April 13 (Reuters) - Spyre Therapeutics said on Monday its experimental drug showed a significant reduction in disease activity when ⁠tested in patients with ulcerative colitis in a mid-stage study, sending its shares up 34.5%.

The drug, SPY001, met the trial's main ⁠goal by reducing a key measure of tissue-level inflammation after 12 weeks of treatment, the drug ⁠developer said.

Ulcerative colitis is a chronic ‌inflammatory disease causing swelling and ulcers in the lining of the colon and rectum.

The Waltham, Massachusetts-based company said it expects the inflammatory bowel disease market to reach about $40 billion by 2030.

In the study, 40% of patients achieved clinical remission and 51% showed visible improvement in intestinal ‌tissue.

Spyre Chief Executive Cameron Turtle said the efficacy data for SPY001 exceeded ​results reported ‌for each individual component of Johnson & Johnson’s VEGA (mid-stage) ‌combination trial nPn6y1whna.

"On certain endpoints, our SPY001 monotherapy matched or even exceeded the efficacy of J&J's combination," Turtle ⁠said on a call with analysts.

Six patients reported treatment-emergent ‌adverse events during the ⁠induction period, including one serious event ​unrelated to Spyre's drug. The most common ‌side effect was back pain, which was reported by two patients.

The mid-stage trial has two parts: an initial open-label phase followed by a randomized, placebo-controlled phase testing multiple Spyre ​drugs alone and in combination.

SPY001 is designed to build on ‌the ‌activity of Takeda Pharmaceutical's Entyvio, with a longer-lasting effect and higher induction dosing, Spyre said.

"If ‌SPY001 indeed shows superior ​efficacy in placebo-controlled trials, it could take away Entyvio's market share, even if marketed as a monotherapy," said Jones Trading analyst Debanjana Chatterjee.

Takeda's Entyvio was approved by ⁠the U.S. Food and Drug Administration for ulcerative colitis in May ‌2014, followed by a subcutaneous version in September 2023.

(Reporting by Siddhi Mahatole in Bengaluru; ​Editing by Tasim Zahid and Shailesh Kuber)