Merck & Co Inc. (NYSE:MRK) on Wednesday presented initial results from its Phase 2b MK-7240-012 trial at the European Academy of Dermatology and Venereology (EADV) 2026 Congress.

Phase 2b Trial Delivers Positive Results

The study evaluated tulisokibart, an investigational monoclonal antibody targeting tumor necrosis factor-like cytokine 1A (TL1A), in patients with moderate to severe hidradenitis suppurativa.

The trial met its primary endpoint of Hidradenitis Suppurativa Clinical Response 50 (HiSCR50) at week 16, with active regimens outperforming placebo.

In the high-dose group (480 mg Q2W, n=42), 72% of patients achieved HiSCR50, while 64% of medium-dose patients (480 mg Q4W, n=42) hit the endpoint.

These results represent a 37% and 29% improvement over the placebo group (35%, n=44), respectively.

In an exploratory analysis, low-dose participants (240 mg Q4W, n=21) recorded a 52% response rate, exceeding placebo by 17%.

Secondary Endpoints And Quality Of Life

Key secondary endpoints at week 16 showed numerical improvements across active doses. HiSCR75 response rates reached 41% for high-dose, 40% for medium-dose, and 29% for low-dose cohorts, compared to 15% for placebo.

Patients also reported quality of life enhancements. High-dose patients achieved a mean Dermatology Life Quality Index reduction of -5.62 from baseline, marking a 3.16-point advantage over placebo.

Medium-dose participants recorded a -3.50 reduction, showing a 1.02-point gain over placebo, while low-dose patients showed no improvement over the placebo reduction of -2.46.

Safety Profile And Future Expansion

Tulisokibart maintained a safety profile comparable to placebo. Adverse events affected 42.9% of high-dose, 47.6% of medium-dose, and 52.4% of low-dose participants, compared to 40.9% in the placebo arm.

Serious adverse events remained low across groups, ranging from 2.4% to 4.8% versus 2.3% for placebo, with no serious or opportunistic infections reported.

Tulisokibart currently features the broadest anti-TL1A development program, spanning six disease indications including Phase 3 trials in ulcerative colitis and Crohn's disease.

MRK Price Action: Merck shares were down 1.63% to $146.85 at the time of publication on Wednesday, according to market data.