Tulisokibart Meets Primary Endpoint in Phase 2b Hidradenitis Suppurativa Trial

Tulisokibart, an investigational anti-tumor necrosis factor-like cytokine 1A (TL1A) monoclonal antibody, met its primary endpoint of Hidradenitis Suppurativa Clinical Response 50 (HiSCR50) at week 16 in the phase 2b MK-7240-012 trial in moderate to severe hidradenitis suppurativa (HS), according to Merck.¹

Merck reported the results as the first positive phase 2 data for an anti-TL1A monoclonal antibody in dermatology, presented in a late-breaking session at the 2026 European Academy of Dermatology and Venereology (EADV) Congress (Abstract LB-26).¹ Tulisokibart blocks TL1A signaling and downregulates T helper 1 (Th1), Th2, and Th17 pathways, with the aim of disrupting the immuno-fibrotic loop Merck links to HS progression.¹ The agent previously induced clinical remission in a phase 2 ulcerative colitis trial.²

"Despite available advanced therapies, many still do not achieve long-term disease control," said Alexa B. Kimball, MD, MPH, lead investigator of the study, president and CEO of Harvard Medical Faculty Physicians at Beth Israel Deaconess Medical Center, and professor of dermatology at Harvard Medical School. "Results from the MK-7240-012 trial are promising and suggest the potential for meaningful improvement in the management of this difficult-to-treat condition."¹ Kimball is a paid consultant to Merck.¹

Tulisokibart HiSCR50 response in the MK-7240-012 trial

MK-7240-012 (NCT06956235) is a randomized, double-blind, placebo-controlled phase 2b study in patients with moderate to severe HS.³ Participants received high-dose (480 mg every 2 weeks), medium-dose (480 mg every 4 weeks), or low-dose (240 mg every 4 weeks) tulisokibart, or placebo, over a 16-week double-blind period. The trial used a Bayesian design augmenting concurrent placebo controls with historical placebo data for the primary endpoint.¹

At week 16, HiSCR50 was achieved by 72% of patients in the high-dose group (n = 42) and 64% in the medium-dose group (n = 42), compared with 35% in the placebo group (n = 44). These rates represent differences of 37 and 29 percentage points over placebo, respectively, and both regimens demonstrated superiority, according to Merck.¹

In an exploratory analysis, the low-dose group (n = 21) reached a 52% response rate, 17 percentage points above placebo.¹

HiSCR50 required at least a 50% reduction in total abscess and inflammatory nodule count, with no increase in abscesses or draining tunnels. The release from Merck did not report P values, confidence intervals, or posterior probabilities for the primary analysis.

Tulisokibart HiSCR75, quality of life, and safety in HS

For the non-ranked key secondary endpoints at week 16, HiSCR75 was achieved by 41% of high-dose, 40% of medium-dose, and 29% of low-dose patients, compared with 15% receiving placebo. Mean Dermatology Life Quality Index (DLQI) scores fell by 5.62 points from baseline in the high-dose group and 3.50 points in the medium-dose group, vs 2.46 points with placebo.¹ The low-dose group showed no DLQI improvement over placebo, and Merck characterized the secondary endpoint differences as numerical.¹

Adverse events occurred in 42.9%, 47.6%, and 52.4% of patients receiving high-, medium-, and low-dose tulisokibart, respectively, compared with 40.9% receiving placebo.¹ Serious adverse events occurred in 2.4% of the high- and medium-dose groups, 4.8% of the low-dose group, and 2.3% of the placebo group.¹ No serious or opportunistic infections were observed.¹

"We look forward to advancing tulisokibart to Phase 3 for patients living with HS," said Aileen Pangan, MD, vice president and therapeutic area head, immunology clinical research, Merck Research Laboratories.¹

Merck plans to use the findings to inform phase 3 development in HS.¹ Tulisokibart is in phase 3 trials for ulcerative colitis (ATLAS-UC) and Crohn disease (ARES-CD), and in phase 2 trials for rheumatoid arthritis, psoriatic arthritis, and radiographic axial spondyloarthritis.¹

References

1. Merck. Merck's tulisokibart met primary and key secondary endpoints in phase 2b study in patients with moderate to severe hidradenitis suppurativa (HS). Published September 30, 2026. Accessed October 1, 2026. https://www.businesswire.com/news/home/20260930948161/en/Mercks-Tulisokibart-Met-Primary-and-Key-Secondary-Endpoints-in-Phase-2b-Study-in-Patients-With-Moderate-to-Severe-Hidradenitis-Suppurativa-HS

2. Sands BE, Feagan BG, Peyrin-Biroulet L, et al. Phase 2 trial of anti-TL1A monoclonal antibody tulisokibart for ulcerative colitis. N Engl J Med. 2024;391(12):1119-1129. doi:10.1056/NEJMoa2314076. https://doi.org/10.1056/NEJMoa2314076

3. A phase 2b, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of tulisokibart in participants with moderate to severe hidradenitis suppurativa. ClinicalTrials.gov identifier: NCT06956235. Accessed October 1, 2026. https://clinicaltrials.gov/study/NCT06956235