AEterna Zentaris Announces Results of Japanese BPH Study

AEterna Zentaris, along with its Japanese partner Shionogi, has announced positive results from a Phase IIa trial with cetrorelix in benign prostatic hyperplasia (BPH) initiated in 2005 in Japan. Results showed that cetrorelix, the company's lead luteinizing hormone-releasing hormone (LHRH) antagonist, was safe and well tolerated at all dosage regimens.

Furthermore, Japanese patients responded to cetrorelix with a transient reduction of testosterone concentration in blood, which did not reach or remain at the castration level. Additionally, none of the dosage regimens tested caused a suppression of prostate-specific antigen levels. Finally, data generated with Japanese patients showed that the bioavailability of cetrorelix was similar to that observed in non-Japanese patients.

On the basis of this study, Shionogi initiated a 300-patient Phase IIb study to assess primarily the efficacy of cetrorelix in BPH in Japanese patients.

"Shionogi's decision to initiate a Phase IIb trial in BPH combined with our own ongoing Phase III program with cetrorelix in this same indication allows us to pursue the development of cetrorelix at an international level and represents an opportunity to potentially gain access to large markets worldwide," Gilles Gagnon, president and CEO of AEterna Zentaris, said.

In the a multicenter, placebo-controlled, randomized trial, the sustained-release formulation cetrorelix pamoate was administered intramuscularly at single or multiple dosing schedules. A total of 50 patients were included in five dosing groups corresponding to single administration of 30, 60 or 90 mg of cetrorelix and multiple administration of 60 and 90 mg three times eight weeks apart.

Cetrorelix is marketed under the brand name Cetrotide, the first LHRH antagonist approved for therapeutic use as part of in vitro fertilization programs in Europe, the U.S. and Japan.