Cancer cell lines and patient derived xenografts (PDX) are commonly engrafted and screened in mouse models of cancer. However, the OncoRat outperforms the mouse as a xenograft model as it is more reliable, efficient & robust. OncoRat consistently demonstrates higher efficiency and more desirable uniformity than mouse tumor model growth profiles. OncoRat is also ideal for downstream analysis as it produces samples ten times larger than mice and is metabolically closer to humans making it the preferred model for efficacy, pharmacokinetics (PK), and toxicology. Hera provides screening services using the OncoRat as well as PDX model services.
Serial blood draws & tumor biopsies in OncoRat
Tumor xenografts are limited to a maximum of 10% of the total animal body weight. In mice with body weights topping out at 20-30 grams, the tumors can only grow to 2-3 grams or 2,000-3,000 mm3, limiting the data that investigators can obtain per mouse for molecular analysis, drug exposure and PK/PD, as well as immune cell infiltration. The OncoRat reaches weights of 200-300 grams, permitting tumors in the range of 20,000-30,000 mm3 as well as enough blood for serial draws for biomarker analysis.
This larger size enables serial blood draws, biopsies and Fine Needle Aspirates (FNA) to study tumor and biomarker responses over time in the same animal without significantly effecting tumor kinetics.
In this control study OncoRats bearing MDVR drug resistant VCaP prostate tumors underwent one FNA core sampling weekly for four weeks and four core samplings in week five. The tumor samplings can be prepared and used for molecular analysis, tumor PK/PD, and immune cell infiltration without taking rats out of the study.
Ponnusamy S, He Y, Hwang DJ, Thiyagarajan T, Houtman R, Bocharova V, Sumpter BG, Fernandez E, Johnson D, Du Z, Pfeffer LM, Getzenberg RH, McEwan IJ, Miller DD, Narayanan R. Orally Bioavailable Androgen Receptor Degrader, Potential Next-Generation Therapeutic for Enzalutamide-Resistant Prostate Cancer. Clin Cancer Res. 2019 Sep 3 (on-line).