emicizumab emicizumab emicizumab, sold under the brand name hemlibra, is a humanized bispecific antibody for the treatment of haemophilia a, developed by genentech and chugai (a subsidiary of roche). a phase i clinical trial found that it was well tolerated by healthy subjects. emicizumabmonoclonal antibodytypewhole antibodysourcehumanizedtargetactivated factor ix, factor xclinical datatrade nameshemlibraother namesace910, emicizumab-kxwhahfs/drugs.commonographlicense data us dailymed: emicizumab us fda: emicizumab pregnancycategory au: b2 routes ofadministrationsubcutaneousatc codeb02bx06 (who) legal statuslegal status au: s4 (prescription only) ca: rx-only / schedule d us: ℞-only eu: rx-only in general: ℞ (prescription only) identifierscas number1610943-06-0drugbankdb13923chemspidernoneunii7nl2e3f6k3keggd10821 ychemical and physical dataformulac6434h9940n1724o2047s45molar mass145639.02 g·mol−1 in november 2017, it was approved in the united states for treatment of haemophilia a in those who had developed resistance to other treatments. it was subsequently approved by the us fda in april 2018 under the breakthrough therapy designation for treatment of haemophila a in those who have not developed resistance to other treatments. the u.s. food and drug administration (fda) considers it to be a first-in-class medication. mechanism of action emicizumab binds to both the activated coagulation factor ix and to factor x, mediating the activation of the latter. this is normally the function of coagulation factor viii, which is missing in haemophilia a patients.