P084 DEEP REMISSION WITH DOUBLE BIOLOGIC THERAPY: A SUCCESSFUL CASE OF COMBINATION USTEKINUMAB AND VEDOLIZUMAB FOR SEVERE REFRACTORY CROHN’S DISEASE

Background Stricturing Crohn’s disease (CD) constitutes a severe phenotype often associated with a high degree of morbidity (3). Surgical resection is first-line therapy for symptomatic strictures, but most patients relapse without subsequent medical therapy (4–5). Biologics are the mainstay for inducing and maintaining remission, but some cases are refractory despite maximum dosage of therapy. Reports of dual biological therapy (DBT) in refractory, stricturing CD are sparse, and prior case reports document only clinical remission (1). To contribute further knowledge regarding the use of DBT in stricturing CD, we present the case of a refractory CD patient who achieved deep remission with ustekinumab and vedolizumab. Case Presentation A 35 year old non-smoking, Caucasian male was referred to our clinic in 2014 for refractory CD complicated by multiple strictures. Prior to establishing care with us, he received two jejunal resections and a sigmoid resection. Previously failed therapies included azathioprine with infliximab, adalimumab, and certolizumab. He continued to progress under our care despite combination methotrexate/certolizumab, as well as methotrexate/golimumab. He underwent proctocolectomy with end ileostomy in 2015 and initiated vedolizumab q8weeks post-operatively. He reoccurred in 2018, when he presented with an ulcerated ileal stricture. He was switched from vedolizumab to ustekinumab q8weeks and placed on prednisone, but continued to progress, developing significant hematochezia requiring hospitalization and blood transfusions. Ileoscopy performed during hospital admission confirmed severe, ulcerating disease in the ileum with stricture. Ustekinumab dosing was increased to q4weeks, azathioprine was initiated, and he underwent stricturoplasty. Follow-up ileoscopy three months later revealed two ulcers in the neo- TI (Figure 1). Vedolizumab q8weeks was initiated in addition to ustekinumab q4weeks and azathioprine 125mg. After four months on this regimen the patient felt better, but follow-up ileoscopy showed two persistent ulcers in the neo-TI. Vedolizumab dosing interval was increased to q4weeks. After four months, subsequent ileoscopy demonstrated normal neo-TI (Figure 2). Histologic evaluation of biopsies confirmed deep remission of crohn’s disease. No adverse side effects have occurred with maximum doses of both ustekinumab and vedolizumab combination therapy. Discussion This case supports both the safety and efficacy of ustekinumab and vedolizumab dual biologic therapy for treatment of severe, refractory Crohn’s disease. While there are reports of DBT inducing clinical remission, this case supports efficacy for vedolizumab and ustekinumab combination therapy to induce deep histologic remission. Large practical clinical trials are needed to better investigate the safety and efficacy of DBT with vedolizumab and ustekinumab, but our case suggests this combination may be a safe and efficacious therapy for refractory CD patients.