The biologic drug, vedolizumab, met the goals of the Phase III trial with highly statistically significant advantages in rates of remission, clinical response and bowel healing compared with a placebo, researchers said.

Of the patients taking part in the year-long maintenance study, 44.8 percent of those who received vedolizumab every four weeks and 41.8 percent who got the drug every eight weeks were deemed to be in clinical remission at week 52. That compares with 15.9 percent for those who received a placebo.

In a subset of patients who were not also taking a steroid for the condition, the remission rate was 45.2 percent for those who got the Takeda drug every four weeks compared with 13.9 percent in the placebo group.

"The maintenance study data are really spectacular," said Dr Brian Feagan, the trial's lead investigator who presented the data on Tuesday at the Digestive Disease Week meeting in San Diego.

"I think this is a pretty exciting result and has big implication for patient care ultimately," added Feagan, who said he believes the data to be strong enough for the drug to gain approval.

Clinical remission was defined as a score of 2 points or less on the 12-point Mayo scale of disease activity. A Mayo score of 6-12 indicates moderate-to-severe disease.

Ulcerative colitis is a chronic condition that affects roughly 700,000 Americans, and often strikes younger, active people. Common symptoms include diarrhea, rectal bleeding, incontinence, abdominal pain, fever, fatigue and weight loss.

The ulcerative colitis market is expected grow nearly 6 percent annually to about $3 billion by 2020, according to a recent report from Decision Resources, which provides analysis of biopharmaceutical industry data.

Vedolizumab, which is given intravenously, belongs to a different class of biologic drugs than the TNF blockers widely used to treat colitis and other inflammatory diseases, such as Johnson & Johnson's Remicade and Abbott Laboratories' Humira. The drug targets a protein present in a small percentage of white blood cells that have been shown to play a role in controlling inflammation.

The anti-TNF drugs, while highly effective, suppress the immune system and have been associated with infections and other serious complications, such as tuberculosis.

"It would be nice to have a drug that didn't do that," Feagan said. "There was no increased risk of serious infection or any infection over placebo. It's pretty striking actually."

NO PML CLOUD

The Takeda drug works in a similar manner to Biogen Idec's multiple sclerosis drug Tysabri, which has been associated with a rare, potentially fatal brain infection known as PML. Feagan said vedolizumab is more selective and works on the gut and not the brain so is unlikely to carry a similar risk. "It should not have a PML cloud," Feagan said.

He said he expects the Takeda drug would initially be used after anti-TNF therapy stops working or in patients who cannot tolerate those drugs. But he believes it may eventually supplant TNF blocker therapy.

About 40 percent of those in the nearly 900-patient study had previously been treated with a TNF blocker, Feagan said.

In addition to remission rates, researchers looked at the rate of durable clinical response and bowel improvement, or mucosal healing, at week 52.

For those who received the Takeda drug every eight weeks, 56.6 percent had a durable clinical response, such as a significant easing of symptoms, as did 52 percent who got the drug every four weeks. That compared with 23.8 percent in the placebo group.

Clinical response was defined as a drop of 3 points on the Mayo scale, at least a 30 percent reduction in the overall score, and significant improvement in rectal bleeding.

The mucosal healing rate at week 52 was 51.6 percent for vedolizumab once every eight weeks and 56 percent for every four-week therapy, compared with 19.8 percent for placebo.

Patients in the study began with a six-week induction phase in which they got an initial 400 milligram dose of the drug to start and another 400 mg dose at week 2 before moving into the maintenance phase for the next 46 weeks.

(Reporting by Bill Berkrot in New York; editing by Matthew Lewis)

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