Could combinations of new and old drugs enhance tumor cell death?

[...]several other chemotherapeutic agents are known to modulate autophagy and consequently blocking autophagic flux to increase cancer cell death (5-7). [...]of the mechanism for enhancing cancer cell death, either by blocking of the autophagic flux or other therapeutic pathways, high-throughput screening greatly facilitates the discovery of new uses for FDA approved ‘old drugs’ and selection of the next generation of anticancer chemotherapy. Besides repurposing studies, several new pharmacological classes aimed to interfere with obvious targets in the control of cell cycle, DNA repair and survival pathways are under development. In a study by McClendon etal., palbociclib hampered doxorubicin cytotoxicity in breast cancer cells, in a pathway dependent on diminished cleaved PARP and E2F1 levels, antagonize drugs that are dependent on cell cycle progression, such as anthracyclines avoiding progression of the cell cycle. [...]it emphasizes the growing notion that CDK4/6 inhibitors might antagonize drugs that are dependent on cell cycle progression, and the order in which the drugs are given might affect treatment efficiency and resistance (17 ,18). First clinical trial to take a CDK inhibitor to US FDA approval as first-line chemotherapy. 15.