Infinity announces Phase 2 clinical trial results of IPI-504 for NSCLC

Infinity Pharmaceuticals, Inc. (Nasdaq:INFI) today reported the results from its Phase 2 clinical trial of IPI-504, the company's i.v.-administered Hsp90 chaperone inhibitor, in patients with advanced non-small cell lung cancer (NSCLC). Data reported show that IPI-504 demonstrated clinical activity in patients with NSCLC, in particular among patients with oncogenic anaplastic lymphoma kinase (ALK) gene rearrangements. Dr. Lecia Sequist of Massachusetts General Hospital will present the data in a poster discussion session on Monday, June 7 at the 2010 Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Ill. (Abstract #7517).

Infinity conducted a Phase 2 study of IPI-504 in patients with stage IIIb/IV NSCLC whose tumors had progressed after treatment with an EGFR tyrosine kinase inhibitor. The study was designed to evaluate the safety, tolerability, and anti-tumor activity of IPI-504. A total of 76 patients were enrolled and stratified by their EGFR mutation status. A subset of patients also underwent EGFR, KRAS and BRAF genotyping analysis, as well as a fluorescent in situ hybridization (FISH) assay to detect ALK gene rearrangements.

The results of the Phase 2 study show an objective response rate of seven percent in the overall study population: ten percent in patients who were EGFR wild-type, four percent in those with EGFR mutations, and twelve percent among KRAS wild-type patients. Among the patients with ALK rearrangements, there was a 67 percent response rate, with two of three patients experiencing partial responses and the third patient experiencing a 24 percent disease reduction, all three of whom received IPI-504 for at least six months. IPI-504 was generally well-tolerated in this study.

Infinity also reported supporting in vitro data demonstrating that the ALK rearrangement protein is a sensitive client of Hsp90 and that IPI-504 induces degradation of ALK thereby inhibiting downstream signaling pathways.

Together, these clinical and preclinical data support additional evaluation of the anti-tumor activity of IPI-504 in patients with NSCLC and ALK rearrangements. Validation of the clinical findings reported today is ongoing in an investigator-sponsored trial at Massachusetts General Hospital by Dr. Sequist.

"These are the first clinical data to suggest that patients with NSCLC and ALK rearrangements may preferentially respond to Hsp90 chaperone inhibition," stated Julian Adams, Ph.D., president of research and development, Infinity. "We are pleased to support Dr. Sequist's study in order to assess the clinical effects of Hsp90 chaperone inhibition in this discrete patient population. We look forward to learning more as the study progresses, and the data analysis may help inform potential paths forward for our Hsp90 chaperone inhibitors in this targeted lung cancer population."

IPI-504 is also being evaluated in a Phase 2 clinical trial in combination with Herceptin^® (trastuzumab) in patients with HER2-positive metastatic breast cancer. Infinity expects to evaluate interim data from this study in the near term, which will help determine how IPI-504 fits into its Hsp90 development strategy, and overall product portfolio, going forward. Infinity anticipates reporting preliminary data from the metastatic breast cancer study by the end of the year.

Infinity is also evaluating its orally administered Hsp90 chaperone inhibitor, IPI-493, in a Phase 1 clinical trial in patients with advanced solid tumors. In addition, active enrollment in a Phase 1 study in patients with advanced hematologic malignancies is anticipated in the near term. Infinity expects to report data from its Phase 1 program with IPI-493 in 2011.