With pharma heavyweights clashing against one another and reeling in major sales in the ulcerative colitis (UC) arena, Merck is making advances in the field with the key prize of its $11 billion buyout from several years ago.
Tulisokibart, an anti-TL1A antibody picked up in Merck’s purchase of Prometheus Biosciences in 2023, has delivered a positive result in the ATLAS-UC induction-only study of patients with moderately to severely active UC, Merck reported on Monday.
In the study, the drug showed a benefit versus placebo on the primary endpoint of clinical remission, as measured by the Modified Mayo Score, at week 12, Merck said in a June 22 press release.
The result represents the first time an anti-TL1A antibody has delivered a positive result on clinical remission after 12 weeks in the patient population, Merck said. The drugmaker stopped short of offering specifics on the data but noted that “no safety concerns were identified.”
Merck plans to share detailed results from the study—and those from an ongoing induction and maintenance study—at an upcoming scientific congress and with regulators, the company said.
As it stands, the ulcerative colitis space features several entrenched brands with varying mechanisms of action, such as Takeda’s anti-integrin antibody Entyvio, AbbVie’s anti-IL-23 antibody Skyrizi and its JAK inhibitor Rinvoq, as well as Johnson & Johnson’s IL-23 inhibitor Tremfya. Several other older medicines such as AbbVie’s Humira and J&J’s Stelara also treat the condition and are facing biosimilar competition.
Merck’s tulisokibart represents one member in a new class of immunology medicines that also features candidates from Spyre Therapeutics, the newly launched biotech Bionyra, and partners Sanofi and Teva, among others. Besides UC, Merck is testing its candidate in Crohn's disease, rheumatoid arthritis, psoriatic arthritis and other immune-mediated inflammatory diseases.
In a note to clients Monday, analysts with Citi noted that until market watchers are able to assess the full data on tulisokibart, it’s reasonable to expect the drug will take a back seat to “current IL-23s and/or JAKs” unless it's able to show “maintenance, endoscopic, histologic-endoscopic, or biomarker differentiation.”
Meanwhile, Merck generates about half of its sales from its oncology megablockbuster Keytruda, so the company is busy advancing its pipeline and scouting for new opportunities ahead of the medicine’s eventual tumble over the patent cliff later this decade. Merck’s exec team is aware of the urgency, having inked several M&A deals in recent years to reposition the company ahead of the cliff.
Since the Prometheus buyout, Merck has also struck multibillion-dollar acquisitions of Verona Pharma, Cidara Therapeutics and Terns Pharmaceuticals to get its hands on a range of late-stage and commercial assets.
In the wake of the tulisokibart trial result, Citi analysts said they “need additional late-stage validation from Merck's recent acquisitions before gaining confidence the pipeline has fully overcome Keytruda LOE concerns.”