Ferring has started a pivotal trial of degarelix, its candidate drug for prostate cancer, after encouraging results in Phase II testing.

Degarelix was found to provide rapid reductions in testosterone and prostate-specific antigen (PSA), a biomarker for prostate cancer, in the Phase IIb study, which was presented at the European Association of Urology meeting in Paris.

Degarelix acts by blocking gonadotrophin-releasing hormone and is given just once a month by subcutaneous injection. Ferring claims the drug prevents the initial mobilisation in testosterone that occurs with current GnRH agonists, which can cause a worsening of prostate cancer symptoms.

A GnRH antagonists already on the market for prostate cancer is Praecis Pharmaceuticals’ Plenaxis (abarelix), which was cleared for marketing in the USA in 2003 but failed to make make much headway in the marketplace, with the company electing to stop promoting it last year.

Meanwhile, Aeterna Zentaris has ozarelix in Phase II trials for prostate cancer, in partnership with Spectrum Pharmaceuticals.