FGFR2 and neoplasm: The combination of BBI-2779 plus infigratinib resulted in significant tumour growth inhibition compared to vehicle-treated animals (P < 0.0001), with tumour regressions observed over the duration of the study, which was directly correlated with the suppression of further (adaptive) FGFR2 oncogene copy number amplification on ecDNA, otherwise induced by single-agent infigratinib (Fig. 4e,f).