Fig. 2.

Patients with prostate cancer treated with an anti-tumor vaccine and/or PD-1 blockade develop increased IDO activity. Kyn:trp ratios were evaluated in patients prior to treatment and after 12 weeks treatment with, pembrolizumab alone (n = 8, panel a), pTVG-HP DNA vaccine alone (n = 10, panel b), or both agents together (n = 6, panel c). Kyn:trp ratios were evaluated in subsets of patients who experienced any PSA decline over the same 12-week period of treatment (n = 8, panel d), and those who did not have any PSA decline over the same 12-week period of treatment (n = 16, panel e). Comparisons were made with a paired student t test. Kyn:trp ratios were evaluated with respect to serum IFNγ concentration (panel f). Test of correlation was made by Spearman test