Abstract. Introduction: Fibrolamellar carcinoma (FLC) displays upregulation of several oncogenes, including HER2, and multiple immune-suppressive mechanisms. We investigated the efficacy and safety of the pan-HER tyrosine kinase inhibitor neratinib as monotherapy (SUMMIT phase 2 basket study) or with immune checkpoint and/or mTOR inhibitors (compassionate-use program) in patients with FLC. Methods: Patients received neratinib 240 mg/day orally in SUMMIT, or as doublet or triplet combinations with pembrolizumab 2 mg/kg intravenously every 3 weeks, nivolumab 240 mg intravenously every 2 weeks, everolimus 7.5 mg/day orally, or sunitinib 37.5 mg/day orally under compassionate use. The primary endpoint in SUMMIT was objective response rate; safety was a secondary endpoint. Results: Fifteen patients with FLC received neratinib monotherapy in SUMMIT. The objective response rate was 5% (95% CI 0–21.8) and the disease control rate was 13.3% (95% CI 1.7–40.5). Upon progression, five had added im