11550 Background: Preliminary studies have suggested that the detection, quantification, and profiling of ctDNA in patients with sarcoma is feasible and may improve prognostication, measure treatment response, and detect relapse. However, data related to impact of ctDNA profiling to tailor therapy in patients with advanced disease are lacking. Methods: Patients with advanced soft-tissue sarcomas (STS) have been included in two ongoing institutional molecular profiling studies (BIP: NCT02534649, STING: NCT04932525). Genomic analysis (ctDNA in all cases and tissue when available) was performed by using the Foundation One Liquid CDx Assay (324 genes, tumor mutational burden [TMB], microsatellite instability status). Each individual genomic report was reviewed and discussed weekly by a multidisciplinary tumour board dedicated to precision medicine, attended by experts in clinical oncology, molecular biology, and clinical genetics. Actionable targets were defined by the MTB according to the existing level of evidence (ESCAT), and molecular-based treatment suggestions were proposed where possible. Results: Between December 2020 and August 2021, 98 patients with metastatic STS underwent ctDNA profiling. Median time to assay results was 12 days. Results were contributive for 86 patients (88%). At least one actionable target (range 1-4) was detected in 35 patients (36%) including high tumor mutational burden (> 16 mutations/Mb) for 1 patient (1%) and alteration of the DNA repair response pathway for 12 patients (12%). Overall, the MTB recommended a matched therapy for 27 patients (28%). 40 patients underwent also NGS of tissue besides ctDNA profiling. The number of actionable alterations was similar in 26 (65%), whereas it was higher in tissue for 10 (25%) and in liquid for 4 (10%) patients. Conclusions: This large-scale study demonstrates that liquid biopsy with a large NGS ctDNA panel is an efficient approach to match patients to genomically directed clinical trials/targeted therapies in patients with advanced STS. Outcomes of patients treated with matched therapy will be presented at the meeting.