Pembro promises Merck-y results in sarcoma.

Bone and soft tissue sarcomas (STS) have seen few advancements in systemic therapy options over the last several decades. But where other people see dismaying outcomes, Merck sees pembrolizumab potential. Reporting of the phase 2 SARC028 trial of pembro for metastatic or unresectable bone or STS (of all histologies) was published this month in Lancet Oncology. The results, like the patients, are all over the place--maybe to obscure the dismal outcomes--so we recommend glancing at figures 2 and 4 for a quick and clear summary. Basically, half the patients had bone sarcomas and their diseases unfortunately blew through treatment. The other half of patients had STS, and most of these also blew through treatment with the exception of 4 of 10 undifferentiated pleomorphic sarcoma (UPS) patients exhibiting decreased tumor size. Merck’s conclusions: never give up. Further enrollment is being expanded among UPS patients to shore up positive results. We hope for the best but aren’t going to prepare ourselves for a phase 3 pembro showing in sarcoma anytime soon.