63MO Rechallenge of anlotinib in patients with advanced soft tissue sarcoma after progression on prior anlotinib treatment: A multicenter retrospective study

Background: NTRK gene fusions are oncogenic drivers in multiple tumour types.Larotrectinib (laro) is the first-in-class, highly selective TRK inhibitor approved for tumour-agnostic use in patients (pts) with TRK fusion cancer.Here, we report outcomes in paediatric pts with TRK fusion sarcomas who electively stopped laro while in response.Methods: Pts with TRK fusion cancer treated in the SCOUT trial (NCT02637687) were permitted to stop laro in the absence of on-treatment disease progression per investigator (INV) assessment (wait-and-see); pts who stopped laro were followed for progression.Pts who progressed were re-treated with laro and were reassessed by INV per RECIST v1.1.Most pts received laro 100 mg/m 2 (maximum dose: 100 mg) twice daily.Data cut-off date was 20 July 2023.