** Drug developer's shares down 7 pct at $6.28
** Credit Suisse halves price target to $10, saying it does not expect data from mid-stage trial of prostate cancer drug to be conclusive to support a late-stage trial
** Company's lead drug met the main goal in a mid-stage trial in lung cancer patients.
** Credit Suisse expects data from mid-stage study of the same drug in prostate cancer patients towards year-end or early 2015
** Median price target on stock $20
** Up to Wednesday's close, stock had lost 55 pct this year