CTLA4 and telomere syndrome: The SARC028 trial was the first prospective multicenter, open-label, phase 2 study for immune checkpoint blockade in patients with advanced soft tissue and bone sarcomas, and pembrolizumab monotherapy has been reported to be associated with clinically meaningful and sustained objective responses in 18% of patients with STS.[9] The Alliance A091401 study evaluated the effectiveness of nivolumab (anti-PD-1) alone or in combination with ipilimumab (anti-CTLA-4) for the treatment of unresectable and metastatic sarcoma.