Renzapride

IBS is a functional gastrointestinal disorder characterised by recurrent symptoms of abdominal pain and discomfort associated with disturbed bowel function, which may also be accompanied by a feeling of bloating. Patients may have constipation-predominant IBS (“IBS-C”), mixed-symptom IBS (“IBS-M”) or diarrhoea-predominant IBS (“IBS-D”).

Renzapride was being developed by Alizyme for the treatment of IBS-C and for IBS-M. It is both a 5-HT₄ receptor full agonist (which acts as a pro-kinetic, enhancing motility) and a 5 HT₃ receptor antagonist (which can reduce pain and diarrhoea).

Renzapride has completed an extensive Phase I and Phase II clinical development programme, a ‘Thorough Cardiovascular Safety’ trial in healthy volunteers and a Phase III pivotal efficacy study in over 1,800 female IBS-C patients.

Renzapride has been shown to be safe and well tolerated in both IBS-C and IBS-M patients in Phase I and Phase II studies. Phase II clinical data showed up to 25% improvement on relief of overall IBS symptoms over placebo. The ‘Thorough Cardiovascular Safety’ trial showed that renzapride has no propensity to cause disturbances in heart rhythm at the therapeutic dose (4mg) and at a dose five times this level (20mg).

Headline results from the Phase III study in April 2008 showed renzapride to be safe and well tolerated, but demonstrated limited efficacy. As a consequence, Alizyme has discontinued all further investment in the clinical development of renzapride.