Real-Life Evaluation of Guselkumab Dosing Interval Adjustments

Real-Life Evaluation of Guselkumab Dosing Interval Adjustments. SPAcing-GUS

"Guselkumab (Tremfya®) is a fully human monoclonal antibody that selectively targets interleukin-23 (IL-23), a key cytokine involved in the inflammatory pathways of psoriasis. This biologic therapy received marketing authorization in France in 2018 for the treatment of moderate-to-severe plaque psoriasis in adults requiring systemic therapy. This indication includes patients with extensive disease, with or without significant psychosocial impact, and those who have had an inadequate response, contraindication, or intolerance to at least two conventional systemic non-biologic treatments (such as methotrexate, ciclosporin, or acitretin) or phototherapy. The GUIDE study demonstrated that guselkumab injection intervals may be extended in psoriasis "super-responders" (defined as PASI 0 at Weeks 20 and 28). In this study, dosing intervals were extended from 8 to 16 weeks starting at Week 28 without waiting for prolonged confirmation of complete response. While the primary endpoint (maintenance of PASI <3 at Week 64) showed non-inferiority between the q8 and q16 groups, patients receiving injections every 16 weeks experienced a significantly greater loss of PASI 0 and PASI 1 responses at Week 64. This was associated with a reduction in quality of life (measured by DLQI) in the 16-week group compared with the 8-week group. Nevertheless, GUIDE highlights the flexibility of guselkumab administration, particularly in super-responders at Week 28.

Guselkumab (Tremfya®) is a biologic treatment used for moderate to severe psoriasis. It works by blocking a molecule involved in inflammation and has been approved in France since 2018. The standard dosing schedule is one injection every 8 weeks after the initial treatment phase.

A clinical study (GUIDE) showed that in some patients who respond extremely well to treatment ("super responders"), it may be possible to space the injections further apart. However, extending injections to every 16 weeks slightly reduced the chance of maintaining complete skin clearance in some patients. In real-life practice, many dermatology centers gradually increase the time between injections once patients achieve stable and almost complete clearance of their psoriasis. The approach varies between centers.

Using large French healthcare databases, we studied how guselkumab is used in routine practice. We found that about 38% of patients spaced their injections beyond the recommended 8 weeks, and this proportion increased to 47% in patients treated for more than 2 years. Importantly, spacing injections did not reduce how long patients stayed on treatment. Among patients who stopped guselkumab after spacing their doses, most did not need another systemic treatment for at least one year, suggesting that some patients may benefit from temporary "treatment breaks." These results suggest that for certain patients with well-controlled psoriasis, guselkumab dosing may be safely adjusted, offering greater flexibility, reduced treatment burden, and potentially lower healthcare costs."

Study Overview

• Status: Recruiting
• Conditions: Psoriasis
• Intervention / Treatment: Drug: Guselkumab (Tremfya®)

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Thierry PASSERON; Phone Number: +33 0492036225; Email: passeron.t@chu-nice.fr
• Study Contact Backup: Name: Ruxanda MOSCHOI; Phone Number: +33 0492033993; Email: moschoi.r@chu-nice.fr

Study Locations

• France
  • Alpes Maritimes
    • Nice, Alpes Maritimes, France, 06000
      • Recruiting
      • CHU de Nice
      • Contact: Thierry PASSERON; Phone Number: +33 0492036225; Email: passeron.t@chu-nice.fr
      • Contact: Ruxanda MOSCHOI; Phone Number: +33 0492033993; Email: moschoi.r@chu-nice.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

Eligible patients diagnosed with cutaneous psoriasis treated with guselkumab, for whom a dosing interval extension was proposed

Description

Inclusion Criteria:

• .Adult patients receiving guselkumab for cutaneous psoriasis. 2.
• Guselkumab treatment with dosing intervals exceeding 9 weeks.

Exclusion Criteria:

• Patients receiving guselkumab primarily for joint involvement.
• Patients for whom guselkumab dosing was extended due to surgery, pregnancy, or infection.
• Patients for whom the PASI or IGA score was not assessed during visits

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Patients diagnosed with cutaneous psoriasis; Treated with guselkumab for whom dose spacing has been proposed.

Drug: Guselkumab (Tremfya®); Guselkumab (Tremfya®) is a fully human monoclonal antibody that selectively targets the p19 subunit of interleukin-23 (IL-23), a key cytokine involved in the inflammatory pathway of psoriasis. By inhibiting IL-23, guselkumab reduces downstream inflammatory signaling and improves psoriatic skin lesions. The aprouved dosing regimen: 100 mg administered by subcutaneous injection at Week 0 and Week 4 (induction phase),; followed by 100 mg every 8 weeks thereafter (maintenance phase).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the modalities of guselkumab dose spacing	PASI Score ( Psoriasis Area and Severity Index )	At the inclusion
Psoriasis severity	PASI Score ( Psoriasis Area and Severity Index )	At the inclusion
Duration of guselkumab treatment prior to dose spacing	In weeks	At the inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of patient characteristics in individuals undergoing Dose spacing	PASI Score Psoriasis Area and Severity or IGA score Investigator Global Assessment graded on a scale from 0 to 4	At the inclusion
Evaluation of Guselkumab Treatment Persistence During Dose Spacing	PASI Score Psoriasis Area and Severity or IGA score score Investigator Global Assessment graded on a scale from 0 to 4	At the inclusion

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nice

Study record dates

Study Major Dates

• Study Start (Actual): October 16, 2025
• Primary Completion (Estimated): April 16, 2026
• Study Completion (Estimated): April 16, 2026

Study Registration Dates

• First Submitted: February 18, 2026
• First Submitted That Met QC Criteria: February 18, 2026
• First Posted (Actual): February 24, 2026

Study Record Updates

• Last Update Posted (Actual): February 24, 2026
• Last Update Submitted That Met QC Criteria: February 18, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases, Papulosquamous; Skin Diseases; Skin and Connective Tissue Diseases; Psoriasis; guselkumab
• Other Study ID Numbers: 26Dermato01

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No