Real-world therapeutic strategies and survival outcomes in advanced HER2 -mutant non-small cell lung cancer.

Abstract

Background: Limited information is available regarding the clinical features and outcomes of advanced human epidermal growth factor receptor 2 ( HER2 )-mutant non-small cell lung cancer (NSCLC) in Taiwan, despite expanding treatment options for this distinct subtype. This study aimed to investigate the clinical characteristics and outcomes of HER2-mutant NSCLC in a real-world setting.

Methods: Relevant data were collected from patients with advanced or recurrent HER2 -mutant NSCLC who received systemic therapy between 2011 and 2021 and were followed up until 2022 at two medical centers in Taiwan. Clinical features, treatment responses, and survival-related factors were analyzed.

Results: This study included 45 patients (median age: 59.7 [range: 41.3-78.7] years). A775_G776insYVMA was the most common HER2 mutation subtype (57.8%), followed by G778_P780dup (11.1%). Approximately 53.3% of the patients received first-line platinum-based chemotherapy (PC) alone, whereas 13.3% received PC combined with an immune checkpoint inhibitor (ICI). The median overall survival (OS) and progression-free survival (PFS) after first-line therapy were 25.8 and 4.4 months, respectively. The objective response rate was generally higher in patients receiving first-line PC + ICI than those receiving PC alone (33.3% vs 12.5%; p = 0.269). Furthermore, patients receiving PC + ICI had longer PFS than those receiving PC alone (9.5 vs 4.4 months; p = 0.131) and those receiving tyrosine kinase inhibitor/ICI monotherapy (9.5 vs 0.5 months; p = 0.015). Compared with patients having other NSCLC subtypes, those carrying HER2 exon 20 insertion mutations had shorter median PFS (17.3 vs 2.9 months; p = 0.043) and OS (not reached vs 19 months; p = 0.031).

Conclusion: This study highlights the clinical features and outcomes of advanced HER2 -mutant NSCLC in Taiwan. PC + ICI may be more effective than other regimens as first-line therapy. The prognostic impact of HER2 exon 20 insertion mutations warrants further investigation.