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Aumolertinib Plus Chemotherapy Improves PFS Over Monotherapy in EGFR/TSG Co-Mutated NSCLC
Adding carboplatin-pemetrexed to aumolertinib extended median progression-free survival by more than three months compared with aumolertinib alone in patients with EGFR-mutated non-small cell lung cancer harboring concomitant tumor suppressor gene mutations (19.78 vs 16.53 months; HR 0.58, 95% CI 0.34–0.97). This is the first prospective phase 3 evidence supporting chemotherapy intensification as a genotype-directed strategy in this molecularly defined subset.
What Was Studied
The ACROSS2 trial investigated whether adding carboplatin-pemetrexed chemotherapy to the third-generation EGFR tyrosine kinase inhibitor aumolertinib would improve outcomes compared with aumolertinib alone in patients whose NSCLC carried both EGFR-activating mutations and co-existing tumor suppressor gene (TSG) mutations. This question is clinically relevant because concomitant TSG alterations are known to attenuate the benefit of EGFR-TKI monotherapy, leaving a significant unmet need in this subgroup.
How It Was Studied
ACROSS2 (NCT04500717) was an open-label, multicenter, randomized phase 3 trial conducted across multiple sites. A total of 126 patients with advanced EGFR-mutated NSCLC and concurrent TSG mutations were enrolled and randomly assigned in roughly equal groups — 62 to aumolertinib combined with carboplatin-pemetrexed and 64 to aumolertinib monotherapy. The primary endpoint was median progression-free survival (PFS), assessed at a median follow-up of 25.3 months. Overall survival data were collected but remained immature at the time of analysis, with only 4% data maturity.
What Was Observed
- Progression-free survival was meaningfully longer with combination therapy. The combination arm achieved a median PFS of 19.78 months versus 16.53 months with monotherapy, representing approximately 42% lower risk of progression or death (HR 0.58, 95% CI 0.34–0.97). Although the confidence interval only narrowly excludes 1.0, the direction and magnitude of effect are consistent across time points.
- Landmark PFS rates reinforced the benefit at multiple time points. At 12, 18, and 24 months, PFS rates favored the combination: 78.7% vs 65.3%, 67.2% vs 40.8%, and 41.0% vs 29.9%, respectively. The 18-month separation — more than 26 percentage points — suggests the combination may be particularly advantageous for sustaining disease control in the intermediate term.
- Patients with co-existing TP53 mutations showed a clear PFS benefit from combination therapy. Subgroup analyses identified TP53 co-mutation as a population where the intensified regimen demonstrated a pronounced advantage, supporting a potential role for TP53 status in refining patient selection within this broader TSG-mutated category.
- Higher-grade toxicity was more frequent with combination therapy but remained manageable. Grade 3 or greater adverse events occurred in 25.9% of patients in the combination arm compared with 17.2% in the monotherapy arm. Critically, no drug-related deaths were reported in either group, suggesting the added toxicity burden is consistent with established profiles for platinum-doublet chemotherapy regimens.
Why This Matters
ACROSS2 provides the first prospective, randomized phase 3 data to challenge the standard monotherapy paradigm for a molecularly defined subset of EGFR-mutated NSCLC. While prior retrospective and exploratory analyses have suggested that TSG co-mutations confer worse outcomes under EGFR-TKI therapy alone, the field has lacked rigorous interventional evidence to guide intensification strategies. This trial establishes a credible proof-of-concept that chemotherapy augmentation directed by genomic stratification can yield measurable improvements in disease control duration.
How to Read This Result
The trial was relatively small (126 patients), the confidence interval around the hazard ratio narrowly crosses statistical significance at its upper bound, and overall survival data remain immature, all of which warrant cautious interpretation of the magnitude and durability of benefit.
Limitations
The abstract does not explicitly report study limitations beyond the immaturity of overall survival data, which had reached only 4% data maturity at the time of analysis. The open-label design and modest sample size may also constrain the generalizability and precision of the findings.