Infinity and MedImmune Announce Promising Biological Activity of Anti-Hsp90 Compound in Phase I GIST Trial

09-Nov-2006

Infinity Pharmaceuticals, Inc. and MedImmune, Inc. announced preliminary results from an open-label Phase I clinical study of IPI-504 in patients with Gleevec®-resistant metastatic gastrointestinal stromal tumors (GIST). IPI-504, Infinity's lead oncology drug candidate, is a proprietary small molecule inhibitor of Heat Shock Protein 90 (Hsp90) that is being jointly developed by Infinity and MedImmune.

This open-label, dose-escalation Phase I trial of IPI-504 is being conducted at the Dana-Farber Cancer Institute in Boston, Mass., under the direction of George Demetri MD, director of the Ludwig Center at Dana-Farber/Harvard and director of Dana-Farber's Center for Sarcoma and Bone Oncology. To date, 20 GIST patients have received IPI-504 at dose levels ranging from 90 to 400 mg/m2. IPI-504 is administered to patients on days 1, 4, 8, and 11, followed by 10 days off treatment (referred to as a "drug holiday"), in a 21-day cycle. Patients included in the study were heavily pre-treated and nearly all had failed prior therapy with Sutent® as well as Gleevec, two approved therapies for the treatment of GIST.

IPI-504 has been well-tolerated to date at all dose levels tested, and a maximum tolerated dose has not yet been identified. Investigators have observed evidence of biological activity for IPI-504 using positron emission tomography imaging, or PET. In 7 of 17 evaluated patients (41%), PET scans revealed a decrease in tumor uptake of 18-fluorodeoxyglucose, an imaging agent used to measure metabolic activity, in response to IPI-504 administration. In some cases, a rebound in tumor activity was observed during the drug holiday, followed by a decrease in tumor activity upon re-administration of IPI-504 in the next cycle. This pattern of tumor response appears to demonstrate biological activity of IPI-504. In addition to the observed PET responses, 6 of 15 evaluated patients (40%) received five or more cycles of therapy with IPI-504.

https://www.bionity.com/en/news/59314/infinity-and-medimmune-announce-promising-biological-activity-of-anti-hsp90-compound-in-phase-i-gist-trial.html