Biogen Inc.’s experimental Alzheimer’s treatment met the main goal of a pivotal trial on Tuesday.
But the results weren’t quite what the company had hoped. The effectiveness was limited to mild patients, not the double-digit percentages that Biogen had previously predicted.
Biogen’s shares fell as much as 3.3 percent to $243.36 in extended trading after the study results were released.
The Bethesda, Maryland-based company in early January had touted its statistical superiority, as more patients treated with its drug Abadev with no biological indications of Alzheimer’s disease experienced cognitive decline than those given a placebo. The number of patients treated rose to 407 from 268 at the study’s end in December.
The glimmers of potential good news that appeared last year have faded for the latest blowup of the latest, most costly and uncertain breakthrough in Alzheimer’s disease treatment. Investors are currently anxiously awaiting results of another trial at the end of April from Novartis AG.
Biogen had planned to complete the study as soon as late 2016, but it made some technical changes based on positive data from a different trial, delaying it. It also decided to do a larger trial compared with the two smaller trials, testing the impact on the brains of patients with the earliest stages of Alzheimer’s. That effort includes patients who go on to develop Alzheimer’s disease within years, not years of therapy.
It’s unclear yet how these trial results will impact the status of Abadev, or whether Biogen will continue the drug’s development.
Biogen Chief Executive Officer Michel Vounatsos said in a statement on Tuesday that the company was ready to move forward with those plans. The original trial included 3,101 patients, and Biogen said that the new trial had in excess of 900 patients.
“This trial should give us a perspective on the potential long-term benefit of the molecule in a wider group of patients with early Alzheimer’s,” Vounatsos said.