Arrowhead Pharmaceuticals Inc. announced positive interim results from AROHIF21001, a Phase 1b dose-finding clinical study of ARO-HIF2, the company's investigational RNA interference (RNAi) therapeutic being developed as a treatment for patients with clear cell renal cell carcinoma (ccRCC). The data presented provide initial proof of target engagement based on reductions in hypoxia inducible factor-2 alpha (HIF2a) expression, as well as an acceptable safety profile in response to escalating doses of ARO-HIF2. The data are being presented by James Brugarolas, M.D., Ph.D, Professor at University of Texas Southwestern Medical Center and investigator in the study, in a poster presentation at the 2022 American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU), being held February 17-19, 2022, in San Francisco, CA and online.

AROHIF21001 (NCT04169711) is a Phase 1b dose-finding clinical study in patients with advanced ccRCC to evaluate the safety of ARO-HIF2 and to determine the recommended Phase 2 dose. Secondary objectives include the assessment of pharmacokinetics and preliminary efficacy, based on Response Evaluation Criteria in Solid Tumors (RECIST). Exploratory objectives for AROHIF21001 are post-dose tumoral expression of HIF genes in response to treatment with ARO-HIF2, change in Karnofsky Performance Status (KPS), correlation of tumor response based on RECIST with tumor HIF2a gene expression and tumor integrin expression, correlation of integrin expression with changes in HIF gene expression, evaluation of serum biomarkers of ARO-HIF2 activity, correlation of RCC-related gene expression to ARO-HIF2 activity, and evaluation of plasma and urine metabolites.