Selective TRK inhibition by larotrectinib offers a novel, highly specific and highly effective therapeutic option for IFS carrying the characteristic ETV6-NTRK3 gene fusion.
We report a case of refractory IFS with constitutive activation of the tropomyosin-related kinase (TRK) signaling pathway from an ETS variant gene 6-neurotrophin 3 receptor gene (ETV6-NTRK3) gene fusion.
We investigated the presence or absence of ETV6 rearrangements and numerical abnormalities of chromosome 11 by using fluorescence in situ hybridization on paraffin-embedded material from five cases of IFS, two of CMN, and one of mixed type (CMN and IFS) found in our files.