A178 USTEKINUMAB FOLLOWING PRIMARY ANTI-TNF FAILURE AND SECONDARY LOSS OF RESPONSE TO VEDOLIZUMAB IN AN ADOLESCENT WITH ULCERATIVE PANCOLITIS

Abstract Background Infliximab is, to date, the only biologic therapy approved for treatment of ulcerative colitis (UC) in paediatric patients. Although often effective, primary mechanistic failure is more common UC than luminal inflammatory Crohn’s disease (CD). Alternate pathway biologics, specifically vedolizumab (anti-α4β7 integrin) and ustekinumab (anti-interleukins 12/23) are increasingly used adults with UC. Emerging data from head trials biologics network meta-analyses placebo-controlled trial being guide choice sequencing therapeutic agents. Even among concerning combination very limited. Aims To report outcomes addition a patient steroid dependent colitis, previous non-response infliximab secondary loss response monotherapy. Methods Case Results A 17 years old girl was hospitalized acute severe (PUCAI 85) developing as oral prednisone tapered below 30 mg daily despite ongoing intensified (300 q4 weekly) per rectal steroids. First presentation 2 earlier pancolitis, responsive prednisone, maintained on 5-ASA until first exacerbation 8 months later. Responsive then IV steroids, but unable maintain steroid-free remission levels. Vedolizumab initiated setting anti-TNF failure. Steroid-free clinical 7 q weekly dosing normalization fecal calprotectin (16, 115 µg/g) when symptoms recurred persisted shortening interval 4 weeks. level 34 µg/mL. Symptomatic 40 mg, unsustained tapering. Hospitalized up 10 bloody stools day, nocturnal stools, abdominal pain anemia requiring blood transfusion. High doses steroids were given slow response. Colectomy refused by family. 390 given. continued view prior responsiveness. Ustekinumab subcutaneous maintenance at week continuing (levels 3.3 mg/L). Oral discontinued. At 5 post initiation, 0). Fecal has declined >1800 723 µg/g. Conclusions In this anti-TNF, demonstrated short-term efficacy alleviating steroid-dependency. The contribution vedolizumab, which there had previously been response, unknown. Nevertheless, safety profile allows it be combined other therapies selected treatment-refractory Funding Agencies None