A phase 1/2 study with talabostat mesylate (BXCL701) (Figure 1) in combination with the anti-programmed cell death 1 (PD-1) monoclonal antibody pembrolizumab recruits prostate cancer patients to assess safety and efficacy of the combined treatment (NCT03910660) (Table 1). This evidence concerns the gene PDCD1 and prostate carcinoma.