Shares of Exelixis (NASDAQ:EXEL) plummet 49% premarket on light volume in response to the company's disclosure that its prostate cancer drug candidate, cabozantinib, failed to demonstrate a statistically significant increase in overall survival (OS) compared to prednisone. The median OS for the cabozantinib cohort was 11.0 months versus 9.8 months for the prednisone arm (hazard ratio = 0.90; 95% confidence interval; p value = 0.212).
Median progression-free survival (PFS) was 5.5 months for the cabozantinib arm versus 2.8 months for the prednisone arm (hazard ratio = 0.50; 95% confidence ration; p value = 0.0001).
Exelixis will initiate a workforce reduction of ~70% (160 employees) and will take a $6M - 8M restructuring charge.
The clinical development of cabozantinib for metastatic castration-resistant prostate cancer has been deprioritized and the second privotal trial evaluating pain palliation in prostate cancer has been halted.