( Data From the Companies' Novel Heat Sh...)Infinity and MedImmune Present Updated Phase I Results of IPI-504,in GIST at ASCO Annual Meeting,Health

Data From the Companies' Novel Heat Shock Protein 90 Inhibitor Reveal Further Evidence of Safety, Tolerability, and Biological Activity

CAMBRIDGE, Mass. and GAITHERSBURG, Md., June 5, 2007 (PRIME NEWSWIRE) -- Infinity Pharmaceuticals, Inc. (Nasdaq:INFI) and MedImmune, Inc. (Nasdaq:MEDI) today announced updated interim results from a Phase I clinical trial of the companies' heat shock protein 90 (Hsp90) inhibitor, IPI-504, in patients with relapsed, refractory gastrointestinal stromal tumors (GIST) and other advanced soft tissue sarcomas. The data, presented at the 2007 Annual Meeting of the American Society for Clinical Oncology (ASCO), indicate that IPI-504 continues to be well tolerated and to show evidence of biological activity.

To date, 28 patients have received IPI-504 on two schedules of administration at dose levels ranging from 90 to 400 mg/m2. Assessment of biological activity in response to IPI-504 administration utilized positron emission tomography (PET) imaging to measure the decrease in tumor uptake of 18-fluorodeoxyglucose, an imaging agent used to measure metabolic activity. Scans were taken at baseline and during the first cycle of treatment after at least two doses. PET results for "Schedule A" (21-day cycle with patients treated on days 1, 4, 8, and 11, followed by 10 days off treatment) were assessed using the European Organization for Research and Treatment of Cancer's (EORTC) PET response criteria which entails a quantitative measurement using SUVmax (maximum standardized uptake value). PET results for "Schedule B" (uninterrupted twice-weekly dosing without a drug holiday) were assessed qualitatively. (See below for additional information about PET imaging and SUVmax.)

EORTC criteria for PET responses define Stable Disease as a change in SUVmax between 25 percent above and 25 percent below baseline, and a Partial Response as a decrease in SUVmax of 25 percent or more
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