Ustekinumab and IL-23 inhibitors show the lowest overall infection risk among biologics for psoriasis, a cohort study of nearly 40,000 patients has found.

French researchers analysed both inpatient and outpatient-managed infection risks for 39,669 patients with psoriasis who were new biologic users. Overall infection risk was low: 27.1 hospitalised infections per 1,000 person-years with a median of 5.5% of days covered by anti-infectives.

The two-year study compared biologics on three outcomes: time to hospitalisation for infection, time to first outpatient anti-infective dispensation, and proportion of days covered by anti-infectives.

Compared with adalimumab, the most common biologic, the study found:

• Hospitalisation risk for infection was lower with ustekinumab (weighted HR 0.75), secukinumab (wHR 0.72), and risankizumab (wHR 0.57)
• Certolizumab users had a higher risk of antibacterial use (wHR 1.19)
• Ustekinumab, guselkumab and risankizumab showed lower risk of first antibacterial use
• For mycotic infections, IL-17 inhibitors showed higher risk while ustekinumab showed lower risk

Outpatient infection patterns revealed
The researchers noted previous studies had shown conflicting infection risk findings, with many unable to evaluate IL-23 inhibitors due to limited data.

“Outpatient-managed infection risk was low across all biologic groups, with the median proportion of days covered by systemic anti-infectives during biologic exposure similar to that observed before biologics initiation,” the authors wrote in Journal of the American Academy of Dermatology [link here].

The data showed certolizumab may increase bacterial infection, while IL-17 inhibitor biologics may elevate fungal infection risk.

However, the authors noted: “Our results provide rigorous insights into the risk of outpatient-managed infection under biologics, supporting the notion that most biologics used for psoriasis do not induce significant immunosuppression.”

While infliximab showed an apparent increase in hospitalisation for infection, this finding was not statistically significant, though it aligned with previous research.

Overall, ustekinumab and IL-23 inhibitors (guselkumab, risankizumab, tildrakizumab) showed the lowest combined risk, measuring time to first hospitalisation or outpatient infection.

The authors acknowledged limitations including the lack of outpatient diagnosis information in the French National Health Data System and called for further confirmatory studies to address potential biases.