Ulcerative colitis (UC) a type of inflammatory bowel disease (IBD) which is a long term condition that causes inflammation and ulcers in the bowel and rectum which can bleed and produce pus. UC is thought to be caused when the immune system mistakes harmless bacteria inside the bowel as a threat and attacks the tissues of the colon, causing inflammation. The main symptoms of UC include recurring diarrhoea (why may contain blood, mucus or pus), abdominal pain and feeling the need to empty your bowels more frequently. The symptoms of UC often follow a pattern of periods of very mild or no symptoms (remission) followed by periods of increased symptoms (relapse or active disease).
Ustekinumab is a drug which is given as an injection and works by blocking the molecules that are involved in the inflammation which occurs in UC. Ustekinumab is already licenced for use in people with Crohn’s disease, which is another type of IBD. If ustekinumab is licenced this would provide another treatment option for people with moderate to severe active UC.
Etrolizumab is a new monoclonal antibody (an immune protein) delivered by subcutaneous injection. The treatment works by targeting molecules called integrins to control the immune response and prevent the accumulation of immune molecules, which cause inflammation in individuals with a form of ulcerative colitis where inflammation is not mediated by a signalling protein called tumour necrosis factors (TNF) alpha (‘non-TNF-α’) and who are therefore intolerant to TNF blockers. This represents a new target group as current therapies focus mainly on anti-TNF inflammation. In one study, etrolizumab showed a greater reduction of intestinal lymphocyte infiltration in comparison to standard treatment.