CP-506 can selectively eliminate hypoxic tumor cells. In our hands, CP-506 has several advantages compared to the previous HAP’s (see for example the very step curve of Fig1B). Tumor hypoxia & sensitivity to CP-506 are strong determinants of the antitumor effects of CP-506 which has an effect in 13 out of 15 solid tumours (Fig 5C: the resistant ones are not hypoxic, the very sensitive ones have an Homologous Recombination Defect). A phase 1 trial will start next year (funding by grants, submission to EMA and IRB completed ). There is a new momentum for HAP’s, hypoxia being a major cause of immunoresistance!