Biologic Efficacy by BMI in Moderate-To-Severe Psoriasis: A Real-World Cohort Study

Obesity reduces response to biologic therapy in psoriasis, but comparative evidence across drug classes in Chinese patients is limited. A real-world cohort of 891 adults with moderate-to-severe psoriasis initiating biologics between 2020 and 2025 was divided by baseline BMI (< 24 vs. ≥ 24 kg/m²). PASI90 achievement at 2, 4, 6 and 12 months and drug survival were compared amongst IL-17, IL-23 and TNF-α inhibitors. Amongst IL-17 users, PASI90 rates in the non-overweight group were consistently higher at 4, 6 and 12 months (all p < 0.05), whereas no BMI-related differences were seen with TNF-α or IL-23 blockade. Within the non-overweight stratum, IL-17 and IL-23 agents outperformed TNF-α inhibitors at month 6 and yielded fewer switches (p < 0.05). In the overweight/obese stratum, IL-23 blockade achieved the highest PASI90 rates and longest drug survival versus both IL-17 and TNF-α inhibitors (p < 0.05). In this real-world cohort of Chinese psoriasis patients, BMI was observed to correlate with biologic effectiveness in a drug-specific manner. Our findings suggest that whilst IL-17 or IL-23 inhibitors showed favourable outcomes for non-overweight individuals, IL-23 blockade may be associated with a more sustained response in those categorised as overweight or obese.