Merck posts ‘encouraging’ Phase 3 ulcerative colitis data but Roche challenge looms

 

Given its intravenous route of administration, Merck’s tulisokibart will likely “need to be meaningfully improved” over Roche’s afimkibart, which can be given subcutaneously, BMO Capital Markets analysts said. Both assets are being tested for ulcerative colitis.

Merck’s investigational antibody helped patients with ulcerative colitis achieve clinical remission in a late-stage study—but analysts remain cautious about the asset’s prospects, given the dearth of information and competitive overhangs.

Indeed, the pharma did not reveal specific data in its news announcement on Monday, saying only that the therapy, an intravenous TL1A inhibitor dubbed tulisokibart, “successfully met its primary endpoint of clinical remission” at 12 weeks. Tulisokibart also met key secondary outcomes, though Merck didn’t specify which ones.

The company promised to disclose more detailed findings at an upcoming medical congress.

Without specific data, analysts remain uncertain about how tulisokibart will fare competitively. “Lack of detail meters upside,” BMO Capital Markets told investors in a Monday note. The firm acknowledged that Merck’s commentary around the outcome “appears encouraging,” but contended “we need to see full quantitative data . . . before we can appreciate the UC [ulcerative colitis] opportunity.”

BMO pointed to Roche’s afimkibart as a potential competitor. The pharma picked up the anti-TL1A antibody, which can be administered intravenously or subcutaneously, in its $7.1 billion acquisition of Telavant in October 2023. In the Phase 2b TUSCANY-2 study, 35% of UC patients on 15-mg afimkibart achieved clinical remission at 14 weeks versus 12% of placebo controls—setting a bar for Merck’s asset to clear.

“With Merck’s tulisokibart administered by IV and Roche’s afimkibart administered subcutaneously in the induction setting, tulisokibart’s efficacy would likely need to be meaningfully improved vs. afimkibart to be competitive and support strong preferential uptake if approved,” the analysts said.

Merck is nevertheless developing a subcutaneous formulation of tulisokibart for maintenance treatment, which BMO noted “could help lessen such headwinds to uptake.”

Guggenheim Partners, on the other hand, had a more optimistic view of Merck’s data, saying in a Monday note that the readout “supports our above-consensus estimates for the product.” The firm models peak sales of over $5 billion by the late 2030s, whereas consensus estimates hover around $4 billion.

The group was also more lenient about the lack of details. “While some investors might be disappointed that no quantitative efficacy data were shared at this time, we would note that this is consistent with how MRK has historically toplined its data,” the analysts said.

Beyond ulcerative colitis, Merck on Monday said it is running several other trials of tulisokibart, including for Crohn’s disease, systemic sclerosis-associated interstitial lung disease and rheumatic arthritis.

https://www.biospace.com/drug-development/merck-posts-encouraging-phase-3-ulcerative-colitis-data-but-roche-challenge-looms