Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory relapsing disorder affecting the gastrointestinal tract and is characterized by a progressive and unpredictable disease course.The two goals of therapy are the achievement of remission (induction) and the prevention of disease flares (maintenance). Medical therapy for IBD has advanced dramatically in the last decade with the introduction of targeted biologic therapies including infliximab,adalimumab and ustekinumab.There is paucity of head-to-head studies comparing the effectiveness of ustekinumab and adalimumab in inflammatory bowel disease patients especially in Egyptian population which prompted this study to be conducted.

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory relapsing disorder affecting the gastrointestinal tract and is characterized by a progressive and unpredictable disease course. There has been a global rise in the incidence of IBD over the last few decades, in 2017; there were 6.8 million cases of IBD globally. The age-standardized prevalence rate increased from 79.5 per 100, 000 population in 1990 to 84.3 per 100, 000 population in 2017. The annual incidence of Crohn's disease is 5.0 per 100,000 person-years in Asia and the Middle East, whereas incidence rates of ulcerative colitis are 6.3 per 100,000 person-years in Asia and the Middle East. The male-to-female ratio is approximately 1:1 for ulcerative colitis and Crohn's disease, with females having a slightly greater incidence. Both diseases are most commonly diagnosed in young adults (i.e., late adolescence to the third decade of life). Although the etiology of IBD remains largely unknown, it involves a complex interaction between the genetic, environmental or microbial factors and the immune responses. The symptoms of IBD include: diarrhea (often loose and watery with Crohn's disease or bloody with ulcerative colitis), severe or chronic cramping pain in the abdomen, loss of appetite leading to weight loss, fatigue, fever, rectal bleeding, joint pain and skin problems, such as rashes. The two goals of therapy are the achievement of remission (induction) and the prevention of disease flares (maintenance). Medical therapy for IBD has advanced dramatically in the last decade with the introduction of targeted biologic therapies including infliximab,adalimumab and ustekinumab, the optimization of older therapies, including rugs such as immunomodulators and 5-aminosalicylic acid (5-ASA), and a better understanding of the mucosal immune system and the genetics involved in the pathogenesis of IBD.

Adalimumab (ADA) is a monoclonal immunoglobulin G1 antibody that binds with high affinity and specificity to human TNF. ADA is an anti-TNF agent that has been shown to be effective in inducing and maintaining remission in patients with IBD at an induction dose of 160/80 mg (week 0 and 2) and at a maintenance dose of 40 mg every other week. The efficacy of adalimumab as a second-line therapy has also been documented for patients with loss of response or intolerance to infliximab. Ustekinumab, the monoclonal antibody to the p40 subunit of interleukin IL-12 and IL-23, has been approved in 2016 for the use in patients with moderate to severe active Crohn's disease (CD) and it was approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe ulcerative colitis in October 2019. The administration of ustekinumab for induction is intravenous and weight-based followed by a subcutaneous dose injection with a fixed dose (90 mg) for maintenance.

There is paucity of head-to-head studies comparing the effectiveness of ustekinumab and adalimumab in inflammatory bowel disease patients especially in Egyptian population which prompted this study to be conducted.

Inclusion Criteria:

• Age:18 year old or more.
• Gender: both male and female patients.
• Patients with IBD diagnosis established by clinical, laboratory and endoscopic findings.
• Moderate to severe inflammatory bowel disease patients.

Exclusion Criteria:

• Age less than 18 years.
• Malignancy.
• Pregnant women.

A comparative, prospective, observational cohort study will be conducted. Patients will be selected according to the inclusion and the exclusion criteria.

Patient's clinical data will include: age, sex, surgical history and associated comorbidities.

The patients will be divided into two groups:

Group 1 is adalimumab group Group 2 is ustekinumab group The follow up duration will be six months for each patient. Follow up duration: six months.

Parameters will be monitored in both groups during the study period as:

C-reactive protein (CRP) , complete blood count (CBC) and clinical scores.