Normally we are pleased to present news of medical breakthroughs in the battle against against prostate cancer. Almost weekly, it seems, advances in biochemistry, robotics and nanotechnology bring us closer to putting the whole disease under our thumb. But despite a daily drumbeat of steps moving forward, there is the occasional step back.

Back in October 2015, OncoGenx announced a phase 3 trial designed to evaluate whether the investigational treatment custirsen, when combined with cabazitaxel, improves survival in men with metastatic castrate-resistant prostate cancer (CRPC) whose disease has progressed following treatment with docetaxel.

The trial failed.

The international, randomized, open-label AFFINITY trial included 634 men with metastatic castrate-resistant prostate cancer whose disease progressed after treatment with docetaxel.

Patients received weekly cabazitaxel or prednisone with or without custirsen (OGX-011, OncoGenex). Treatment continued until disease progression, unacceptable toxicity or completion of 10 cycles.

The addition of custirsen conferred no significant OS benefit. Adverse events were consistent with those observed in previous trials of custirsen in metastatic castrate-resistant prostate cancer.

“We are obviously disappointed that custirsen was unable to demonstrate a survival benefit in prostate cancer. We would like to thank the patients who participated in the AFFINITY trial and their caregivers, as well as the investigators and their teams for their commitment to improving cancer care for patients who are in desperate need of new treatment options,” Scott Cormack, president and CEO of OncoGenex, said in a company-issued press release.

The final data will be submitted as a late-breaking abstract to the European Society for Medical Oncology Congress, which will be held in October in Copenhagen, Denmark.

OncoGenex plans to evaluate options with the FDA for an early analysis of the phase 3 ENSPIRIT trial, designed to investigate custirsen in combination with docetaxel as second-line chemotherapy in 700 patients with non–small cell lung cancer whose disease progressed after initial chemotherapy treatment.

“Given that the ENSPIRIT trial has nearly completed enrollment and we believe there are likely a sufficient number of events to determine the effect of custirsen in NSCLC, we are eager to expedite the final data analysis, which would allow us to conserve resources and fully understand the value of the asset as we evaluate our alternatives to maximize shareholder value,” Cormack said.