AACR 2014: Development of a Spontaneous In Vivo Cachexia Model Using the Champions TumorGraft® Platform
Development of a spontaneous in vivo cachexia model using the Champions TumorGraft® platform
Nathan Anderson1, Tin Khor1, Andrew Feldhaus2, Andreya Gatling1, Katie Olson2, John Latham2, David Sidransky3, Elizabeth M. Bruckheimer1. 1Champions Oncology, Baltimore, MD; 2Alder Biopharmaceuticals, Bothell, WA; 3Johns Hopkins University School of Medicine, Baltimore, MD
Cachexia is present in the majority of patients with advanced cancer progression and is not reversible through nutritional supplementation, leading to loss of skeletal muscle and adipose tissue. There are a lack of quality pre-clinical models for cachexia research. Previously, Champions Oncology reported a mouse cachexia model derived from a primary human renal cell carcinoma tumor implanted in immunocompromised mice. This model, CTG-0804, was developed using the innovative Champions TumorGraft® platform, which preserves the biological properties of the original human tumor. The Champions TumorGraft® platform demonstrated dramatic weight loss in these mice as the tumor grew. Plasma from these mice also showed elevated levels of human IL-6. We have now further characterized this TumorGraft model by evaluating standard of care (SOC) agents for renal cell carcinoma and anti-IL-6 compounds to determine the mechanism of cachexia. The SOC evaluation revealed that sorafenib, sunitinib, temsirolimus and bevacizumab as single agents provided a survival advantage by inhibiting tumor growth and preventing weight loss in these mice. Blockade of human IL-6 with tocilizumab or ALD518 did not inhibit tumor growth and weight loss still occurred, demonstrating the possibility of other pathways involved in the cachexia mechanism. In addition, the SOC data for sunitinib showed significant tumor growth inhibition, but no regression at the study end point. This correlated with the clinical profile, where sunitinib could not prevent metastasis and the patient eventually progressed. The TumorGraft model was molecularly characterized and mutation analysis revealed a KIT V530I mutation. This mutation has been reported in extra-abdominal aggressive fibromatosis (desmoid tumor) and acute myeloid leukemia patients that have responded to c-kit targeting therapies, such as imatanib and dasatinib. Further characterization of this TumorGraft is ongoing to include additional bioinformatics using gene expression and mutation pathway analyses. In summary, we have continued development of this cachexia model using the Champions TumorGraft® platform, along with molecular evaluation, to produce a robust and well-characterized approach for cachexia investigation which can also be applied to other areas of drug development and cancer research.