Here we evaluated the antitumor effect of a next-generation analog of ralaniten (EPI-7170) as a monotherapy or in combination with enzalutamide in prostate cancer cells that express AR-V7 that were resistant to enzalutamide... A combination of EPI-7170 and enzalutamide resulted in synergistic inhibition of proliferation of enzalutamide resistant cells that was consistent with results from cell cycle and clonogenic assays. In addition, this drug enhanced the anti-tumor effect of enzalutamide in enzalutamide-resistant CRPC preclinical models.