Trading in Biogen (BIIB) - Get Report was halted Friday ahead of a U.S. Food and Drug Administration advisory committee meeting on the drugmaker's experimental Alzheimer's disease treatment, aducanumab.
The FDA panel of outside advisers will discuss whether aducanumab is an effective treatment for Alzheimer's disease and whether to recommend clearance of the drug.
The FDA does not have to follow the advice of an advisory committee, but it typically does.
The panel has been the source of some controversy after the FDA recused a member, citing conflict of interest.
Mayo Clinic neurologist David Knopman confirmed to Reuters on Monday that he had been recused from the scheduled meeting.
Knopman, who said he was recused because of his involvement in conducting clinical trials of aducanumab, has criticized the drug, including in a paper published Sunday in the journal Alzheimer's & Dementia, Reuters reported.
Biogen shares had soared on Wednesday after an FDA panel said aducanumab had been found effective enough in a large trial to support approval.
The effect of the drug is “robust and exceptionally persuasive” in one study, FDA staff said Wednesday, according to Bloomberg.
If approved, aducanumab might be a multibillion-dollar seller, analysts told Reuters. The FDA hasn’t reviewed an application for a new Alzheimer’s treatment since 2003.
Aducanumab is important to Biogen. Last month the company lowered its full-year guidance, saying that generic versions of its Tecfidera multiple-sclerosis treatment had cut into sales.
Biogen has said aducanumab was shown in one of two major studies to significantly slow the decline of cognition and functions.
A second trial, however, showed a benefit only for a subset of patients who were given a high dose for at least 10 months, Reuters said.
Biogen halted clinical trials on the drug in March 2019 after determining that aducanumab was unlikely to work. It reversed course in October after reviewing more data and it declared that one of the two trials had been successful.
Biogen is jointly developing the drug with the Japanese pharmaceutical company Eisai (ESALY) .
Biogen stock closed Thursday down 7.5% at $328.90.