FDA approves guselkumab for the treatment of pediatric plaque psoriasis and active psoriatic arthritis

On September 30, 2025, the U.S. Food and Drug Administration (FDA) approved the IL-23 inhibitor guselkumab for the treatment of pediatric patients with moderate-to-severe plaque psoriasis, who are candidates for systemic therapy or phototherapy, or with active psoriatic arthritis, aged ≥6 years, and weighing ≥40 kg.^1,2

The approval was based on findings from the phase III PROTOSTAR trial (NCT03451851), which evaluated the efficacy and safety of guselkumab in pediatric patients aged ≥6 to <18 years with chronic moderate-to-severe plaque psoriasis (N = 120).^1,2  

The co-primary endpoints were Investigator Global Assessment (IGA) 0/1 and ≥75% improvement in Psoriasis Area and Severity Index (PASI 75) (or FDA-required ≥90% improvement in PASI [PASI 90] co-primary endpoint) responses at Week 16 of Part 1 of the trial. Part 2 evaluated continuous open-label guselkumab treatment (Week 0 to Week 52).^1,2

• In Part 1, more patients treated with guselkumab vs placebo achieved IGA 0/1 (66% vs 16%; p < 0.001), PASI 75 (76% vs 20%; p < 0.001) and PASI 90 (56% vs 16%; p < 0.01) at Week 16.²
• Over a third of patients who received guselkumab achieved skin clearance (IGA 0: 39% vs 4% placebo; 100% improvement in PASI (PASI 100): 34% vs 0% placebo; both p < 0.01].²
• In Part 2, 86%, 93%, and 82% of patients treated with guselkumab achieved IGA 0/1, PASI 75, and PASI 90, respectively, at Week 52.²
• Safety outcomes for guselkumab were similar to placebo and were consistent with the established safety profile in adults.²

This approval marks the first approval of an IL-23 inhibitor for these pediatric indications and follows FDA approvals of guselkumab for the treatment of adults with moderate-to-severe plaque PsO in 2017 and active PsA in 2020.¹