Halozyme’s pegylated enzyme found to be effective in preclinical studies

The study showed that treatment of hormone resistant human prostate cancer in tumor bearing mouse models with intravenous pegylated-rHuPH20 enzyme (PEGPH20) in combination with the chemotherapeutic drugs, docetaxel (Taxotere) or liposomal doxorubicin (Doxil) resulted in a substantial increase in anti-tumor activity. The docetaxel combination treatment demonstrated significantly enhanced survival compared to treatment with the chemotherapeutic agent alone.

The effects of PEGPH20 were selective to prostate tumors producing hyaluronan (HA), consistent with the selective reduction of tumor interstitial fluid pressure (IFP). Treatment with PEGPH20 was well tolerated in non tumor-bearing mice without significant increases in neutropenia (depletion of neutrophils, a type of white blood cell) compared to chemotherapy alone.

Halozyme said that it is continuing its pharmacology, manufacturing and toxicology studies as part of its PEGPH20 development program in oncology. The company plans to initiate studies in cancer patients with PEGPH20 during the first half of 2009.

Gregory Frost, Halozyme’s vice president and CSO, said: “These findings clearly demonstrate the activity of our long acting PEGPH20 enzyme candidate against HA-rich tumors in combination with chemotherapy. By targeting tumors that overproduce the HA matrix component, PEGPH20 may selectively attack tumor interstitial fluid pressure and combined with chemotherapy, reduce tumor burden for a significant number of patients.”