Pyridoclax directly binds to Mcl-1. Pyridoclax induces apoptosis in combination with Bcl-xL-targeting siRNA or with ABT-737 in ovarian, lung, and mesothelioma cancer cells. Pyridoclax causes apoptosis in ovarian, and also in lung, and mesothelioma cancer cells when it is administrated in combination with Bcl-xL-targeting siRNA or Bcl-xL targeting molecules such as ABT-737 or its orally available derivative ABT-263. Pyridoclax sensitizes ovarian carcinoma cells to Bcl-xL-targeting strategies [1][2].