The open-label trial was conducted in Europe in collaboration with Aeterna Zentaris’ partner Spectrum Pharmaceuticals. Originally designed for 48 patients, the trial was extended to 64 patients where four groups of 16 patients received different intramuscular dosage regimens of the luteinizing hormone releasing hormone (LHRH) antagonist, ozarelix, to assess its safety and efficacy.
The study achieved its primary endpoint of defining a tolerable dosage regimen of ozarelix that would ensure continuous suppression of testosterone at castration level for a three-month test period.
An important secondary efficacy endpoint of the study aimed at assessing tumor response as determined by a 50% or greater reduction of serum PSA levels, compared to baseline, was also achieved.
“We are very excited with these results which confirm the mechanism of action of our LHRH antagonist approach and the potential effectiveness of ozarelix to achieve sustained suppression of sexual hormones at castration levels and, consequently, could allow for the treatment of hormone-dependent cancers,” commented Dr Jurgen Engel, executive vice president of global R&D and COO at Aeterna Zentaris.
The company has also initiated, again in collaboration with Spectrum Pharmaceuticals, an additional study which will enroll 32 patients at other European clinical sites to verify and optimize the findings derived from the cohort of patients having received 130mg of ozarelix per cycle.