Recent progress in dissecting molecular mechanisms essential for the survival and propagation of cancer cells triggered rapid development of targeted therapies. Although many of these therapies produce impressive initial responses in tumor suppression, the onset of resistance is practically unavoidable. One of the main approaches for preventing this refractory condition relies on the development of effective combination therapies. Unfortunately, selection of optimal targets for combinatorial treatments is often confounded by limitations in our understanding of tumor biology. Here, we describe an unbiased comprehensive strategy that combines ex-vivo shRNA-based genome wide screening, proteomic profiling using BioID and patient tumor sequencing data analyses to overcome current challenges in identifying the best fit co-targeting agents. Integrating these strategies, we selected EGFR and EPHA2 receptors as molecules of choice for co-targeting in cancer cells, and generated a bispecific fully humanized anti-EGFR/EPHA2 antibody with druggable bioanalytical properties that very effectively suppresses tumor growth compared to its prototype therapeutic anti-EGFR antibody, cetuximab. Despite the overactivation of EGFR signaling in multiple malignancies, the therapeutic applicability of cetuximab is limited due to frequent resistance and could benefit from being used in a combination with another targeted compound. Our analysis indicates that EGFR and EPHA2 expression positively correlate in various cancer types and thus, are available for co-targeting in most tumors. Therefore, our work not only presents an efficient unbiased strategy for selecting optimal targets for combination therapies, but also describes a novel bispecific antibody, which has a high potential for being developed into a new clinically-relevant biologics effective in a broad variety of malignancies.