Infinity, MedImmune Begin Trial of IPI-504

Infinity Pharmaceuticals and MedImmune have started a Phase II trial of IPI-504, their lead heat shock protein 90 inhibitor, in patients with advanced hormone-refractory prostate cancer (HRPC).

The open-label, multicenter study will determine the antitumor activity of IPI-504 in patients with HRPC. Two groups of patients will be enrolled — one having no prior treatment with cytotoxic chemotherapy and one having had prior treatment with a Taxotere-(docetaxel) based chemotherapy.

The drug will be administered by IV at a 400-mg/m2 dose level on a three-week cycle of therapy. The trial will enroll 30 patients and will add an additional 10 patients in each arm if a response is observed in at least one patient in that arm.

The candidate also is being evaluated in the expansion phase of a Phase I trial in patients with metastatic gastrointestinal stromal tumors and soft tissue sarcomas and in the Phase II portion of a Phase I/II trial in patients with advanced nonsmall cell lung cancer, MedImmune said.