New HS Biologics: TL1A vs IL-1 Beta Inhibition Results

Three separate controlled trials presented at the European Academy of Dermatology and Venereology 2026 Congress in Vienna show major clinical benefits for targeted treatments in hidradenitis suppurativa, positioning new biological therapies for upcoming phase 3 evaluation.

Key Clinical Takeaways:
• Tulisokibart, targeting TL1A, achieved a 71% response rate for HiSCR50 in its highest-dose group during a multicenter phase 2b trial.
• Abdakibart, targeting IL-1 beta, demonstrated significant improvements in HiSCR75 and IHS4 scores across two distinct dosing regimens in the LOTUS trial.
• Both monoclonal antibodies reported clean safety profiles without signals requiring heightened clinical monitoring.

Tulisokibart Dose-Response in Phase 2b Trials

In the multicenter phase 2b trial evaluating tulisokibart, 149 patients with moderate to severe hidradenitis suppurativa were randomized across three dosing regimens or a placebo group. The trial met its primary endpoint of a 50% or greater reduction in total count of abscesses and nodules—known as HiSCR50—at week 16. Patients in the high-dose group receiving 480 mg every 2 weeks achieved a 71% response rate with a P value of .001 relative to 41% for placebo. The medium-dose group receiving 480 mg every 4 weeks reached a 64% response rate with a P value of .012. The low-dose group receiving 240 mg every 4 weeks recorded a 53% response rate, which did not reach statistical significance.

This is an exciting new day. This is the first time that we have seen what TL1A inhibition can do, Alexa B. Kimball, MD, MPH, professor of dermatology and a researcher at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, reported during the late-breaker session in Vienna.

For the more rigorous HiSCR75 endpoint, the two highest-dose groups recorded significant response rates of 41% and 40%, respectively, compared with 15% for the placebo group. Dermatology Life Quality Index scores improved by 5.6 points in the high-dose group, 3.5 points in the medium-dose group, and 2.6 points in the placebo group. Tulisokibart is being evaluated for rheumatoid arthritis, psoriatic arthritis, and inflammatory bowel disease, with safety data characterized as clean across these indications.

Abdakibart Efficacy in the Phase 2 LOTUS Trial

The phase 2 LOTUS trial evaluated abdakibart in 167 patients with moderate to severe hidradenitis suppurativa, where approximately 40% of participants had received prior biologics. Patients were randomized to receive either 150 mg every 2 weeks, 300 mg every 4 weeks, or a placebo. For the rigorous HiSCR75 primary endpoint, 42.2% of patients in the 150-mg cohort and 42.9% in the 300-mg cohort achieved the threshold, both outperforming the 25.6% response seen in the placebo arm with a P value of .015.

These findings validate IL-1 beta as a promising new mechanism of action for the control of HS, Martina L. Porter, MD, vice chair of research and academics in the department of dermatology at Beth Israel Deaconess, reported.

International Hidradenitis Suppurativa Severity Score reductions at 16 weeks showed even wider margins against placebo. The 300-mg dose reduced IHS4 activity by 15.9 points (P = .002) and the 150-mg dose reduced it by 14.5 points (P = .012), compared with an 8.2-point reduction in the control group. For IHS4-55 responses, 59.5% of the 300-mg group and 57.8% of the 150-mg group achieved the benchmark versus 36% for placebo. For IHS4-75, rates reached 40.5% and 44.6% against 23.3% for placebo. Total abscesses, inflammatory nodules, and draining tunnels fell by 10.4 points in the 300-mg group and 9.1 points in the 150-mg group, compared with 6.0 points for placebo. Safety data for abdakibart were similarly reported as clean.

Phase 3 clinical trials are already underway or planned for tulisokibart, abdakibart, and an investigational agent targeting both IL-1 alpha and IL-1 beta, following the positive data presentations in Vienna.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.