CHICAGO (Reuters) -- An experimental blood clot dissolver by Nuvelo Inc. and its German partner Bayer failed to meet its main goal in two late-stage studies, sending the U.S. biotechnology company's shares down more than 79 percent Monday.
Nuvelo (down $15.50 to $4.05) shares closed at $4.05, down $15.50.
The companies said they had temporarily suspended enrollment in all trials of the alfimeprase compound pending further analysis and discussions with outside experts and regulatory agencies.
The news rattled investors, who had high hopes for the drug.
"We are very surprised by these results, given the strength of the prior (midstage) results," said CIBC analyst Bret Holley in a note to clients.