The company, which was working alongside Japan’s pharmaceutical company Eisai on the phase III-trial to study treatment for patients with Alzheimer’s, said the decision was based on an independent group’s analysis.
According to the analysis, the trials were not likely to “meet their primary endpoint”.
Biogen, one of the largest biotechs in the world, said the decision to stop the study was not based on safety concerns.
“This disappointing news confirms the complexity of treating Alzheimer’s disease and the need to further advance knowledge in neuroscience,” said CEO Michel Vounatsos. “We are incredibly grateful to all the Alzheimer’s disease patients, their families and the investigators who participated in the trials and contributed greatly to this research.
“Biogen’s history has been based on pioneering innovation, learning from successes and setbacks.”
Following the company’s announcement, which dashed hopes for sufferers of Alzheimer’s, Biogen’s stock fell more than 27 per cent in premarket trading Thursday to $234.
And the impact of the cancellation on the company’s market value could be more than $16bn, The Street estimates.
At the close of trading Wednesday, the company's market value had been $63bn.
Prior to the termination of the trial, Goldman Sachs analysts had projected sales of the drug could reach $12bn, CNBC reports.