InDex Scraps Phase III Ulcerative Colitis Trial on Disappointing Data

Stocks Crashing_iStock, KanawatTH

Pictured: Red line graph showing a downward trend/iStock, KanawatTH

InDex Pharmaceuticals on Tuesday announced that it is discontinuing the Phase III CONCLUDE program, which was evaluating its investigational immunomodulatory therapeutic cobitolimod in ulcerative colitis.

The decision to terminate the late-stage study is in line with the recommendations of an Independent Data Monitoring Committee, which found during a planned dose selection, safety and futility analysis that cobitolimod is “unlikely” to meet the study’s primary endpoint, according to the company’s announcement.

At the same time, InDex noted that the committee’s advice to discontinue the study was not due to any safety concerns.

InDex CEO Jenny Sundqvist in a statement called the committee’s recommendation “surprising and disappointing,” adding that cobitolimod’s failure in CONCLUDE highlights the “complexity of the disease” and points to the need for more research to address the “high unmet medical need” in ulcerative colitis.

The company’s stock was trading approximately 59% lower on Wednesday morning in reaction to the news.

Cobitolimod is an investigational single-stranded DNA-based immunomodulatory sequence that, when delivered directly into the large intestine, seeks out and binds to the TLR9 protein found in immune cells and on epithelial cells.

The mechanism of action allows cobitolimod to facilitate the production of anti-inflammatory cytokines, countering the underlying pathologic mechanism of ulcerative colitis and healing wounds in the large intestine, according to InDex’s website.

InDex was running the Phase III CONCLUDE program to evaluate cobitolimod including Induction Study 1, which was designed to determine the best dose of cobitolimod and assess clinical remission after six weeks of cobitolimod treatment, while the Induction Study 2 was to use the best dose identified in the first study.

Data from Induction Study 1 was the basis for the Data Monitoring Committee’s recommendation to discontinue CONCLUDE.

Cobitolimod helped InDex score a partnership contract with Viatris, which in May 2023 paid $10 million upfront for the exclusive right to commercialize the candidate in Japan. The deal also involved $40 million in potential development and sales milestones, as well as up to double-digit percentage royalties based on net sales in Japan.

Tuesday’s Phase III failure for InDex comes a month after the ulcerative colitis space saw an explosive approval. In October 2023, the FDA finally gave the greenlight to Eli Lilly’s Omvoh (mirikizumab), a first-in-class monoclonal antibody indicated for moderately to severely active ulcerative colitis. A few days earlier, Roche made a $7.1 billion play to acquire Roivant subsidiary Televant Holdings, which is developing the anti-TL1A antibody RVT-3101 for inflammatory bowel diseases.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. He can be reached at or

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