Infinity Pharmaceuticals, Inc. (NASDAQ: INFI) today announced updated data from the Phase 1b portion of an ongoing Phase 1b/2 clinical trial of saridegib (also known as IPI-926) in combination with the chemotherapy gemcitabine in patients with previously untreated, metastatic pancreatic cancer. These findings were presented during a poster session at the American Society of Clinical Oncology's 2012 Gastrointestinal Cancers Symposium (ASCO-GI) in San Francisco (Abstract #213) and support the ongoing Phase 2, double-blind, randomized, placebo-controlled trial comparing saridegib in combination with gemcitabine to placebo and gemcitabine. In October 2011, Infinity announced the completion of enrollment in the Phase 2 portion of the trial, and the company expects to report topline Phase 2 data in the second half of 2012. The primary endpoint of the Phase 2 portion of the trial is overall survival.
Data from the Phase 1b, open-label study in 16 patients showed that saridegib in combination with gemcitabine was well-tolerated and clinically active. As previously reported, the recommended Phase 2 dose of saridegib in combination with gemcitabine was established at 160 mg administered orally once daily, which is the maximum tolerated dose of saridegib when administered as a single agent. The adverse events observed were consistent with the known safety profile of each agent. In addition, partial responses were observed in five of 16, or 31 percent, of patients treated at three different dose levels of saridegib. New data reported today showed that median progression-free survival was 7.6 months (95 percent confidence interval (CI): 3.5 - 8.7 months) and median overall survival was 10.2 months (95 percent CI: 5.7 - 12.3 months).
"Pancreatic cancer has the lowest survival rate among all the major cancers, and new treatments that can improve survival rates are desperately needed," stated Charles Fuchs, M.D., MPH, director, Gastrointestinal Cancer Center at Dana-Farber Cancer Institute and professor of medicine at Harvard Medical School. "I look forward to seeing the results from the ongoing Phase 2 trial."
Saridegib is a novel, oral, small molecule that inhibits Smoothened, a key component of the Hedgehog pathway. In preclinical models of pancreatic cancer, the Hedgehog pathway signals from the tumor to the surrounding environment to create a thick, fibrous tissue that provides support for tumor growth and prevents chemotherapy from reaching the tumor effectively. Inhibiting Smoothened with saridegib may represent a fundamentally new approach to treating pancreatic cancer by depleting the fibrous tissue and improving blood flow, thereby facilitating the delivery of chemotherapy to the tumor.
"Acknowledging the limitations of assessing progression-free and overall survival in a small, single-arm Phase 1b trial, we are encouraged by these data and hope to confirm these results in our ongoing Phase 2, double-blind, randomized, placebo-controlled trial," stated Pedro Santabárbara, M.D., Ph.D., chief medical officer at Infinity. "We are also continuing to develop saridegib in additional indications, including myelofibrosis and chondrosarcoma, in which Hedgehog pathway inhibition could offer a new approach to treating cancers for which current therapeutic options are limited."
Source: Infinity Pharmaceuticals, Inc.