CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-24). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1815 · Search date 2026-07-24 · Methodology v0.6

Guselkumab,
does it really help with PASI90 and IGA 0 or 1 skin-lesion response in moderate-to-severe plaque psoriasis?

30-Second Summary
C
Evidence Grade C · 58 · Safety caution
Week-16 skin responses were very large, but confirmatory evidence remains manufacturer-sponsored and surrogate-based
Infections, injection-site reactions, and headache can occur. Screening for infections such as tuberculosis and avoidance of live vaccines are needed; suspected serious infection or hypersensitivity requires prompt medical assessment.
What the
research shows
Guselkumab is rated C for plaque-psoriasis skin clearance. VOYAGE 1 randomized and analyzed 837 participants by intention to treat. At week 16, coprimary IGA 0 or 1 response was 85.1% versus 6.9% with placebo, and PASI90 was 73.3% versus 2.9%; both succeeded at P<0.001. VOYAGE 2 reproduced the result in 992 intention-to-treat participants, at 84.1% versus 8.5% and 70.0% versus 2.4%. Effects were very large, but the confirmatory coprimary outcomes were PASI and IGA lesion-score surrogates, S, and both trials belonged to the Janssen development program, I0. Each feature independently caps the grade at C.
What the
ads claim
Marketing can expand high PASI90 and IGA response into a permanent cure or prevention of every long-term complication. Strong 16-week skin response is true; permanent remission, cardiovascular-event prevention, and cure go beyond that evidence.
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Useful facts when choosing a product

  • Guselkumab is a subcutaneous monoclonal antibody targeting the p19 subunit of IL-23. VOYAGE used 100 mg at weeks 0 and 4 and every eight weeks thereafter.
  • verdict 1814, which is C with 58 points, asks whether home narrowband UV-B is noninferior to office phototherapy; this verdict asks about placebo-controlled efficacy of a biologic drug.
  • verdict 1342, which is B with 76 points, concerns secukinumab, while verdict 1796, which is C with 55 points, concerns deucravacitinib. The same surrogate logic applied to PASI and static PGA in verdict 1796 is applied to PASI and IGA here.
Gap Measurement · Verdict 1815 · C 58
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Blauvelt's VOYAGE 1 assigned 837 participants to guselkumab, 329, placebo, 174, or adalimumab, 334, and analyzed all 837 by intention to treat. At week 16, coprimary IGA 0 or 1 was 85.1% versus 6.9%, and PASI90 was 73.3% versus 2.9%, both P<0.001. Reich's VOYAGE 2 assigned 992 to guselkumab, 496, placebo, 248, or adalimumab, 248, and analyzed all 992. The same coprimary outcomes were 84.1% versus 8.5% and 70.0% versus 2.4%, both P<0.001. Janssen Research & Development sponsored both trials and participated in design and analysis.

02

Why this is classified as C (58)

The profile is S, R1, I0, E+, and B0. Both large primary endpoints succeeded, but the same Janssen development program is not independent replication, and the R1, surrogate, and manufacturer-only ceilings produce C with 58 points.

Counterpoint. Patient-reported itch and quality-of-life benefits were also reported, but PASI and IGA were the confirmatory coprimary endpoints. Secondary patient-reported outcomes do not change the representative axis to P.

Rejudgment record. Cross-check applied — Accepted large successful intention-to-treat effects in VOYAGE 1 and 2 while consistently applying C ceilings for PASI and IGA surrogates and Janssen-only evidence

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI0Evidence comes only from manufacturer studies
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (C).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Achievement of PASI90 at week 16CTwo large manufacturer trials repeatedly succeeded, but PASI90 is a surrogate.
Achievement of IGA 0 or 1 at week 16CBoth coprimary endpoints were strongly positive, but evidence is manufacturer-only.
Achievement of complete skin clearance with PASI100CA large effect occurred on this secondary lesion scale, but the same S and I0 ceilings apply.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Blauvelt A et al. 2017 VOYAGE 1Phase 3 double-blind randomized placebo- and active-controlled trial837Manufacturer sponsorship, design, and analysis by Janssen Research & DevelopmentCoprimary week-16 IGA 0 or 1 and PASI9085.1% versus 6.9% and 73.3% versus 2.9%, both P<0.001; both coprimary endpoints met.Pivotal manufacturer confirmatory trial
Reich K et al. 2017 VOYAGE 2Phase 3 double-blind randomized placebo- and active-controlled withdrawal and retreatment trial992Manufacturer sponsorship, design, and analysis by Janssen Research & DevelopmentCoprimary week-16 IGA 0 or 1 and PASI9084.1% versus 8.5% and 70.0% versus 2.4%, both P<0.001; both coprimary endpoints met.Large replication within the same manufacturer program
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-07-24).

Blauvelt A, Papp KA, Griffiths CEM, et al. Efficacy and safety of guselkumab, an anti-interleukin-23 monoclonal antibody, compared with adalimumab for the continuous treatment of patients with moderate to severe psoriasis: Results from the phase III, double-blinded, placebo- and active comparator-controlled VOYAGE 1 trial. J Am Acad Dermatol. 2017;76(3):405-417. PMID: 28057360. DOI: 10.1016/j.jaad.2016.11.041.
checked
Reich K, Armstrong AW, Foley P, et al. Efficacy and safety of guselkumab, an anti-interleukin-23 monoclonal antibody, compared with adalimumab for the treatment of patients with moderate to severe psoriasis with randomized withdrawal and retreatment: Results from the phase III, double-blind, placebo- and active comparator-controlled VOYAGE 2 trial. J Am Acad Dermatol. 2017;76(3):418-431. PMID: 28057361. DOI: 10.1016/j.jaad.2016.11.042.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-24 · Corrections: none

Cite this verdict

Guselkumab x skin clearance in moderate-to-severe plaque psoriasis Evidence Grade C card
[Chamgap] Guselkumab x skin clearance in moderate-to-severe plaque psoriasis — Evidence Grade C·58. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/guselkumab-plaque-psoriasis-skin-clearance/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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