The release of clinical trial data can be make-or-break moments for biotech companies. Three companies, Exelixis (NASDAQ:EXEL), Vertex Pharmaceuticals (NASDAQ:VRTX), and Prana Biotechnology (NASDAQ: PRAN) are finishing up trials, and should release data shortly.

Exelixis' trials, dubbed Comet 1 and Comet 2, will measure Cometriq's ability to increase survival and decrease pain associated with bone metastasis in patients with prostate cancer. Cometriq is already approved to treat thyroid cancer, but the prostate cancer data, which will read out later this year, could increase the drug's market substantially.

Vertex is also testing a drug that's already been approved, Kalydeco, but the biotech is combining Kalydeco with another drug from its pipeline, VX-809, in patients with cystic fibrosis. If the two trials -- Traffic and Transport -- are positive, Vertex will be able to treat a larger portion of cystic fibrosis patients than those who respond to Kalydeco alone.

Finally, Prana Biotechnology has said it will release data for its drug PBT2 in patients with Alzheimer's disease this month.

Watch the video below for a full take on the trials and predictions from Fool contributor Brian Orelli and health-care bureau chief Max Macaluso.

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