Hera BioLabs is a contract research organization (CRO) utilizing gene editing technologies to create enabling preclinical research models for oncology & immuno-oncology. Hera’s platform model, the OncoRat SRG, is a SCID rat on the Sprague-Dawley background harboring a double knockout for the Rag2 and Il2rgamma genes. This enhanced immunodeficient rat model has a severely impaired immune system lacking B-cells, T-cells, and NK-cells. Hera’s mission with the OncoRat is to provide the best in vivo data with the fewest number of animals. Improved engraftment rates and growth profile reduce the number of animals that need to be inoculated for a xenograft efficacy study (see PDX and VCaP example). Pharmacokinetics and toxicology can be combined with efficacy in the rat. Serial blood sampling for PK and biomarkers (see VCaP tumor PSA biomarker) as well as serial tumor biopsies can be taken from the larger tumors. All these translational enhancements are realized without the need to remove animals from the study. While the long timeline required for the establishment of patient derived xenografts or PDX models in mice is often impractical; the OncoRat grows ~10x larger tumors enabling PDX establishment and efficacy studies in fewer passages and a shorter amount of time.