CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-23). 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. 1222 · Search date 2026-07-23 · Methodology v0.6

Pembrolizumab,
does it really help with Prevention of recurrence and distant metastasis in completely resected high-risk stage III melanoma?

30-Second Summary
B
Evidence Grade B · 78 · Safety unknown
Adjuvant pembrolizumab durably reduces recurrence and distant metastasis after resection of stage III melanoma, while overall survival remains unestablished
What the
research shows
Adjuvant pembrolizumab is rated B because it reduces recurrence and distant metastasis after complete resection of high-risk stage III melanoma. KEYNOTE-054 double-blindly randomized 1,019 patients to pembrolizumab or placebo and initially found a recurrence-free-survival hazard ratio of 0.57. At seven years, benefits persisted for recurrence-free survival, HR 0.63, and distant-metastasis-free survival, HR 0.64. Overall survival had not been established at the verification point, so strong direct prevention evidence supports B with 78 points.
What the
ads claim
Adjuvant immunotherapy should not be presented as zero recurrence or guaranteed cure. It lowers average recurrence risk, but recurrence still occurs and immune-mediated adverse events are possible.
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Useful facts when choosing a product

  • Pembrolizumab is a prescription intravenous PD-1-blocking immunotherapy used as adjuvant treatment after complete resection of melanoma at high risk of recurrence.
  • Thyroid, liver, and kidney function and symptoms are monitored; new diarrhea, cough, breathlessness, jaundice, or severe fatigue can signal immune-mediated inflammation.
  • Immune-mediated pneumonitis, colitis, hepatitis, nephritis, endocrinopathies, and severe skin reactions can occur, including after treatment has ended.
  • Immune toxicity may require treatment interruption, discontinuation, or corticosteroids, so new symptoms should be reported promptly to the oncology team.
Gap Measurement · Verdict 1222 · B 78
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

KEYNOTE-054 was a double-blind phase 3 trial randomizing 1,019 patients with completely resected high-risk AJCC-7 stage IIIA, IIIB, or IIIC melanoma to pembrolizumab 200 mg every three weeks for up to 18 doses or placebo. The 2018 primary recurrence-free-survival hazard ratio was 0.57. At 3.5 years, distant-metastasis-free survival was 65.3% versus 49.4%, HR 0.60. In 2024, seven-year recurrence-free survival was 50% versus 36%, HR 0.63, and distant-metastasis-free survival was 54% versus 42%, HR 0.64. The B grade follows the clinical endpoints rather than approval status because overall survival is not established.

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Why this is classified as B (78)

A 1,019-participant double-blind placebo-controlled phase 3 trial improved recurrence-free and distant-metastasis-free survival with benefits sustained for seven years. Overall survival remains unestablished and the claim is recurrence prevention, supporting high B with 78 points. Immune toxicity is kept separate under safety.

Counterpoint. Absolute benefit and treatment burden vary with surgical stage, nodal tumor burden, BRAF status, comorbidity, and patient preference.

Rejudgment record. New verdict — The double-blind placebo-controlled KEYNOTE-054 trial demonstrated seven-year durable gains in recurrence-free and distant-metastasis-free survival, but overall survival remains immature, supporting direct recurrence-progression prevention grade B

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
Prolonged recurrence-free survival after complete resection of stage III melanomaBThe placebo-controlled benefit persisted for seven years, but the endpoint is recurrence prevention.
Prevention of distant metastasisBSeven-year distant-metastasis-free survival was 54% versus 42%, with HR 0.64.
Prolonged overall survivalCAn overall-survival benefit was not established at verification, so efficacy is not asserted.

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.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Eggermont AMM et al. 2018 KEYNOTE-054Multicenter double-blind randomized placebo-controlled phase 3 trial1,019Merck Sharp & DohmeRecurrence-free survivalPembrolizumab reduced recurrence or death versus placebo, with HR 0.57.Pivotal molecule-specific placebo-controlled phase 3 evidence
Eggermont AMM et al. 2024 KEYNOTE-054 seven-year analysisLong-term follow-up of the original randomized trial1,019Merck Sharp & DohmeSeven-year recurrence-free and distant-metastasis-free survivalBenefits persisted with seven-year recurrence-free-survival HR 0.63 and distant-metastasis-free-survival HR 0.64.Long-term durability confirmation
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-07-23).

Eggermont AMM, Blank CU, Mandala M, et al. Adjuvant Pembrolizumab versus Placebo in Resected Stage III Melanoma. N Engl J Med. 2018;378(19):1789-1801. PMID: 29658430. DOI: 10.1056/NEJMoa1802357.
checked
Eggermont AMM, Kicinski M, Blank CU, et al. Seven-year analysis of adjuvant pembrolizumab versus placebo in stage III melanoma in the EORTC1325/KEYNOTE-054 trial. Eur J Cancer. 2024;211:114327. PMID: 39288737. DOI: 10.1016/j.ejca.2024.114327.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-23 · Corrections: none

Cite this verdict

Pembrolizumab x prevention of recurrence and distant metastasis after complete resection of stage III melanoma Evidence Grade B card
[Chamgap] Pembrolizumab x prevention of recurrence and distant metastasis after complete resection of stage III melanoma — Evidence Grade B·78. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/pembrolizumab-resected-stage-three-melanoma-recurrence-prevention/ · 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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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.