A Phase III trial of custirsen in combination with cabazitaxel and prednisone in patients with previously treated metastatic, castration-resistant prostate cancer showed no significant survival gains when compared to cabazitaxel and prednisone alone.

Researchers saw no significant difference in overall survival between the custirsen and placebo arms of the study, with medians of 14.2 months and 13.4 months, respectively. The trial, which enrolled 635 patients previously treated with docetaxel, also reported similar results between the two arms in overall survival, and in the number of patients who discontinued treatment due to progressive disease or adverse events. The findings were presented at the annual congress of the European Society for Medical Oncology.

A previous Phase II trial of custirsen, developed by OncoGenex Pharmaceuticals, combined with chemotherapy suggested it may lead to improved clinical outcomes, and an earlier Phase III trial of custirsen in combination with docetaxel suggested patients with more aggressive cancers may benefit from the combination.