Introduction: Obesity contributes to inflammation and may decrease psoriasis treatment efficacy. We investigated whether obesity affects the efficacy and safety of tildrakizumab, an anti-interleukin-23 p19 antibody approved for the treatment of adults with moderate-to-severe plaque psoriasis, for scalp psoriasis treatment.
Methods: This was a subgroup analysis of a randomized, double-blind, placebo-controlled, Phase 3b trial in patients with moderate-to-severe plaque psoriasis affecting the scalp. Patients receiving tildrakizumab 100 mg or placebo were analyzed by baseline obesity status (body mass index ≥ 30 versus < 30 kg/m2). Efficacy outcomes included an Investigator Global Assessment (IGA) modified 2011 (scalp) (IGA mod 2011 [scalp]) score of "clear"/"almost clear" (0/1) with a ≥ 2-point reduction (IGA mod 2011 [scalp] response), ≥ 90% improvement in Psoriasis Scalp Severity Index (PSSI) score (PSSI 90 response), ≥ 4-point reduction in Scalp Itch-Numeric Rating Scale (Scalp Itch-NRS response; among patients scoring ≥ 4 at baseline), and percent change from baseline (%CFB) in affected scalp surface area (SSA). Safety was assessed from adverse events. The analysis was not prospectively powered to detect differences between subgroups.
Results: In the intention-to-treat population, 56/117 (47.9%) patients randomized to tildrakizumab and 57/114 (50.0%) to placebo had obesity (modified intention-to-treat population: tildrakizumab, 43/89 [48.3%]; placebo, 40/82 [48.8%]). At Week 16, significantly more patients treated with tildrakizumab versus those receiving placebo achieved IGA mod 2011 (scalp) (obesity, 21/43 [48.8%] versus 4/40 [10.0%], p = 0.0002; no obesity, 23/46 [50.0%] versus 2/42 [4.8%], p < 0.0001) and PSSI 90 responses (obesity, 27/43 [62.8%] versus 4/40 [10.0%], p < 0.0001; no obesity, 27/46 [58.7%] versus 0/42 [0.0%], p < 0.0001). Treatment effect was also maintained for Scalp Itch-NRS response (p < 0.0001) and mean %CFB in affected SSA (no statistical testing), regardless of obesity status. Results in patients treated with tildrakizumab were similar through Week 52. No new safety signals were identified.
Conclusions: No statistically significant differences in efficacy or safety were observed between patients with and without obesity.
Gov identifier: NCT03897088.
Keywords: Investigator Global Assessment modified 2011 of the scalp (IGA mod 2011 [scalp]) score; Obesity; Plaque psoriasis; Psoriasis Scalp Severity Index (PSSI); Scalp psoriasis; Tildrakizumab.
Psoriasis is a skin and joint disease affecting about 60 million people worldwide. Obesity is more common in people with psoriasis than in those without psoriasis and may make psoriasis harder to treat. Tildrakizumab is one available injectable medication for treating moderate-to-severe plaque psoriasis in adults. This study used information from an already completed clinical trial carried out in the USA and Australia and finished in 2022. The purpose was to see whether obesity changes (1) how well tildrakizumab 100 mg works for the treatment of scalp psoriasis and (2) how safe tildrakizumab is for people with scalp psoriasis. Patients were grouped by body mass index (≥ 30 kg/m2 considered obesity) and assessed for whether their psoriasis improved during treatment with either tildrakizumab or an injection with no treatment in it. The measures of improvement included how severely the skin on the scalp was affected, a scalp psoriasis score that combined how much scalp was affected and how severely the skin was affected, scalp itching, and how much scalp surface area was affected. Safety was measured on the basis of side effects during the treatment period. People with or without obesity who were treated with tildrakizumab had more improvement on all scalp psoriasis tests and were more likely to achieve target scores than those not receiving tildrakizumab. People with and without obesity who were treated with tildrakizumab had similar side effects. In conclusion, tildrakizumab seemed to work well and remain safe in people with scalp psoriasis and obesity.
© 2026. The Author(s).