To achieve tumor-specific distribution and accumulation of the ICD inducer and IDO-1 inhibitor, enzyme-activatable prodrug vesicles (termed EAPVs), with the enzyme matrix metalloproteinase-2/9 (MMP-2/9), were codelivered with a PEGylated PS (e.g., PPa) and NLG919 (Fig. 3a, b) [86]. Here, IDO1 is linked to neoplasm.