Biogen (BIIB) Valuation in Focus After FDA Nod for At-Home Leqembi, Dravet Therapy Progress

Kshitija Bhandaru

Biogen (BIIB) has been making headlines after securing FDA approval for a new subcutaneous version of Leqembi, its Alzheimer’s treatment developed with Eisai. Unlike its previous formulations, this new option can be administered at home, potentially making ongoing care easier for patients and caregivers. In addition, Biogen’s late-stage clinical results with zorevunersen, developed in partnership with Stoke Therapeutics, point toward a real possibility of the first disease-modifying therapy for Dravet syndrome. These events are significant, and many investors are now wondering how they impact the company’s broader story.

The market’s reaction has been far from dull. Shares jumped 4.8% following the FDA’s green light for Leqembi’s new formulation, and positive zorevunersen data has only reinforced optimism around Biogen’s neurology-focused pipeline. Still, it’s worth remembering that over the past year, Biogen stock remains down nearly 30%, with some long-term holders weathering even steeper declines. The company’s recent momentum appears to mark a shift from what has been a challenging few years, as the stock has struggled to regain its footing despite clinical wins and approvals.

As Biogen appears to be turning a corner, some investors are considering whether there is real value to be found or if the market has already accounted for the company’s next stage of growth.

Most Popular Narrative: 18% Undervalued

According to the most widely followed narrative, Biogen is considered significantly undervalued, with its fair value estimated to be notably above the current market price. This narrative is built on the expectation of expanding access to therapies, ongoing drug launches, and operational efficiency gains.

Demand for Biogen's Alzheimer's therapy LEQEMBI is poised for structural long-term growth, supported by a rapidly aging global population and accelerating rates of mild cognitive impairment diagnoses. These developments are facilitated by breakthroughs in blood-based biomarkers and expanding diagnostic infrastructure. These factors position Biogen to capture a larger patient pool and drive sustained revenue expansion.

Curious what drives analysts to value Biogen so much higher than today’s price? The heart of this narrative is the projected financial turnaround, shaped by bold assumptions about future earnings, margins, and global sales momentum. Wondering which overlooked metrics and future launches might cause a market re-rating? Find out how these quantitative forecasts and unique business advantages set the stage for substantial upside.

Result: Fair Value of $171.96 (UNDERVALUED)

Have a read of the narrative in full and understand what's behind the forecasts.

However, accelerating competition and setbacks in new product launches could quickly challenge bullish assumptions and prompt a reassessment of Biogen’s valuation.

Find out about the key risks to this Biogen narrative.

Another View: Our DCF Model’s Perspective

Looking at Biogen through the lens of our SWS DCF model provides a different angle and also suggests undervaluation based on future cash flows. Can this approach offer extra confidence for cautious investors?

Look into how the SWS DCF model arrives at its fair value.
BIIB Discounted Cash Flow as at Sep 2025
Simply Wall St performs a discounted cash flow (DCF) on every stock in the world every day (check out Biogen for example). We show the entire calculation in full. You can track the result in your watchlist or portfolio and be alerted when this changes, or use our stock screener to discover undervalued stocks based on their cash flows. If you save a screener we even alert you when new companies match - so you never miss a potential opportunity.

Build Your Own Biogen Narrative

If you find yourself questioning these conclusions or want to dive deeper on your own, you can piece together a custom outlook in just minutes: Do it your way.

A great starting point for your Biogen research is our analysis highlighting 3 key rewards and 1 important warning sign that could impact your investment decision.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.

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