...we elected to evaluate merestinib and crizotinib in a HNSCC PDX model also bearing ETV6-NTRK3 gene fusion (Figure (Figure4,4, Supplementary Figure 5). Merestinib dosed daily at 24 mg/kg showed reduction of tumor growth relative to vehicle control (T/C=6.2%, p < 0.001) while crizotinib dosed 25 mg/kg twice daily did not show significant tumor growth reduction (T/C=76.9%, p=0.525) relative to vehicle. Together, merestinib displays potent anti-tumor effect in tumors with NTRK fusions.