PARP1 and neoplasm: ARV-771 caused degradation of c-MYC with an IC50 < 1 nM and apoptosis of cells through PARP cleavage.152 A VCaP tumor model which represents the clinical setting of AR overexpression following androgen-deprivation therapy, was chosen for evaluation of the potency of ARV-771 in vivo in the VCaP tumor model was chosen to.