Biogen surges 40% after stunning reversal sees it revive plans for Alzheimer's treatment

• Shares of Biogen surged more than 40% on Tuesday morning after the company announced plans to seek approval for an experimental Alzheimer's treatment called aducanumab.
• Investors welcomed the news after the company's shares plummeted 29% in March when Biogen said it would abandon the therapy following two failed clinical trials.
• The company said it decided to revisit submitting the therapy for approval following a new analysis of the data from the failed trials and a series of discussions with the Food and Drug Administration.
• Watch Biogen trade live on Markets Insider.

Biogen's stock price charged more than 40% higher on Tuesday morning after the company said it would submit an Alzheimer's treatment for regulatory approval.

The biotechnology company made the decision to revive the experimental therapy called aducanumab following a new analysis of data from failed clinical trials and a series of discussions with the Food and Drug Administration.

"We are hopeful about the prospect of offering patients the first therapy to reduce the clinical decline of Alzheimer's disease and the potential implication of these results for similar approaches targeting amyloid beta," Biogen CEO Michel Vounatsos said in a press release.

The treatment was almost abandoned in March after its major clinical trial was written-off as a failure - a development that sent shares plunging 29% in a single session.

But after another review of a larger dataset from the trial Biogen said the treatment showed promising results.

"Patients who received aducanumab experienced significant benefits on measures of cognition and function such as memory, orientation, and language," the company said in a press release.

The therapy also appeared to improve patients' ability to do daily activities such as cleaning, shopping, and doing laundry, Biogen said.

After conferring with the FDA, Biogen intends to file an application for the treatment in early 2020.

Shares of Biogen were down 26% year-to-date through Monday's close.

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