INTRODUCTION: Ustekinumab is a recently approved immunosuppressive agent for management of moderate to severe Crohn's Disease (CD). In trials, dosing was determined at 6 mg/kg for induction with maintenance injection of 90 mg every 8 weeks. Approximately half of the patients in the UNITI Induction trials did not respond to ustekinumab treatment when assessed at 6-8 weeks, and were included in the Maintenance trial with ustekinumab provided at week 8 or 12. Only 30-40% of these patients continued to have remission at maintenance trial conclusion. We present a case series of two CD patients who were initiated on ustekinumab therapy but required a shortened maintenance dose interval to achieve/maintain remission. CASE DESCRIPTION/METHODS: Case 1: A 33 year old female presenting clinically with intermittent abdominal pain, diarrhea, occasional blood in stool & nocturnal symptoms was diagnosed with CD in 2017 via computed tomography of the abdomen combined with colonoscopy revealing terminal ileum aphthous ulceration. Previous therapies included budesonide, prednisone & adalimumab. Ustekinumab induction was initiated on 2/2/2018. However, on 3/20/2018, the patient developed severe abdominal pain consistent with a CD flare. Following, she has received ustekinumab injections every 4-6 weeks to maintain disease remission. Case 2: A 47 year old male initially diagnosed with CD at the age of 22, complicated by emergent colectomy with end ileostomy in 2014 presented with an acute flare consisting of abdominal pain, peristomal fistulas and increased ostomy output. Following evaluation, he underwent surgical correction of fistula, drainage of intraabdominal wall abscess & abdominal wall reconstruction in December 2018. Prior to this, he was treated with sulfasalazine, mercaptopurine, azathioprine along with immunomodulators including infliximab & certolizumab without adequate response. In January 2019, ustekinumab therapy was initiated with standard induction followed by injectable dosing every 4 weeks due to CD severity and physician recommendation. Following this schedule, the patient has had improved ostomy output and symptom control. DISCUSSION: In our experience, shortening the interval of injectable ustekinumab dosing to 4-6 weekly from 8 weeks has proven successful in maintaining remission for patients with severe CD. This subsegment of CD patients was excluded in trials and further investigation is needed to assess long term efficacy of shortened ustekinumab therapy intervals to maintain remission.