Nivolumab as maintenance therapy following platinum-based chemotherapy in EGFR-mutant lung cancer patients after tyrosine kinase inhibitor failure: A single-arm, open-label, phase 2 trial.

BACKGROUND: As the outcome of immunotherapy can be improved when concurrently or sequentially combined with cytotoxic chemotherapy or radiotherapy, we investigated the efficacy of immunotherapy maintenance following platinum-based chemotherapy in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) after EGFR-tyrosine kinase inhibitor (EGFR-TKI) failure. METHODS: In this prospective, open-label, single arm phase 2 trial, we enrolled patients aged 18 years or older with EGFR-mutant NSCLC, which progressed after first- or second-line EGFR-TKI. Patients received platinum-based chemotherapy followed by nivolumab maintenance therapy. They were intravenously administered 240 mg of nivolumab every 2 weeks for 3 months followed by 480 mg every 4 weeks until disease progression or unacceptable toxic effects occurred. The primary endpoint was progression-free survival (PFS). Secondary outcomes were overall survival (OS) and incidence of grade 3-4 treatment-related adverse events (AEs). RESULTS: We enrolled 26 patients between May 2020 and July 2021. The median PFS was 1.7 months (95% CI: 0.401-2.999 months). The median OS was 21.4 months (95% CI: 18.790-24.010 months) with 6- and 12-month OS rates of 96.2% and 76.9%, respectively. The objective response rate was 7.7% (2/26) and disease control rate, 11.5% (3/26). The tumor mutational burden by next-generation sequencing in blood was not related to the treatment outcomes. Grade 3-4 treatment-related AEs occurred in four (15.4%) patients; the most frequent AE was increased alanine aminotransferase (7.7%). CONCLUSION: Nivolumab maintenance following platinum-based chemotherapy did not show clinical benefits after EGFR-TKI failure in patients with EGFR-mutant NSCLC.