NEW YORK – Pasadena, California-based Arrowhead Pharmaceuticals on Tuesday announced that it had dosed its first patient in a Phase Ib study of its investigational RNA interference agent, ARO-HIF2.
While the primary aim of the study is to evaluate the safety and maximum tolerated dose of the agent in patients with advanced clear cell renal cell carcinoma, investigators will also conduct extensive exploratory analyses to assess patients' HIF gene expression after treatment with ARO-HIF2, and the relationship between HIF gene expression and patients' response to treatment.
Specifically, in addition to post-dose tumoral expression of HIF gene expression, the study's exploratory endpoints include Karnofsky Performance Status, the correlation between patients' tumor shrinkage and their tumors' HIF2a gene expression and tumor integrin expression, and the correlation of their integrin expression with changes in HIF gene expression. Additionally, investigators will assess patients' serum biomarkers of ARO-HIF2 activity, the correlation between renal cell carcinoma-related gene expression to ARO-HIF2 activity, and patients' plasma and urine metabolites.
ARO-HIF2 is designed to inhibit the production of HIF-2α, which is associated with tumor metastasis and progression in patients with renal cell carcinoma. Over 90 percent of patients with clear cell renal cell carcinoma have tumors that express a mutant form of the tumor-suppressing Von Hippel-Landau protein, resulting in an inability to degrade HIF-2α.
"We believe that HIF-2α is an attractive target for RNAi-based gene silencing," Javier San Martin, Arrowhead's chief medical officer, said in a statement. "This is very exciting for us at Arrowhead and, we think, represents a significant step towards reaching the full therapeutic potential of RNA interference."