Sucampo Pharmaceuticals has announced the pooled data from post-hoc analyses of the two pivotal Phase 3 studies of Amitiza (lubiprostone), used for the treatment of irritable bowel syndrome with constipation (IBS-C).

Amitiza is a chloride channel activator indicated for the treatment of chronic idiopathic constipation (CIC) in adults and for IBS-C in women aged 18 years and above.

In the two pivotal Phase 3 placebo-controlled 12-week studies, patients were randomised in a 2:1 ratio to receive lubiprostone 8mcg or placebo twice daily (BID), to assess improvements in subsets of patients with moderate to very severe IBS-C.

"Lubiprostone was well tolerated throughout the study."

Patients treated with lubiprostone showed considerable reduction in abdominal pain overall on a weekly basis over 12 weeks of treatment, with 35.1% of patients reporting a 30% or greater reduction in abdominal pain compared to baseline.

Sucampo Pharmaceuticals chair CEO and chief scientific officer, Ryuji Ueno, said IBS-C can be a painful disease with a range of abdominal symptoms, including abdominal pain, the severity of which has been associated with altered tight junction protein expression and distribution.

"The data from this analysis adds to our understanding of Amitiza, a chloride channel activator, in its role in the treatment of moderate to very severe IBS-C," Ueno added.

Lubiprostone was well tolerated throughout the study, with the common adverse events being nausea, headache and diarrhoea.

Sucampo Pharmaceuticals is focused on the discovery, development and commercialisation of drugs based on prostones that occur naturally in the human body as a result of enzymatic transformation of certain fatty acids.