A brief report on stable disease among amivantamab-treated patients with post-platinum epidermal growth factor receptor exon 20 insertion-mutated non-small cell lung cancer: A response-based analysis from the CHRYSALIS study.

BACKGROUND: Amivantamab, an EGFR-MET bispecific antibody, is the first approved targeted therapy for patients with EGFR Ex20ins NSCLC after prior platinum-based chemotherapy-a population with historically poor outcomes before amivantamab approval. As antitumor activity in single-arm studies typically focuses on responders, the evaluation of outcomes in patients with stable disease (SD) as best response is of clinical interest. PATIENTS AND METHODS: Among 114 patients with post-platinum EGFR Ex20ins NSCLC in CHRYSALIS (NCT02609776; data cutoff: March 30, 2021), response was assessed by blinded independent central review via RECIST v1.1. Patients alive and receiving therapy at 12 weeks were grouped by response at this landmark: partial or complete response (PR+), SD, or progressive disease (PD). Progression-free survival (PFS) and overall survival (OS) by response cohort were determined using the Kaplan-Meier method; hazard ratios (HRs) and 95% confidence intervals (CIs) between response cohorts were calculated using Cox proportional hazards regression. RESULTS: Among patients alive and receiving therapy at 12 weeks (n=107), 42 (39%) had PR+, 52 (49%) had SD, and 13 (12%) had PD. Among patients with PR+ and SD, median PFS was 12.2 and 7.0 months, respectively. A corresponding improvement in OS was observed in patients achieving PR+ (median: not reached; HR vs PD=0.21 [95% CI: 0.08-0.54]) and SD (median: 23.0 months; HR vs PD=0.33 [95% CI: 0.14-0.77]), relative to those with PD (median: 14.0 months). CONCLUSION: SD was observed in 49% of patients receiving amivantamab, with corresponding increases in OS that dramatically improved the prognoses of this patient population.

Matching-adjusted indirect comparison of amivantamab vs mobocertinib in platinum-pretreated EGFR Exon 20 insertion-mutated non-small-cell lung cancer.

Aim: We assessed relative efficacy and safety of amivantamab versus mobocertinib in patients with non-small-cell lung cancer with EGFR exon 20 insertion (exon20ins) mutations who progressed on prior platinum-based chemotherapy. Materials & methods: This matching-adjusted indirect comparison used patient-level data from CHRYSALIS (NCT02609776) and aggregate data from a mobocertinib trial (NCT02716116) to match populations on all clinically relevant confounders. Results: While both agents had similar efficacy for time-to-event outcomes, objective response rate was significantly higher for amivantamab. 15 of 23 any-grade treatment-related adverse events reported for mobocertinib were significantly less common for amivantamab versus only two for mobocertinib. Conclusion: Results suggest that amivantamab has an improved response rate with similar survival and a more favorable safety profile versus mobocertinib in EGFR exon20ins non-small-cell lung cancer.

Amivantamab Compared with Real-World Physician's Choice after Platinum-Based Therapy from a Pan-European Chart Review of Patients with Lung Cancer and Activating EGFR Exon 20 Insertion Mutations.

Patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor gene (EGFR) Exon 20 insertions (Exon20ins) at the second line and beyond (2L+) have an unmet need for new treatment. Amivantamab, a bispecific EGFR- and MET-targeted antibody, demonstrated efficacy in this setting in the phase 1b, open-label CHRYSALIS trial (NCT02609776). The primary objective was to compare the efficacy of amivantamab to the choices made by real-world physicians (RWPC) using an external control cohort from the real-world evidence (RWE) chart review study, CATERPILLAR-RWE. Adjustment was conducted to address differences in prognostic variables between cohorts using inverse probability weighting (IPW) and covariate adjustments based on multivariable regression. In total, 114 patients from CHRYSALIS were compared for 55 lines of therapy from CATERPILLAR-RWE. Baseline characteristics were comparable between the amivantamab and IPW-weighted RWPC cohorts. For amivantamab versus RWPC using IPW adjustment, the response rate ratio for the overall response was 2.14 (p = 0.0181), and the progression-free survival (PFS), time-to-next-treatment (TTNT) and overall survival (OS) hazard ratios (HRs) were 0.42 (p < 0.0001), 0.47 (p = 0.0063) and 0.48 (p = 0.0207), respectively. These analyses provide evidence of clinical and statistical benefits across multiple outcomes and adjustment methods, of amivantamab in platinum pre-treated patients with advanced NSCLC harboring EGFR Exon20ins. These results confirm earlier comparisons versus pooled national registry data.

An Adjusted Treatment Comparison Comparing Amivantamab Versus Real-World Clinical Practice in Europe and the United States for Patients with Advanced Non-Small Cell Lung Cancer with Activating Epidermal Growth Factor Receptor Exon 20 Insertion Mutations.

INTRODUCTION: Patients with advanced, epidermal growth factor receptor (EGFR)-mutated, non-small cell lung cancer (NSCLC) with Exon 20 insertion mutations (Exon20ins) have poor prognoses, exacerbated by a previous lack of specific treatment guidelines and unmet need for targeted therapies. Amivantamab, an EGFR and MET bispecific antibody, demonstrated efficacy and tolerability in patients with advanced EGFR-mutated NSCLC with Exon20ins following platinum-based therapy in CHRYSALIS (NCT02609776; Cohort D+). Since CHRYSALIS was single-arm, individual patient data (IPD)-based adjusted analyses versus similar patients in real-world clinical practice (RWCP) were conducted to generate comparative evidence. METHODS: RWCP cohorts were derived from seven European and US real-world sources, comprising patients fulfilling CHRYSALIS Cohort D+ eligibility criteria. Amivantamab was compared with a basket of RWCP treatments. Differences in prognostic characteristics were adjusted for using inverse probability weighting (IPW; average treatment effect among the treated [ATT]). Balance between cohorts was assessed using standardized mean differences (SMDs). Overall response rate (ORR; investigator- [INV] and independent review committee-assessed [IRC]), overall survival (OS), progression-free survival (PFS; INV and IRC) and time-to-next treatment (TTNT) were compared. Binary and time-to-event endpoints were analyzed using weighted logistic regression and proportional hazards regression, respectively. RESULTS: Pre-adjustment, baseline characteristics were comparable between cohorts. IPW ATT-adjustment improved comparability, giving closely matched characteristics. ORR (INV) was 36.8% for amivantamab versus 17.0% for the adjusted EU + US cohort (response rate ratio [RR]: 2.16). Median OS, PFS (INV) and TTNT were 22.77 versus 12.52 months (hazard ratio [HR]: 0.47; p < 0.0001), 6.93 versus 4.17 months (HR: 0.55; p < 0.0001) and 12.42 versus 5.36 months (HR: 0.44; p < 0.0001) for amivantamab versus the adjusted EU + US cohort, respectively. Results were consistent versus EU- and US-only cohorts, and when using IRC assessment. CONCLUSION: Adjusted comparisons demonstrated significantly improved outcomes for amivantamab versus RWCP, highlighting the value of amivantamab in addressing unmet need in patients with advanced EGFR Exon20ins NSCLC following platinum-based therapy. TRIAL REGISTRATION: CHRYSALIS: NCT02609776.