PR-104 is a highly specific hypoxia-activated agent that cross-links DNA, enabling its application in various tumor xenograft models. Functioning as a pre-prodrug of nitrogen mustard, PR-104 undergoes efficient conversion to the dinitrobenzamide mustards alcohol form, known as PR-104A[1].

PR-104 demonstrates differential effects under various conditions in SiHa cells, showing enhanced inhibition of radiation-induced DNA single-strand breaks in hypoxic conditions compared to aerobic conditions at a concentration of 80 μM for 1 hour. At a higher concentration of 100 μM for the same duration, it triggers the phosphorylation of Ser139 on histone H2AX. Furthermore, with a dosage of 0.266 mmol/kg over 18 hours, PR-104 exhibits efficacy against hypoxic cells post-irradiation. Its effectiveness varies across cell lines, exhibiting a range in IC50 values from as low as 0.51 μmol/L in H460 cells to as high as 7.3 μmol/L in PC3 prostate cells.

PR-104 (0.56 mmol/kg; i.v. or i.p.; 0-2 hours) increases the plasma area under the curve, while PR-104 (0.23 mmol/kg; i.p.; 100 days) demonstrates antitumor activity[1].