Antisoma has unveiled impressive survival data from a Phase II study of its potential blockbuster ASA404, this time in hormone-refractory prostate cancer.

The data comes from a study in which patients were randomised to receive either 1200 mg/m2 ASA404 plus docetaxel or a control treatment of the latter chemotherapy alone. Antisoma noted that
the hazard ratio expressing the relative risk of death favoured the ASA404 group, while median survival in the two groups was similar at 17.0 and 17.2 months, respectively. Two-year survival was 33% with ASA404 and 23% in the control group.

The company noted that previously-reported findings from the same trial have shown higher tumour response rates and “markedly higher” prostate-specific antigen response rates in patients on ASA404.

ASA404 is already in a late-stage trial for the first-line treatment of lung cancer and whether another Phase III study should be started for prostate cancer will be decided by Antisoma’s partner Novartis, which is “considering what the next steps should be”. Glyn Edwards, Antisoma’s chief executive, said that following the “very positive Phase II data” in lung cancer, “it does not surprise us to see further evidence of ASA404’s activity in prostate cancer”.

He added that “with its unique mode of action as a tumour-vascular disrupting agent, ASA404 has potential against a variety of solid tumours”. The compound will enter a second Phase III study in the second-line treatment of NSCLC later this year.