Celgene Corp. said Otezla improved the symptoms of patients with active ulcerative colitis in a phase 2 study.

Ulcerative colitis is a chronic, relapsing inflammatory bowel disease that causes long-lasting inflammation and ulcers in the lining of the large intestine.

The study was conducted in 170 patients who had failed in at least one conventional therapy but did not receive prior biologic therapy. The primary endpoint of the trial is total Mayo score clinical remission at week 12, with partial Mayo score as a secondary endpoint.

The Mayo score is a scale used to measure the severity of ulcerative colitis using four categories: stool frequency, rectal bleeding, endoscopic findings and physician's global assessment.

At week 12, 21.8% of the patients who received a 40-milligram dose of Otezla achieved clinical remission, compared to placebo's 13.8%. Meanwhile, 31.6% of patients treated with Otezla in a 30-milligram dosage achieved clinical remission, versus 13.8% for placebo.

Celgene said a phase 3 program for the drug is expected to begin in 2018.

Otezla, or apremilast, is approved to treat active psoriatic arthritis and moderate to severe plaque psoriasis candidate for phototherapy or systemic therapy.