Merck has revealed detailed data for tulisokibart from a mid-stage trial in hidradenitis suppurativa that analysts say could help carve out a place in a crowded market that already includes AbbVie’s Humira and UCB’s Bimzelx.
Seventy-two percent of patients with hidradenitis suppurativa who took the high dose of Merck’s investigational anti-TL1A antibody in a Phase 2b trial saw their skin abscesses and inflammatory nodules reduced by at least 50%, hitting the study’s primary endpoint and setting up a push into late-stage development.
Among patients taking the medium dose of tulisokibart, 64% cleared this bar, Merck reported on Wednesday. Compared with placebo, these improvements represent a 37% and 29% advantage over placebo, respectively.
“This was a relatively small trial, but we view the data as compelling and favorable versus other commercial- and clinical-stage assets in a crowded HS landscape,” analysts at Guggenheim Partners wrote in a note on Wednesday, calling the data “impressive.” The trial included 149 patients who were randomly assigned to high, medium and low doses of the experimental drug tulisokibart or placebo.
BMO Capital Markets was also bullish about the data drop, which followed Merck’s August announcement that the trial had hit its primary and certain key secondary endpoints, though details were lacking at the time. With those data now in hand, BMO noted that Merck’s asset could be “highly competitive with leaders like [AbbVie’s] Humira and [UCB’s] Bimzelx.”
The placebo-corrected efficacy could position tulisokibart, which Merck acquired in April 2023 when it swallowed Prometheus Biosciences for $10.8 billion, as “potentially meaningfully differentiated” versus approved therapies, the analysts argued. They pointed out that 31% of patients treated with Humira saw 50% or greater improvement in skin lesions in the Phase 3 PIONEER II study.
BMO also noted tulisokibart’s longer dosing interval—once every four weeks—offers another key advantage over competitors such as Bimzelx, which needs to be administered every two weeks.
As for safety, Merck reported slightly higher rates of adverse events across the tulisokibart arms versus placebo, though the pharma noted that serious side effects were “infrequent” and were just as common across all study groups, including placebo. There were no serious or opportunistic infections—a finding that BMO said could “read positively to broader development in inflammatory conditions.”
Tulisokibart is being tested for a variety of immune-driven conditions, such as ulcerative colitis, rheumatoid arthritis and psoriatic arthritis.
In June, Merck said that tulisokibart met the primary endpoint of clinical remission in the Phase 3 ATLAS-UC study in ulcerative colitis, though the pharma didn’t reveal specific data.
In August, tulisokibart failed to hit a primary endpoint in a mid-stage trial for systemic sclerosis-associated interstitial lung disease, prompting the pharma to discontinue that study. While Merck did not specify which of the trial’s four primary endpoints tulisokibart failed, the company said no new safety concerns were identified. Because three of the endpoints were related to safety, this suggests that the change in amount of air able to be exhaled from baseline was the endpoint that missed.
