra CL, Joosten L, Veening-Griffioen DH, Lucassen MA, Doorn CM, Graaf JH, Miltenburg A, Dijcks FA, Ederveen TH, Boots AM (2006). "A selective estrogen receptor alpha agonist (Org 37663) suppresses inflammation and arthritis in mouse models". Annals of the Rheumatic Diseases. 65: 128.
^van Vollenhoven RF, Houbiers JG, Buttgereit F, In 't Hout J, Boers M, Leij S, Kvien TK, Dijkmans BA, Szczepański L, Szombati I, Sierakowski S, Miltenburg AM (2010). "The selective estrogen receptor alpha agonist Org 37663 induces estrogenic effects but lacks antirheumatic activity: a phase IIa trial investigating efficacy and safety of Org 37663 in postmenopausal female rheumatoid arthritis patients receiving stable background methotrexate or sulfasalazine". Arthritis Rheum. 62 (2): 351–8. doi:10.1002/art.27196. PMID20112368.
