Q&A: Tulisokibart Safety Findings, IBD Overlap, and Phase 3 Questions in HS

Safety data from the phase 2b MK-7240-012 trial (NCT06956235) of tulisokibart in moderate to severe hidradenitis suppurativa (HS) showed adverse event rates broadly comparable between active treatment and placebo through 16 weeks.¹

Alexa B. Kimball, MD, MPH, professor of dermatology at Harvard Medical School, president and CEO of Harvard Medical Faculty Physicians at Beth Israel Deaconess Medical Center, served as lead investigator of this analysis, presented as a late-breaking abstract during the 2026 European Academy of Dermatology and Venereology (EADV) Congress.

Adverse events (AEs) were seen in 42.9%, 47.6%, and 52.4% of subjects given the high, medium, and low doses of the anti-TL1A antibody, respectively, as opposed to the AEs seen in 40.9% with placebo.¹ Serious AEs impacted 2.4% of those involved in each of the 2 higher-dose arms of the study, 4.8% in the low-dose arm, and 2.3% with placebo. According to Merck, no serious or opportunistic infections were found by Kimball et al.

Efficacy followed a clear dose response. HiSCR50 at week 16 reached 72% with tulisokibart 480 mg every 2 weeks and 64% with 480 mg every 4 weeks, vs 35% with placebo, while the 240 mg every-4-week arm reached 52% in an exploratory analysis.¹˒² Merck has noted plans to advance tulisokibart into phase 3 in the HS space.

Kimball sat down with HCPLive at EADV 2026 in Vienna to discuss the safety profile, the overlap between HS and inflammatory bowel disease (IBD), and the open questions phase 3 data may need to answer:

HCPLive: What did the trial show regarding safety and tolerability, and are there signals clinicians should watch as development continues?

Alexa Kimball, MD, MPH: With the important reminder that this was an early phase study with a limited number of patients, the safety profile reported in the study was very reassuring. If you look across the pattern of the types of events we’re seeing, it’s what we would expect in any study in HS. Sometimes patients’ HS got worse. There were a few other distributed types of events, but no distinctive pattern, and none of the types of things we sometimes see in some of our other studies. So we were reassured by the data we’ve seen so far.

HCPLive: TL1A inhibition is also being studied in inflammatory bowel disease. How might a therapy relevant to both conditions fit into care?

Alexa Kimball, MD, MPH: One of the appealing things about therapies that might work for both inflammatory bowel disease and HS is that there is definitely an increase in the prevalence of both diseases. They do co-associate in these populations, and some of our patients who are harder to treat, I would argue, also have inflammatory bowel disease. One plus is that in patients who have both, you have the ability to treat both.

I think the other important thing is that some of the other agents used in HS have a less good profile in terms of inflammatory bowel disease. So for patients at risk, if you have something that actually treats both, that’s very reassuring, say, for patients with a family history, where you might want to mitigate that risk when you select your therapies. Again, we’re very pleased to see drugs developed in both of those areas at the same time.

HCPLive: What questions remain unanswered, and what would you most like to see from the phase 3 data?

Alexa Kimball, MD, MPH: We’re looking forward to the phase 3 program that’s been announced, and I think a core question will be, of course, where the efficacy lands and where the safety lands. This phase 2 program had a very nice dose response across the different dosing arms: low, medium, and high. So one of the important things will be which dose is selected, to figure out how we optimize both safety and efficacy for patients going forward. Again, at the highest dose, you see really high-tier efficacy, so figuring out the right dose over time is important.

One thing we also see in HS is that initial loading doses can sometimes be higher than the maintenance doses, and that helps get over the barrier of inflammation. So I would say the dosing calculations, based on the modeling the data present around pharmacokinetics and other factors, will be really important.

Editor’s Note: This transcript has been edited for grammar and clarity using artificial intelligence tools. Kimball has reported serving as a paid consultant for Merck.

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 November 3, 2026. https://s2.q4cdn.com/584635680/files/doc_news/Mercks-Tulisokibart-Met-Primary-and-Key-Secondary-Endpoints-in-Phase-2b-Study-in-Patients-With-Moderate-to-Severe-Hidradenitis-Suppur-QPD75.pdf.

2. Smith T. Tulisokibart shows phase 2b efficacy in moderate to severe HS. HCPLive. Published September 30, 2026. Accessed November 3, 2026. https://www.hcplive.com/view/tulisokibart-phase-2b-efficacy-moderate-severe-hs.