Early findings from an ongoing trial of TPST-1120 in combination with nivolumab have shown that TPST-1120 is well-tolerated, both as a single agent and in combination with nivolumab, and the combination has shown promising objective responses among subjects with disease previously refractory to anti-PD1 therapy, including 2 of 2 responders with pretreated renal cell carcinoma, and a subject with heavily pretreated cholangiocarcinoma, a tumor that generally does not respond to anti-PD1 alone. Here, PDCD1 is linked to cholangiocarcinoma.