Io Therapeutics, Inc. Announces Initiation of Dosing in a Phase II Clinical Trial of IRX4204 in Patients with Advanced Prostate Cancer

Santa Ana, California – Thursday, October 6, 2011 – Io Therapeutics, Inc. announced today initiation of dosing in a phase II clinical trial with its experimental cancer therapeutic, IRX4204, in patients with advanced prostate cancer. The drug has previously completed a phase I/II clinical trial in patients with a variety of solid tumors, in which it was well tolerated for up to 20 months.

Targeted Mechanism of Action of IRX4204

“IRX4204 is a first in class, highly specific agonist of the rexinoid nuclear receptor pathways (RXR)”, said Rosh Chandraratna, Ph.D., President and Chief Scientific Officer of Io Therapeutics. He added, “Because IRX4204 has no retinoic acid receptor (RAR) agonism, we expect it to have improved safety and efficacy, compared to earlier generation, less specific rexinoid agonists which retained RAR agonist activity.” Pinchas Cohen, M.D., Professor at the UCLA School of Medicine and a member of the Io Therapeutics Scientific Advisory Board said, “Studies performed in my laboratory have previously demonstrated an important role of RXR in the induction of apoptosis, so called programmed cell death, in prostate cancer cells. This occurs through a specific complex-forming interaction of RXR protein with a second protein called Insulin-like Growth Factor Binding Protein-3 (IGFBP-3), a hormone whose circulating levels are known to be inversely related to the risk of developing prostate cancer. Population studies have shown that men with high blood levels of IGFBP-3 have decreased risk of developing prostate cancer.” Dr. Cohen further noted “Data from preclinical studies in my laboratory demonstrated synergy of the RXR agonist IRX4204, with IGFBP-3 in inducing the death of prostate cancer cells in vitro, as well as in inhibiting the growth of human prostate cancer tumors in vivo in a xeno-mouse model. These results support a specific targeted mechanism of action of IRX4204 of enhancing the cancer cell death promoting activity of the RXR and IGFBP-3 complex. This is a mechanism of action which may be of particular relevance to the treatment of prostate cancer.”

About Io Therapeutics

Io Therapeutics, Inc. is a privately held company headquartered in Santa Ana, California, focused on development of treatments for cancer and autoimmune diseases. Martin Sanders, M.D., Chairman and Chief Executive Officer of Io Therapeutics said, “The treatment of advanced prostate cancer remains a serious unmet medical need which IRX4204 may be able to address.” Sanders added, “Io Therapeutics has two additional unique clinical stage programs, an RARα-specific agonist for treatment of a spectrum of autoimmune diseases, and an RAR antagonist for prophylaxis and treatment of chemotherapy-induced neutropenia.”

Forward-looking statements

This news release contains “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995.

For more information on Io-Therapeutics and its product pipeline see: