OncoGenex, Teva flag a failed PhIII for prostate cancer drug

Shares of OncoGenex ($OGXI) went into meltdown mode this morning after the biotech and its partner Teva ($TEVA) put out word that their experimental prostate cancer drug had flunked a long-awaited Phase III study. Shares of OncoGenex immediately shed more than half their value in the reckoning with investors.

A combination of custirsen and docetaxel barely edged out docetaxel alone for the rate of overall survival--23.4 months versus 22.2 months--for castration-resistant patients with metastatic disease. Those kinds of numbers could signal the death knell for this program, which is still pursuing another Phase III study of the drug in combination with Jevtana.

Two years ago OncoGenex and Teva significantly upped the ante for this program, axing a planned study while expanding its Synergy study from 800 to 1,000 patients. Their failure follows big successes from J&J ($JNJ) for Zytiga and Medivation's ($MDVN) Xtandi (partnered with Astellas), which have helped transform treatment options for the disease, making it more difficult for any new entries to the field.

Teva invested $60 million in OncoGenex when it partnered with the biotech back in 2009. The Israeli company, which has been struggling to find new drugs, also committed to $370 million in milestones and covered development costs.

OncoGenex is based in Bothell, WA, with facilities in Vancouver.

"The results of SYNERGY are unexpected, particularly given the wealth of scientific evidence supporting the targeting of clusterin to combat treatment resistance in first-line prostate cancer," said OncoGenex CEO Scott Cormack in a statement. "A thorough analysis of the data is underway to understand the potential factors that may have contributed to the results. Importantly, we remain strong in our belief that targeting mechanisms of treatment resistance is a critical path forward in the fight against cancer and we continue to actively pursue this approach through the two ongoing Phase III trials of custirsen and the 7 Phase II trials of apatorsen in four tumor types."

- here's the release