Why Exelixis (EXEL) Stock Plunged to a One-Year Low Today

NEW YORK (TheStreet) -- Shares of Exelixis  (EXEL) plummeted to a 52-week low of $1.85 in Tuesday trading after the drug developer announced its potential prostate cancer treatment cabozantinib did not prolong survival in subjects with advanced prostate cancer in a Phase III trial.

The study focused on 960 men with advanced prostate cancer who were no longer responsive to the chemotherapy drug docetaxel, Johnson & Johnson's  (JNJ) drug Zytiga or Medivation's  (MDVN) Xtandi. The trial randomly treated patients with cabozantinib or the steroid prednisone and observed the effects on survival rate. Cabozantinib reduced death risk by 10% compared to the steroid but did not show a statistically significant difference. The study did not reach its primary endpoint.

Exelixis announced it would fire 70% of its employees, or 160 workers, due to the poor results. The company will now employ 70 people and work on two ongoing phase III studies of cabozantinib in kidney cancer and liver cancer. The FDA has already approved the drug, sold as Cometriq, to treat a form of thyroid cancer.

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EXEL Chart EXEL data by YCharts

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