Tofacitinib, sold under the brand Xeljanz, Neojanz among others, is a medication used to treat rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, polyarticular-course juvenile idiopathic arthritis, and ulcerative colitis. It is a janus kinase (JAK) inhibitor, discovered and developed by the National Institutes of Health and Pfizer.
{{Drugbox | Watchedfields = changed | verifiedrevid = | image = Tofacitinib.svg | image_class = skin-invert-image | width = | alt = | caption = | pronounce = | tradename = Xeljanz, Neojanz, Jaquinus, Tofacinix, Others | Drugs.com = | MedlinePlus = a613025 | DailyMedID = Tofacitinib | pregnancy_AU = D | pregnancy_AU_comment = | pregnancy_category = | routes_of_administration = By mouth | class = Janus kinase (JAK) inhibitor | ATC_prefix = L04 | ATC_suffix = AF01 | ATC_supplemental = | legal_AU = S4 | legal_AU_comment = | legal_BR = | legal_BR_comment = | legal_CA = Rx-only | legal_CA_comment = | legal_DE = | legal_DE_comment = | legal_NZ = | legal_NZ_comment = | legal_UK = POM | legal_UK_comment = | legal_US = Rx-only | legal_US_comment = | legal_EU = Rx-only | legal_EU_comment = | legal_UN = | legal_UN_comment = | legal_status = Rx-only
| bioavailability = 74% | protein_bound = 40% | metabolism = Liver (via CYP3A4 and CYP2C19) | metabolites = | onset = | elimination_half-life = 3 hours | duration_of_action = | excretion = Urine
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).