The Absolute Effect / Oncology Evidence / Evidence Index
MARIPOSA
In untreated EGFR-mutated advanced NSCLC, does amivantamab plus lazertinib improve progression-free survival over osimertinib?
Registry: NCT04487080 · Evidence reviewed 9 November 2026 · Aliases and follow-up publications consolidated.
Phase III randomized 2:2:1; n=1,074.Primary-source evidence summaryStudy design, population and eligibility
Phase III randomized 2:2:1; n=1,074.
Untreated advanced NSCLC with EGFR exon19del/L858R.
Treatment and comparator
Intervention: Amivantamab + lazertinib.
Comparator: Osimertinib; lazertinib-alone third arm.
Endpoints
PFS by BICR primary.
Key efficacy and clinical outcomes
Median PFS 23.7 vs 16.6 mo (HR 0.70); ORR 86% vs 85%; interim OS HR 0.80 (0.61–1.05).
Source-reported outcome visualization
Values are reproduced from the cited report; bars are scaled within this figure. First-line EGFR-mutated advanced NSCLC
Median survival and hazard ratios are not fixed-time event risks; NNT is not inferred from them.
Toxicity and treatment burden
EGFR toxicities, infusion reactions, rash, paronychia and VTE; discontinuation of all agents for treatment-related AEs 10% vs 3%.
Absolute effect and NNT/NNH
PFS superiority established; interim OS not significant. Greater treatment burden than oral osimertinib.
NNT/NNH is not calculated unless a directly reported, comparable fixed-time risk difference supports it. Median survival and hazard ratios alone do not provide an NNT.
Critical interpretation and limitations
PFS superiority established; interim OS not significant. Greater treatment burden than oral osimertinib.
This page is an evidence summary, not a substitute for multidisciplinary assessment or patient-specific decision-making.
Current-practice context
Review date: 9 November 2026. Primary publication and selected follow-up sources were reviewed. Full disease-specific guideline, regulatory-label and sequencing audit remains pending; verify current local recommendations and biomarker eligibility before clinical application.