A Study of Guselkumab Given After Ustekinumab in Participants With Moderate to Severe Psoriasis in Routine Clinical Practice (G-START)

A Non-Interventional, Multi-Centric, Single Country Observational Study to Assess the Safety and Effectiveness of Guselkumab After Ustekinumab (Originator or Biosimilar) in Moderate to Severe Psoriasis Patients in Clinical Routine

The main purpose of this study is to describe how well Guselkumab works after switching from Ustekinumab in participants with moderate to severe psoriasis in a routine clinical setting. A long-term skin disease that causes red, scaly and sometimes painful, itchy patches on the skin.

Study Overview

• Status: Recruiting
• Conditions: Psoriasis

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

Contacts and Locations

• Study Contact: Name: Study Contact; Phone Number: 844-434-4210; Email: Participate-In-This-Study1@its.jnj.com

Study Locations

• Hungary
  • Budapest, Hungary, 1088
    • Recruiting
    • Semmelweis University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants with moderate-to-severe psoriasis who are candidates for systemic treatment (according to the Guselkumab label) and who are medically indicated to switch from Ustekinumab or its biosimilar to Guselkumab can be included in this study.

Description

Inclusion criteria:

• Must have a confirmed diagnosis of moderate-to-severe plaque psoriasis requiring systemic treatment
• Participants who are currently being treated with Ustekinumab (either the originator or its biosimilar) and who are medically indicated to switch to Guselkumab, or for whom this switch is medically indicated, based on the current and valid national psoriasis (PsO) therapeutic protocol
• Participants who, based on the Investigator's decision, should initiate treatment with Guselkumab
• Participants must sign an informed consent form (ICF) allowing for data collection and source data verification in accordance with local requirements

Exclusion criteria:

• Contraindication or hypersensitivity to Guselkumab or any other ingredient in the injection solution
• Pregnancy or breastfeeding
• Currently enrolled in an interventional study
• Currently enrolled in an observational study sponsored or managed by a Janssen company
• Previous use of guselkumab in any indication in participant history

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Moderate to Severe Psoriasis: Guselkumab Switching From Ustekinumab; Participants with moderate-to-severe psoriasis who are candidates for systemic treatment (according to the guselkumab label) and who are medically indicated to switch from Ustekinumab or its biosimilar to receive Guselkumab in routine clinical practice will be enrolled. No drug will be provided as a part of this study. Only data available from routine clinical practice will be collected.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving Absolute Psoriasis Area Severity Index (aPASI) <=3 at Week 20 Following Switch from Ustekinumab to Guselkumab	Percentage of participants achieving aPASI less than or equal to (<=) 3 at Week 20 following the switch from Ustekinumab to Guselkumab will be reported. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	At Week 20

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving aPASI <= 3 at Weeks 4, 12, 36 and 52	Percentage of participants achieving aPASI <= 3 will be reported. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	At Weeks 4, 12, 36 and 52
Percentage of Participants Achieving >= 75% Improvement in PASI (PASI 75) at Weeks 4, 12, 20, 36 and 52	Participants with an absolute percentage improvement of at least 75% will be considered having achieved PASI 75 at Weeks 4, 12, 20, 36 and 52. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	At Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving >= 90% Improvement in PASI (PASI 90) at Weeks 4, 12, 20, 36, and 52	Participants with an absolute percentage improvement of at least 90% will be considered having achieved PASI 90 at Weeks 4, 12, 20, 36 and 52. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	At Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving 100% Improvement in PASI (PASI 100) at Weeks 4, 12, 20, 36, and 52	Participants with an absolute percentage improvement of 100% will be considered having achieved PASI 100 at Weeks 4, 12, 20, 36 and 52. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	At Weeks 4, 12, 20, 36 and 52
Absolute Changes in PASI Score from Baseline up to Weeks 4, 12, 20, 36 and 52	Absolute changes in PASI scores from baseline to Weeks 4, 12, 20, 36 and 52 will be reported. PASI is a widely used measurement tool used to assess the severity of psoriasis. The PASI produces a numeric score that can range from 0 (no psoriasis) to 72. A higher score indicates more severe disease.	Baseline up to Weeks 4, 12, 20, 36 and 52
Absolute Changes in Body Surface Area (BSA) Score from Baseline up to Weeks 4, 12, 20, 36 and 52	Absolute changes in BSA scores from baseline upto Weeks 4, 12, 20, 36 and 52 will be reported. BSA indicates the percentage of the total body surface area affected by psoriasis. For small-spotted psoriasis lesions, healthy skin between the lesions is not included in the assessment. BSA ranges from 0-100 in which the maximum value is 100.	Baseline up to Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving Dermatology Life Quality Index (DLQI) <=5 at Weeks 4, 12, 20, 36 and 52	DLQI is a 10-item instrument questionnaire designed to assess the impact of the disease on a participant's quality of life. Each question is evaluated on a 4-point scale ranged from 0 (not at all) to 3 (very much); where higher scores indicate more impact on quality of life. Scores from all 10 questions are added up to give DLQI total score range from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	At Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving Dermatology Life Quality Index Relevant (DLQI-R) <=5 at Weeks 4, 12, 20, 36 and 52	The DLQI-R is calculated by summing the scores of all answered items on the 10-question DLQI questionnaire (each scored 0-3), excluding those marked as "not relevant" (NRR). The total DLQI-R score ranges from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	At Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving DLQI Score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	DLQI is a 10-item instrument questionnaire designed to assess the impact of the disease on a participant's quality of life. Each question is evaluated on a 4-point scale ranged from 0 (not at all) to 3 (very much); where higher scores indicate more impact on quality of life. Scores from all 10 questions are added up to give DLQI total score range from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	At Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving DLQI-R score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	The DLQI-R is calculated by summing the scores of all answered items on the 10-question DLQI questionnaire (each scored 0-3), excluding those marked as "not relevant" (NRR). The total DLQI-R score ranges from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	At Weeks 4, 12, 20, 36 and 52
Absolute Changes in DLQI Scores from Baseline up to Weeks 4, 12, 20, 36 and 52	Absolute changes in DLQI scores from baseline to Week 4, 12, 20, 36 and 52 will be reported. DLQI is a 10-item instrument questionnaire designed to assess the impact of the disease on a participant's quality of life. The total DLQI score ranges from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	Baseline up to Weeks 4, 12, 20, 36 and 52
Absolute Changes in DLQI-R Scores from Baseline up to Weeks 4, 12, 20, 36 and 52	Absolute changes in DLQI-R scores from baseline to Week 4, 12, 20, 36 and 52 will be reported. The DLQI-R is calculated by summing the scores of all answered items on the 10-question DLQI questionnaire (each scored 0-3), excluding those marked as "not relevant" (NRR). The total DLQI-R score ranges from 0 (not at all) to 30 (very much). Higher scores indicate more impact on quality of life of participants.	Baseline up to Weeks 4, 12, 20, 36 and 52
Absolute Change in Static Physician's Global Assessment of Genitalia (sPGA-G) Score Over Time	In participants with anogenital psoriasis at baseline, absolute change in sPGA-G score over time will be reported. The sPGA-G describes the severity of psoriasis using 6 categories. Accordingly, the score ranges from 0-5, with higher scores indicating more severe psoriasis.	Baseline up to Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving sPGA-G Score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	In participants with anogenital psoriasis at baseline, the percentage of participants achieving sPGA-G score of 0 or 1 amongst the participants who had a >= 2 sPGA-G score at baseline will be reported. The sPGA-G describes the severity of psoriasis using 6 categories. Accordingly, the score ranges from 0-5, with higher scores indicating more severe psoriasis.	At Weeks 4, 12, 20, 36 and 52
Absolute Change in Physician´s Global Assessment of Hands and/or Feet (hf-PGA) Score Over Time	In participants with palmoplantar psoriasis at baseline, absolute change in hf-PGA score over time will be reported. The hf-PGA describes the severity of psoriasis using 5 categories. Accordingly, the score ranges from 0-4, with higher scores indicating more severe psoriasis.	Baseline up to Weeks 4, 12, 20, 36 and 52
Percentage of Participants Achieving hf-PGA Score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	In participants with palmoplantar psoriasis at baseline, percentage of participants achieving hf-PGA = 0 or 1 amongst the participants who had a >= 2 hf-PGA at baseline will be reported. The hf-PGA describes the severity of psoriasis using 5 categories. Accordingly, the score ranges from 0-4, with higher scores indicating more severe psoriasis.	At Weeks 4, 12, 20, 36 and 52
Absolute Change in Scalp-Specific Investigator Global Assessment (ss-IGA) Score Over Time	In participants with scalp psoriasis at baseline, the absolute change in ss-IGA score over time will be reported. The ss-IGA describes the severity of psoriasis using 5 categories. Accordingly, the score ranges from 0-4, with higher scores indicating more severe psoriasis.	Baseline up to Weeks 4, 12, 20, 36, and 52
Percentage of Participants Achieving ss-IGA Score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	In participants with scalp psoriasis at baseline, the percentage of participants achieving ss-IGA of 0 or 1 amongst the participants who had a >= 2 ss-IGA score at baseline will be reported. The ss-IGA describes the severity of psoriasis using 5 categories. Accordingly, the score ranges from 0-4, with higher scores indicating more severe psoriasis.	At Weeks 4, 12, 20, 36, and 52
Absolute Change in Fingernail Physician's Global Assessment (PGA-F) Score Over Time	In participants with fingernail psoriasis at baseline, absolute change in PGA-F score over time will be reported. The PGA-F describes the severity of psoriasis using 5 categories and consists of scores ranging from 0 (Clear), 1 (Minimal), 2 (Mild), 3 (Moderate), 4 (Severe). Here, higher scores indicate more severity of psoriasis.	Baseline up to Weeks 4, 12, 20, 36, and 52
Percentage of Participants Achieving PGA-F Score of 0 or 1 at Weeks 4, 12, 20, 36 and 52	In participants with fingernail psoriasis at baseline, the percentage of participants achieving PGA-F score of 0 or 1 amongst participants who had a >=2 PGA-F at baseline will be reported. The PGA-F describes the severity of psoriasis using 5 categories and consists of scores ranging from 0 (Clear), 1 (Minimal), 2 (Mild), 3 (Moderate), 4 (Severe). Here, higher scores indicate more severity of psoriasis.	At Weeks 4, 12, 20, 36, and 52
Demographic Characteristics: Age	Participant's age at the time of starting guselkumab treatment will be reported.	At Baseline
Demographic Characteristics: Sex	Sex (male, female) of participants at the time of starting guselkumab treatment will be reported.	At Baseline
Demographic Characteristics: Weight	Weight of participants at the time of starting guselkumab treatment will be reported.	At Baseline
Demographic Characteristics: Height	Height of participants at the time of starting guselkumab treatment will be reported.	At Baseline
Clinical Characteristics: Time Since Psoriasis Diagnosis	Time since psoriasis diagnosis (years), in participants starting guselkumab treatment will be reported.	At Baseline
Clinical Characteristics: Time Since First Symptoms	Time since first symptoms (years), in participants starting guselkumab treatment will be reported.	At Baseline
Clinical Characteristics: Severity of Psoriasis	Severity of psoriasis (mild, moderate, severe) in participants starting guselkumab treatment will be reported.	At Baseline
Clinical Characteristics: Affected Areas	Affected areas (anogenital, nail, scalp, palmoplantar), in participants starting guselkumab treatment will be reported.	At Baseline
Clinical Characteristics: Prior and Baseline Treatments for Moderate to Severe Psoriasis	Prior and baseline treatments for moderate-to-severe psoriasis, including start and stop dates (in years) in participants starting guselkumab treatment will be reported.	At Baseline
Number of Participants Switching from Ustekinumab or Biosimilars to Guselkumab	Participants switching treatment and reason for switching treatment from Ustekinumab or biosimilars to Guselkumab will be reported.	At Baseline
Reason for Guselkumab Discontinuation	Number of participants discontinuing guselkumab and reason for guselkumab discontinuation if happens during the study will be reported.	Up to Week 52
Number of Participants with Specific Psoriatic Comorbidities	Specific psoriatic comorbidities at baseline will be reported.	At Baseline
Number of Participants with Adverse Events (AE)	An AE is any untoward medical occurrence in a participant administered with a pharmaceutical product. An AE does not necessarily have a causal relationship with the treatment.	Up to Week 52

Collaborators and Investigators

• Sponsor: Janssen-Cilag Kft.
• Investigators: Study Director: Janssen-Cilag Kft. Clinical Trial, Janssen-Cilag Kft.

Study record dates

Study Major Dates

• Study Start (Estimated): September 15, 2026
• Primary Completion (Estimated): January 30, 2029
• Study Completion (Estimated): March 15, 2029

Study Registration Dates

• First Submitted: July 29, 2026
• First Submitted That Met QC Criteria: August 4, 2026
• First Posted (Actual): August 5, 2026

Study Record Updates

• Last Update Posted (Actual): August 28, 2026
• Last Update Submitted That Met QC Criteria: August 27, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases, Papulosquamous; Skin Diseases; Skin and Connective Tissue Diseases; Psoriasis
• Other Study ID Numbers: CNTO1959PSO4038 (Other Identifier: Janssen Research & Development, LLC)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data sharing policy of Johnson & Johnson Innovative Medicine is available at www.jnj.com/innovativemedicine/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu

Drug and device information, study documents

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