Infinity Pharmaceuticals, Inc. (NASDAQ: INFI) today announced topline data from its Phase 2 study of retaspimycin hydrochloride (HCl), a potent and selective heat shock protein 90 (Hsp90) inhibitor, in patients with non-small cell lung cancer (NSCLC) who had a history of smoking. In this double-blind, randomized, placebo-controlled study, retaspimycin HCl did not meet its pre-specified efficacy endpoints for demonstrating an improvement in overall survival in the total patient population or in patients with squamous cell carcinoma. In the study, the safety profile of retaspimycin HCl plus docetaxel was comparable to docetaxel and placebo. Infinity expects to present the final data in a peer-reviewed setting after all analyses are complete. The company will not initiate any new trials with retaspimycin HCl.
“Although our Phase 1b data in patients with non-small cell lung cancer were encouraging and there was a strong biological rationale for the combination treatment, further development of retaspimycin HCl plus docetaxel in this very challenging disease is not merited based on data from this rigorously conducted study. We appreciate the support of the patients and caregivers who participated in this trial,” stated Julian Adams, Ph.D., president of research and development at Infinity. “We will now focus our clinical research and development effort on IPI-145, our lead PI3K-delta,gamma inhibitor, for which we have encouraging data in patients with life-threatening hematologic malignancies.”
Based on encouraging preliminary activity observed in a Phase 1 study of IPI-145, Infinity’s potent, oral inhibitor of phosphoinositide-3-kinase (PI3K)-delta and PI3K-gamma, in patients with advanced hematologic malignancies (blood cancers), the company is conducting a Phase 2 trial of IPI-145 in patients with indolent non-Hodgkin lymphoma and planning a Phase 3 trial in patients with chronic lymphocytic leukemia. IPI-145 also has therapeutic potential in inflammatory diseases, and the company is conducting a Phase 2 trial of IPI-145 in patients with rheumatoid arthritis as well as an exploratory, signal-finding Phase 2a study of IPI-145 in mild, allergic asthma. Additionally, Infinity is conducting preclinical studies of IPI-443, its second oral PI3K-delta and PI3K-gamma inhibitor, which also has the potential to treat hematologic malignancies and inflammatory diseases.