PD-1 blockade using pembrolizumab in adolescent and young adult patients with advanced bone and soft tissue sarcoma.

3060Background: Sarcomas represent 10–15% of cancers in adolescent and young adult (AYA) patients, and survival for those with metastatic disease or after relapse is poor. Immunotherapy with checkpoint inhibition has improved outcomes in multiple tumour types, but there are limited data on the efficacy of immunotherapy in advanced sarcomas, particularly within the AYA population. Methods: We retrospectively reviewed AYA patients with advanced bone and soft tissue sarcoma who received self-funded pembrolizumab at Chris O’Brien Lifehouse and Children’s Hospital Westmead. Initial response was evaluated after cycle three or four using RECIST v1.1 criteria. Results: Fourteen AYA patients with sarcoma received pembrolizumab 2mg/kg IV every 3 weeks from May 2015 to December 2016. Median age was 24 (14 – 35), male to female was 7:7, ECOG PS was 0 – 1 in 6 patients, 2 in 6 patients and 3 – 4 in 2 patients. Malignancy type included three patients with osteosarcoma (OS), five patients with Ewing sarcoma (ES), two pa...