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.