Correction: A previous version of this story stated incorrectly that 75% of the pancreatic cancer patients enrolled in the NewLink Genetics phase III study died. The story has been corrected to say that 75% of the 444 patient deaths required to reach the final analysis of the study has occurred.
NEW YORK ( TheStreet) -- More than three-quarters of the required deaths among pancreatic cancer patients enrolled in NewLink Genetics (NLNK) phase III study have been recorded but the company's experimental therapeutic vaccine is still unable to demonstrate a survival benefit significant enough to declare victory.
The odds are now higher that NewLink's HyperAcute pancreas vaccine will prove to be a failure once a final survival analysis is conducted later this year or in early 2016. NewLink tried to put a positive spin on the outcome from the study's second, interim analysis, but investors didn't share the optimism.
In pre-market trading on Tuesday, NewLink shares were down 21% to $41.
NewLink supporters will no doubt defend HyperAcute by claiming that cancer vaccines take longer to generate an immune response, which then requires longer follow-up to demonstrate a survival benefit. The problem with the explanation is that half the 722 pancreatic cancer patients enrolled in NewLink's study aren't being treated with HyperAcute, and so they shouldn't be living any longer than expected.
But these control-arm patients are living longer. If they weren't -- and HyperAcute was even moderately effective -- the study would have stopped already with a positive survival benefit.