Shares of OncoGenex Pharmaceuticals (NASDAQ: OGXI) were crushed today, after the company's most advanced drug candidate, Custirsen, flopped in a phase 3 trial.

The drug did not improve median overall survival, the primary endpoint of its late-stage trial in patients with metastatic castration-resistant prostate cancer (or CRPC), in a statistically significant way. When taken in combination with prednisone and docetaxel, Custirsen helped generate median overall survival of 23.4 months, as compared to 22.2 months for patients taking prednisone and docetaxel only.

OncoGenex has Custirsen in late-stage trials for several other indications and another drug candidate, Apatorsen, in mid-stage trials (some of which are due to read out later this year). So, should investors consider the massive drop an opportunity to get shares at a cheaper price? In the video below, Motley Fool health care analysts David Williamson and Michael Douglass answer.