A favorable antitumor efficacy of sotorasib in a patient with KRAS G12C-mutated pulmonary large-cell neuroendocrine carcinoma.

The recent studies with comprehensive genomic analyses demonstrated that a certain proportion of patients with pulmonary large-cell neuroendocrine carcinoma (LCNEC) harbors some driver gene alterations. We herein present a case of 79-year-old man with Kirsten rat sarcoma virus oncogene homologue G12C-mutated pulmonary LCNEC who were treated with chemo-immunotherapy in the first-line setting. Sotorasib which was administered as second-line therapy showed a favorable therapeutic efficacy of partial response. Although sotorasib induced severe hepatobiliary disorder which forced us to terminate the treatment, the antitumor response was sustained for up to 5.6 months which was almost comparable to the therapeutic efficacy reported in pivotal clinical trials. Our case and related literature review suggest that the multiplex genetic mutation-detection assay should be considered for patients with LCNEC. Furthermore, it also suggests that biomarkers which enable us to distinguish patients who are likely to harbor driver gene alterations are required in near future.