Drug sensitivity data acquired from solid tumor-derived cultures are often unsuitable for personalized treatment guidance due to the lengthy turnaround time. Here, we present a protocol for determining ex vivo drug sensitivities using fresh uncultured human lung tumor-derived EpCAM+ epithelial cells (FUTCs). We describe steps for drug testing in FUTCs to identify tumor cell-selective single or combination therapy in 72 h of sample processing. The FUTC-based approach can also be used to predict in vivo resistance to known targeted therapies. For complete details on the use and execution of this protocol, please refer to Talwelkar et al. (2021).