Biogen Inc (NASDAQ:BIIB) failed to win the backing of the FDA panel which reviewed the BLA for its controversial Alzheimer's drug aducanumab, an antibody which targets amyloid-beta.

The FDA panel also voted 0-7 on the question of whether Study 103 provided supportive evidence of the effectiveness of aducanumab for the treatment of Alzheimer's disease. Four members abstained from voting.

A briefing document made available Wednesday raised hopes for a favorable verdict, given its positive take on efficacy and safety and the acknowledgment that there is a significant unmet need.

Related Link: Attention Biotech Investors: Mark Your Calendar For These November PDUFA Dates

What Next? The FDA has set a PDUFA goal date of March 7, 2021, for the aducanumab BLA.

The regulatory agency takes into account Adcom recommendations but is not bound to toe in line.

It may be noted that Sarepta Therapeutics Inc's (NASDAQ:SRPT) Duchenne muscular dystrophy drug Exondys 51 was approved by the FDA in 2016 after an FDA panel voted against approving the drug.

Given the pressure to have a drug on the market for Alzheimer's, the FDA could throw caution to the wind and issue conditional approval for aducanumab.

Biogen has a lot riding on aducanumab approval, which is touted to possess blockbuster potential. The company may now have to spend a nervous four-month period before it gets to know about the fate of the drug.

BIIB Price Action: Biogen shares skyrocketed about 44% to $355.63 Wednesday in reaction to the favorable briefing document. Other biopharma companies working on neurological disorders, including Eli Lilly And Co (NYSE:LLY), had also moved higher in sympathy.

Biogen was halted before Friday's open, last trading at $328.90 per share.