S3209 Efficacy of Ustekinumab Intravenously q12 Weeks for Maintenance Therapy for Crohn’s Disease

Introduction: Ustekinumab is a humanized monoclonal antibody that targets IL-12 and IL-23 used as induction and maintenance therapy for Crohn’s Disease. Ustekinumab is traditionally given as a weight based IV induction, followed by 90 mg subcutaneously every 8 weeks. Case Description/Methods: For many Medicare patients, subcutaneous dosing of ustekinumab is not often covered by insurance. In our case series, we evaluated 4 elderly patients with Crohn’s disease who were unable to afford subcutaneous ustekinumab therapy and thus were switched to ustekinumab IV every 12 weeks for maintenance. We assessed the efficacy of ustekinumab IV for maintenance, replacing the 90 mg subcutaneous every 8-week maintenance dose they had previously been on. All patients tolerated IV ustekinumab and no adverse events occurred to this point. Patients 1 and 2 achieved clinical and endoscopic remission after maintenance IV ustekinumab. Patient 3 achieved endoscopic remission but not clinical remission despite having 187 weeks of therapy. Patient 4 was recently switched to IV dosing and had 1 dose (11 weeks into IV therapy) so has not yet reached clinical remission and is awaiting a colonoscopy later this year to determine endoscopic remission. Patient 1 has reached a Simple Endoscopic Score for Crohn’s Disease (SES-CD) of 0 at week 52 of IV ustekinumab therapy but had a perianal fistula without active surrounding inflammation. Patient 3, while not reaching clinical remission due to small amount of blood with stools intermittently, has seen their SES-CD decrease from 9 to 2 over a 52-week period of IV ustekinumab therapy, with only erythematous mucosa in the rectum (Table 1). Discussion: Three patients achieved endoscopic remission with IV ustekinumab and 2 patients achieved clinical remission. No patients had any adverse events throughout their treatment course suggesting that one may consider IV maintenance therapy for certain patients unable to afford subcutaneous treatment long-term. Table 1. - Information of Patients on Ustekinumab Therapy Patient ID 1 2 3 4 Age 69 66 74 69 Gender Male Female Male Female Weight (kg) 60.6 89.4 69.3 80.1 Dosing (mg) 390 520 390 390 Location of Disease ileum, perianal ascending colon, ileum perianal, rectum ileitis, ileo-colonic anastomosis Prior Medications mesalamine, infliximab Infliximab, ertolizumab mesalamine mesalamine Pre-ESR 6 mm/hr (week 0) 6 mm/hr (week 26) Post-ESR 2 mm/hr (week 52) 2 mm/hr (week 52) Pre-CRP 2.7 mg/L (week 0) 2.6 mg/L (week 26) Post-CRP 1.9 mg/L (week 52) 4.8 mg/L (week 52) IV Therapy (Weeks) 196 84 187 11 kg - Kilograms; mg - milligrams.