In parallel with the development of IPI-504 (retaspimycin hydrochloride), Infinity is developing IPI-493, its proprietary oral Hsp90 chaperone inhibitor. Hsp90 is an emerging major therapeutic target of interest for the treatment of a broad range of cancers.

Infinity is currently evaluating IPI-493 in two Phase 1 clinical trials - one in patients with advanced solid tumors and one in patients with advanced hematological malignancies. These studies are designed to evaluate the safety, tolerability and pharmacokinetics of IPI-493, and to determine a recommended dose and schedule for subsequent studies. Preliminary data for these Phase 1 studies are expected to be reported in 2011.

Infinity has presented preclinical data demonstrating anti-tumor activity of IPI-493 and evidence of dose-dependent inhibition of tumor growth in preclinical models of non-small cell lung cancer (NSCLC), with regression seen at higher doses. These data were presented at the 2008 EORTC-NCI-AACR Symposium on “Molecular Targets and Cancer Therapeutics.” IPI-493 has also demonstrated strong pharmaceutical properties in vitro and in vivo, including potent inhibition of Hsp90, selectivity for cancer cells over normal cells and high oral bioavailability.