Statement21 Jun 2016 00:18
That prompted the firm's shares to fall 66 percent, a move which Woodford said was overdone.
"We would expect an announcement like this to be greeted by a share price decline but it is the nature of the stock market to over-react to negative news, with the immediate reaction typically much greater than long-term fundamentals would justify," Woodford said in a blog post on his firm's website.
"That is almost certainly the case here - this is a significant disappointment for Circassia but we remain supportive shareholders and from here, we continue to see long-term value in the shares." (Reporting by Simon Jessop; editing by Carolyn Cohn)