Primary endpoint of the trial is reduction in the Ulcerative Colitis Disease Activity Index (UCDAI) at six weeks, while secondary endpoints include endoscopic remission, reduction in UCDAI at three weeks, and time to resolution of rectal bleeding; there are additional exploratory endpoints.
The company said that topline results of the double-blind, active-controlled trial will be available in April 2014.
Altheus founder and CSO Richard Harty said the ZA201 trial design sets a high hurdle for Zoenasa; superiority over mesalamine standard of care.
"Positive results will validate the entire Zoenasa platform, so we are pleased to have achieved this critical milestone," Harty said.
"Pending positive results from ZA201, we look forward to continuing development of Zoenasa Rectal Gel and accelerating development of Zoenasa Oral Tablets."
In the US, about 1.2 million suffer from inflammatory bowel disease and the first-line treatment for ulcerative colitis is mesalamine.
However, many patients do not achieve symptomatic or endoscopic remission and must escalate to more expensive treatments that also entail greater risks.
Zoenasa is a combination of two US Food and Drug Administration (FDA) approved drugs, with well-established efficacy and safety records and its intellectual property protection includes patents based on an unexpected synergy shown to improve the signs and symptoms of ulcerative colitis.
The FDA has granted Zoenasa orphan drug designation for the treatment of pediatric ulcerative colitis.
The company said that an oral formulation of Zoenasa is also being developed.
Image: H&E stain of a colonic biopsy showing a crypt abscess, a classic finding in ulcerative colitis. Photo: courtesy of KGH