Dr. Burgess on Pembrolizumab in Sarcoma

In the phase II SARC028 trial, single-agent pembrolizumab (Keytruda) demonstrated antitumor activity in patients with advanced soft tissue and bone sarcomas.

The primary endpoint of the SARC028 study was to look at the objective response rate based on RECIST 1.1 criteria. Although the response rate was approximately 20% in the overall population, a response of 44% was shown in a subgroup of patients with undifferentiated pleomorphic sarcoma.

In the undifferentiated pleomorphic sarcoma cohort, 4 out of 9 were had partial responses. Two out of 9 evaluable patients in the dedifferentiated liposarcoma cohort had partial responses. There were no responses in the leiomyosarcoma cohort and there was a short-lived response in the synovial sarcoma cohort.

In the bone arm, there were 2 partial responses. One was in the osteosarcoma cohort, and the other was in the chondrosarcoma cohort.