Updated trial results show a sustained clinical benefit with amivantamab in patients with non-small cell lung cancer (NSCLC) and EGFR exon 20 insertions whose disease progressed on platinum-based chemotherapy.
These results, from the phase 1 CHRYSALIS trial, were presented at the European Lung Cancer Congress 2023.
The CHRYSALIS trial (ClinicalTrials.gov Identifier: NCT02609776) included 114 heavily pretreated patients with NSCLC and EGFR exon 20 insertions. The patients’ median age was 62 (range, 36-84) years, 61% were women, and 25% had brain metastases.
The median number of prior treatments was 2 (range, 1-7). All patients had received platinum chemotherapy, 44% had received immunotherapy, and 20% had received EGFR tyrosine kinase inhibitors.
On study, patients received amivantamab monotherapy. At the data cutoff, the median follow-up was 19.2 months, the median treatment duration was 7.5 months, and 48 patients (42%) were still alive.
The median progression-free survival (PFS) was 6.9 months. The 1-year PFS rate was 35.4%, and the 2-year PFS rate was 13.7%.
The median overall survival (OS) was 23 months. The 1-year OS rate was 73.3%, and the 2-year OS rate was 47.2%.
Amivantamab demonstrated consistent efficacy regardless of prior therapy, said study presenter Pilar Garrido, MD, PhD, of Hospital Universitario Ramon y Cajal in Madrid.
Dr Garrido noted that 48 patients (42%) had a sustained clinical benefit, which was defined as being on amivantamab for 12 or more cycles. Clinical benefit was more likely among patients who achieved a partial response or better, patients with good performance status, and those who did not have baseline alterations in the RAS/RAF/MEK pathway.
At the data cutoff, treatment was ongoing in 15 patients (13%) who had received amivantamab for a median of 2.6 years. Seven of these patients were still progression-free, and 8 were receiving treatment beyond disease progression.
Dr Garrido noted that no new safety signals were detected with longer follow-up. Treatment-related dose interruptions occurred in 29% of patients, dose reductions occurred in 18%, and discontinuations occurred in 7%.
The most frequent adverse events of any grade were rash (89%) and infusion-related reactions (67%). The most common grade 3 or higher adverse events were venous thromboembolism (6%) and dyspnea (5%).
Amivantamab is currently under investigation in the frontline setting in the phase 3 PAPILLON study (ClinicalTrials.gov Identifier: NCT04538664). Researchers are comparing amivantamab plus chemotherapy with chemotherapy alone in patients with NSCLC and EGFR exon 20 insertions.
Disclosures: This research was supported by Janssen Research & Development, LLC. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Garrido Lopez P, Girard N, Cho BC, et al. Long-term efficacy, safety and predictors of response to amivantamab among patients with post-platinum EGFR Ex20ins-mutated advanced NSCLC. ELCC 2023. March 29 – April 1, 2023. Abstract 3O.