Written By: Gayatri Bhor BPharm
Reviewed By: Pharmacally Editorial Team
The U.S. Food and Drug Administration have expanded the label for TREMFYA (Guselkumab), now approving it for children six years of age and older who weigh at least 40 kg for two indications: moderate to severe plaque psoriasis and active psoriatic arthritis. This is the first approval of an IL-23 inhibitor for these pediatric indications and marks an important step for clinicians who treat children with inflammatory skin and joint disease.
About TREMFYA
TREMFYA is a fully human monoclonal antibody that targets interleukin 23. It was initially approved for adult plaque psoriasis in 2017 and later for adult psoriatic arthritis. The pediatric approval applies to patients ≥6 years old who also weigh ≥40 kg, and the labeled pediatric dosing is 100 mg by subcutaneous injection at Week 0, Week 4, then every 8 weeks thereafter. TREMFYA is described by the manufacturer as a dual-acting antibody that blocks IL-23 and binds CD64 on certain IL-23 producing cells; the clinical significance of the CD64 interaction is not established beyond in vitro findings.
About Plaque Psoriasis and Psoriatic Arthritis
Plaque psoriasis is an immune mediated disease that often begins in childhood. Lesions can be itchy, painful and stigmatizing, and up to one third of psoriasis cases start before adulthood. Juvenile psoriatic arthritis is an uncommon form of juvenile idiopathic arthritis characterized by both joint inflammation and psoriatic skin findings. Both conditions can impair physical function, school participation and psychosocial development. Expanding safe and effective treatment options for children was a clear unmet need.
Extended indication and rationale
The approval covers
Moderate to severe plaque psoriasis in children ≥6 years and ≥40 kg who are candidates for systemic therapy or phototherapy
Active psoriatic arthritis in the same pediatric population
For the psoriatic arthritis approval, regulatory reviewers accepted pharmacokinetic extrapolation from adult PsO and PsA studies together with pediatric psoriasis efficacy and safety data. This approach is commonly used when disease biology and drug exposure/response relationships are considered sufficiently similar across age groups.
Clinical Evidence
The PROTOSTAR trial (NCT03451851) was a Phase 3, multicenter, randomized, double-blind, placebo-controlled study evaluating guselkumab (TREMFYA) in pediatric patients with moderate to severe plaque psoriasis. Eligible participants were children aged 6 to less than 18 years, weighing at least 40 kg, who were candidates for systemic therapy or phototherapy. Patients were randomized to receive guselkumab or placebo, with dosing matched to adult regimens (100 mg at Week 0 and Week 4, then every 8 weeks). The co-primary endpoints were the proportion of patients achieving a PASI 90 response and an IGA score of 0 or 1 (clear or almost clear) at Week 16. Secondary endpoints included complete clearance (IGA 0), improvement in quality of life scores, and durability of response through longer-term follow-up.
Results
At Week 16, the trial met both primary endpoints. 56% of Guselkumab-treated children achieved PASI 90 compared with 16% of placebo patients, and 66% achieved IGA 0/1 compared with 16% of placebo. Rates of complete skin clearance (IGA 0) were also higher with Guselkumab (about 40% vs 4%). Improvements were rapid and consistent with efficacy seen in adult psoriasis trials. Safety findings showed Guselkumab was generally well tolerated, with adverse events largely consisting of upper respiratory tract infections and nasopharyngitis, and no new safety concerns identified in this pediatric population. Overall, PROTOSTAR demonstrated that Guselkumab provides robust and clinically significant improvements in skin clearance in children, supporting its FDA approval for pediatric plaque psoriasis.
Safety profile
Short-term safety through Week 16 in PROTOSTAR showed:
- Overall adverse events were reported less frequently in the Guselkumab arm compared with placebo through Week 16 in the trial dataset presented.
- The most common adverse events were Nasopharyngitis, upper respiratory tract infection and COVID-19.
- Important boxed/label warnings are carrying forward to pediatric patients from adult experience: potential for serious allergic reactions and increased risk of infections. Patients should be evaluated for latent tuberculosis before starting therapy.
Longer term pediatric safety data are limited compared with adult experience. The label and company statements note ongoing study and post-marketing monitoring to better define long-term safety in children. Physicians should continue standard monitoring for infections and counsel families about immunization and infection risk.
Implications for Public Health
This approval expands the therapeutic toolkit for pediatric dermatologists and pediatric rheumatologists in several practical ways:
- A new mechanism of action is now available for children: IL-23 selective inhibition. That offers an alternative to TNF inhibitors, IL-17 inhibitors and conventional systemic agents.
- The dosing schedule (induction Week 0 and 4, then every 8 weeks) is convenient and may improve adherence compared with therapies requiring more frequent dosing.
- For children who meet the age and weight criteria and who have significant skin burden or active joint disease, TREMFYA provides a labeled biologic option that demonstrated rapid skin clearance in a controlled trial.
- Because the PsA approval relied in part on PK extrapolation, physicians should be careful about patient selection and follow-up, particularly in younger or lower weight children who do not meet the ≥40 kg inclusion.
Key opinion from the J&J press release
Experts and stakeholders welcomed the FDA’s pediatric approval of TREMFYA. Dr. Vimal Prajapati, a study investigator, noted that the therapy offers physicians, parents, and children a proven and effective option to manage the signs and symptoms of psoriasis and psoriatic arthritis. From Johnson & Johnson, Brandee Pappalardo emphasized that this is the first pediatric approval for an IL-23 inhibitor, calling it an important step for children and their caregivers, while reaffirming the company’s commitment to long-term safety and efficacy research. Leah Howard of the National Psoriasis Foundation highlighted the hope this approval brings for children and families dealing with the physical and emotional burden of these diseases.
The FDA’s decision to approve TREMFYA for children ≥6 years old who weigh ≥40 kg with moderate to severe plaque psoriasis or active psoriatic arthritis offers a new, evidence-backed option for physicians for treating pediatric immune-mediated skin and joint disease. The PROTOSTAR trial showed robust skin clearance by Week 16 and the PsA approval was supported by pharmacokinetic extrapolation plus adult PsA data.
References
U.S. FDA approves TREMFYA® (guselkumab) for the treatment of pediatric plaque psoriasis and active psoriatic arthritis, marking a first and only approval for an IL-23 inhibitor, J&J, 29 September 2025, https://www.jnj.com/media-center/press-releases/u-s-fda-approves-tremfya-guselkumab-for-the-treatment-of-pediatric-plaque-psoriasis-and-active-psoriatic-arthritis-marking-a-first-and-only-approval-for-an-il-23-inhibitor
Highlights of prescribing information, TREMFYA® (guselkumab) injection, for subcutaneous or intravenous use, (updated version), https://www.janssenlabels.com/package-insert/product-monograph/prescribing-information/TREMFYA-pi.pdf
Prajapati VH, Seyger MMB, Wilsmann-Theis D, et al, Guselkumab for the treatment of moderate-to-severe plaque psoriasis in paediatric patients: results of the phase III randomized placebo-controlled PROTOSTAR study. Br J Dermatol. 2025 Mar 18;192(4):618-628. Doi:10.1093/bjd/ljae502. PMID: 39708367