Real-World Data Highlights Class-Based Differences in Psoriasis Biologic Outcomes

The treatment landscape for moderate-to-severe plaque psoriasis has expanded rapidly, but guidance often compares drug classes rather than individual biologics. That makes real-world, head-to-head data valuable for deciding among classes of therapy.

A new post hoc analysis from the international Psoriasis Study of Health Outcomes (PSoHO), published in Advances in Therapy, offers one of the broadest class-level comparisons to date.

The analysis included 1,981 patients across 16 countries, grouping biologics by their immunologic targets:

• IL-17A/IL-17 receptor A inhibitors
• IL-23 inhibitors
• IL-12/23 inhibitors
• Tumor necrosis factor (TNF) inhibitors

The primary outcome was stringent: at least a 90 percent improvement in the Psoriasis Area and Severity Index (PASI90) or a Physician Global Assessment score of clear or almost clear at week 12, month 6, and month 12. Quality of life was assessed using the Dermatology Life Quality Index (DLQI), and durability was measured by the ability to maintain responses through one year.

IL-17 Inhibitors Stand Out

Patients receiving IL-17A/RA inhibitors had the highest likelihood of achieving early and sustained responses. By week 12, they were significantly more likely than other groups to reach PASI90 or clear/almost clear skin, and they retained those gains through month 12. Unadjusted response rates at one year were strong across the board, ranging from about 54 to 69 percent, but IL-17 blockade consistently topped the rankings, except when compared with IL-23 inhibitors at month 12, where the two classes were comparable.

Durability of response further distinguished IL-17 therapies. Patients who responded at week 12 and remained on therapy had 1.4 to 2.6 times greater odds of maintaining those results through one year compared with other classes. The likelihood of maintaining complete clearance (PASI100) or near-complete clearance (PASI90) was also highest with IL-17A/RA inhibitors.

Quality of life results mirrored clinical outcomes. Nearly 40 percent of patients on IL-17 therapies reported a DLQI score of 0 or 1 by week 12—indicating no or minimal impact on daily life. Differences narrowed by month 12, but IL-17 inhibition still provided the most rapid improvements.

Key Considerations and Clinical Takeaways

The analysis looked at drug classes, not individual biologics, which masks variability within each group. Sample sizes varied, with far more patients on IL-17 inhibitors than on IL-12/23 drugs, potentially influencing precision. As with all observational studies, selection bias and unmeasured confounders cannot be excluded.

For patients with moderate-to-severe psoriasis, blocking the IL-17 pathway offered the fastest and most durable responses in this large real-world cohort. IL-23 inhibitors achieved similar outcomes at one year, though with slower onset. For clinicians, these findings reinforce the importance of weighing not only efficacy but also speed of improvement when selecting a biologic class—factors that often matter most to patients in daily practice.

Reference
Khattri S, González-Cantero Á, Engin B, et al. Comparative effectiveness of biologic classes in clinical practice: month 12 outcomes from the international observational Psoriasis Study of Health Outcomes (PSoHO). Adv Ther. 2025;42:233–245. doi:10.1007/s12325-024-03034-1.