SUMMARY: The FDA on March 1, 2024, approved Amivantamab-vmjw (RYBREVANT®) with Carboplatin and Pemetrexed for the first-line treatment of locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) exon 20 insertion mutations, as detected by an FDA-approved test. The FDA also granted traditional approval to Amivantamab-vmjw for adult patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations, as detected by an FDA-approved test, whose disease has progressed on or after platinum-based chemotherapy. FDA previously granted accelerated approval for this indication based on Phase 1 CHRYSALIS study.
The American Cancer Society estimates that for 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer.
Approximately 10-15% of Caucasian patients and 35-50% of Asian patients with Adenocarcinomas, harbor activating EGFR mutations, and 90% of these mutations are either exon 19 deletions or L858R substitution mutation in exon 21. EGFR exon 20 insertion mutations are the third most common after L858R and exon 19 deletions and occur in about 2-3% patients with NSCLC and are insensitive to EGFR Tyrosine Kinase Inhibitors (TKIs) due to an altered conformation of the kinase active site. Next-Generation sequencing provides an alternative to Polymerase Chain Reaction (PCR)-based tests, which fail to identify 50% or more of exon 20 insertion mutations. Patients with EGFR exon 20 insertion mutations have a 5-year Overall Survival (OS) of 8% in the frontline setting, compared to an OS of 19% for patients with EGFR exon 19 deletions or L858R mutations. There is therefore a clinically unmet need for this patient group, as there are no approved targeted therapies available, and platinum-doublet chemotherapy remains the standard of care for these patients.
Amivantamab (RYBREVANT®) is a fully human bispecific antibody directed against EGFR and MET receptors, with immune cell-directing activity. Amivantamab binds extracellularly and simultaneously blocks ligand-induced phosphorylation of EGFR and c-MET, inhibiting tumor growth and promoting tumor cell death. Further, Amivantamab downregulates receptor expression on tumor cells thus preventing drug resistance mediated by new emerging mutations of EGFR or c-MET. By binding to the extracellular domain of the receptor protein, Amivantamab can bypass primary and secondary TKI resistance at the active site. Additionally, Amivantamab has been shown to engage macrophages, monocytes, and Natural Killer cells through its Fc domain. Amivantamab in combination with Carboplatin and Pemetrexed demonstrated synergy, with improvement in Response Rates, in previously published studies.
PAPILLON trial is an international, randomized, Phase III study, conducted to assess the efficacy and safety of Amivantamab plus chemotherapy as compared with standard chemotherapy alone, as first-line treatment, in patients with advanced NSCLC with EGFR exon 20 insertions. In this study, 308 patients (N=308) were randomly assigned 1:1 to receive Amivantamab plus chemotherapy (N=153) or chemotherapy alone (N=155), given in 3 week cycles. Amivantamab was given at a dose of 1400 mg (1750 mg for a body weight of 80 kg or more) IV weekly for the first 4 weeks, with the first infusion split over 2 days (at a dose of 350 mg on cycle 1, day 1, and the remainder on cycle 1, day 2). Starting at cycle 3 (week 7), the dose of Amivantamab was increased to 1750 mg IV (2100 mg for a body weight of 80 kg or more) administered every 3 weeks until disease progression. Carboplatin was administered at AUC 5 IV every 3 weeks for up to 4 cycles. Pemetrexed was administered at a dose of 500 mg/m2 IV every 3 weeks until disease progression. Both treatment groups were well balanced and the patients mutational status was determined by local testing of tissue samples in 92% of cases, and plasma samples in 8% of cases. Patients with treated brain metastases were eligible if they were asymptomatic. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive Amivantamab monotherapy. The Primary end point was Progression Free Survival (PFS) as determined by Blinded Independent Central Review. Secondary end points included Objective Response Rate (ORR), Overall Survival (OS), Duration of Response and Safety.
At a median follow-up of 14.9 months, the median PFS was significantly longer in the Amivantamab plus Chemotherapy group and was 11.4 months, compared to 6.7 months in the chemotherapy alone group (HR=0.40; P<0.001). At 18 months, the PFS in the Amivantamab plus chemotherapy group was 31% and 3% in the chemotherapy group. The Objective Response was 73% in the Amivantamab plus chemotherapy group and 47% in the chemotherapy alone group (P<0.001). Overall Survival results were immature at the time of current analysis, with a trend toward improvement in Overall Survival despite a high rate of crossover for the control arm (42%).
The most common adverse events associated with Amivantamab plus chemotherapy were reversible hematologic and EGFR-related toxic effects and included rash, nail toxicity, stomatitis, infusion-related reaction, fatigue, diarrhea, nausea and vomiting. Approximately 7% of patients discontinued Amivantamab due to adverse reactions.
It was concluded that Amivantamab in combination with chemotherapy resulted in superior efficacy as compared with chemotherapy alone, in previously untreated advanced NSCLC patients with EGFR exon 20 insertions.
Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions. Zhou C, Tang K-J, Cho BC, et al. for the PAPILLON Investigators. N Engl J Med 2023;389:2039-2051.