Clinical Associate Professor, University of Calgary, Councilor for the International Psoriasis Council, as well as Co-Founder and Co-Director of the Skin Health & Wellness Centre, Dermatology Research Institute, and Dermphi Centre

Vimal H. Prajapati, MD

Bridging the Treatment Gap in Pediatric Psoriasis and PsA With Guselkumab, With Vimal H. Prajapati, MD

The U.S. Food and Drug Administration (FDA) has taken a significant step forward in pediatric dermatology and rheumatology with the approval of guselkumab (Tremfya) for children aged 6 years and older who weigh at least 40 kg and have moderate to severe plaque psoriasis (PsO) or active psoriatic arthritis (PsA). This decision, announced September 29, 2025, makes guselkumab the first and only IL-23 inhibitor approved for these pediatric indications, filling an important therapeutic gap for young patients and their families. While several advanced systemic therapies have transformed care for adults with PsO and PsA, treatment options for children have remained limited, often leaving clinicians reliant on older or less effective approaches.

Guselkumab’s approval builds on nearly a decade of research, following its initial FDA authorizations in adults with plaque PsO in 2017 and active PsA in 2020. The agent is a fully human, dual-acting monoclonal antibody that not only blocks IL-23 by binding to its p19 subunit but also binds to CD64, a receptor on IL-23–producing cells at the site of inflammation. In pediatric PsO, approval was based on the phase 3 PROTOSTAR trial, which showed robust efficacy: at week 16, 56% of treated patients achieved PASI 90 compared with 16% on placebo (

<.01), while 40% reached complete clearance versus 4% on placebo (

<.01). For pediatric PsA, evidence from pharmacokinetic extrapolation studies corroborated safety and efficacy findings seen in adults.

 spoke with PROTOSTAR study investigator Vimal H. Prajapati, MD, Clinical Associate Professor, University of Calgary, Councilor for the International Psoriasis Council, as well as Co-Founder and Co-Director of the Skin Health & Wellness Centre, Dermatology Research Institute, and Dermphi Centre, to learn more about the significance of guselkumab’s approval as the first IL-23 inhibitor available for children, the strength of the supporting clinical trial data, and how this milestone may shift treatment strategies for pediatric psoriatic disease.

"[Guselkumab] now being the first approved interleukin 23 inhibitor for plaque psoriasis and psoriatic arthritis in pediatric patients, is a historic moment for the field of dermatology and a milestone that I'm very excited about," Prajapati said.

Prajapati's relevant disclosures include AbbVie, Actelion, Amgen, Arcutis, Boehringer Ingelheim, Bristol Myers Squibb, Celegene, Eli Lilly, GSK, and Janssen.

Brooks A. FDA Approves Guselkumab (Tremfya) for Pediatric Plaque Psoriasis, Psoriatic Arthritis. News article. HCPLive. September 29, 2025. https://www.hcplive.com/view/redefining-severe-airway-disease-care-biologics-barriers

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Prajapati discussed the impact of the expanded approval of guselkumab to pediatric PsO and psoriatic arthritis.

Vimal H. Prajapati, MD

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