Should New LEQEMBI Data and Subcutaneous Option Shift the Risk Profile for Biogen (BIIB) Investors?

• In late November and early December 2025, Eisai and Biogen reported new LEQEMBI (lecanemab) data at the CTAD conference, highlighting long-term “time savings” in Alzheimer’s progression and bioequivalent efficacy and safety for a newly approved subcutaneous maintenance formulation versus the existing intravenous regimen, alongside fresh biomarker evidence from cerebrospinal fluid studies.
• These findings suggest that earlier and continuous LEQEMBI treatment could meaningfully extend the time patients remain in milder disease stages while a more convenient subcutaneous option may improve real-world treatment uptake and persistence.
• We’ll now examine how LEQEMBI’s long-term progression data and subcutaneous formulation, presented at CTAD, could influence Biogen’s investment narrative.

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Biogen Investment Narrative Recap

To own Biogen, you generally need to believe that a handful of newer products, with LEQEMBI at the center, can offset pressure in the mature MS and biosimilars-exposed portfolio. The CTAD data on long term “time savings” and the bioequivalent subcutaneous regimen reinforce LEQEMBI’s role in that thesis, but do not remove the near term risk that Alzheimer’s uptake, reimbursement and competition could fall short of expectations.

Among recent announcements, Biogen’s research collaboration with Dayra Therapeutics on oral macrocyclic peptides is the most relevant outside Alzheimer’s. While still early, it shows Biogen looking to build a broader immunology pipeline that could eventually complement or backstop LEQEMBI and other key launches, which is important given how concentrated the growth story currently is.

Yet while LEQEMBI’s data strengthen one pillar of the story, investors should also be aware of growing pricing and reimbursement pressures on high cost specialty drugs that...

Read the full narrative on Biogen (it's free!)

Biogen's narrative projects $9.4 billion revenue and $2.1 billion earnings by 2028.

Uncover how Biogen's forecasts yield a $178.07 fair value, in line with its current price.

Exploring Other Perspectives

Seven members of the Simply Wall St Community currently value Biogen between US$100 and about US$369 per share, showing very different expectations for what the business is worth. Against that wide range, the heavy reliance on a few new launches, especially LEQEMBI, gives those varied views real consequences for how you think about Biogen’s future performance.

Explore 7 other fair value estimates on Biogen - why the stock might be worth 45% less than the current price!

Build Your Own Biogen Narrative

Disagree with existing narratives? Create your own in under 3 minutes - extraordinary investment returns rarely come from following the herd.

• 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.
• Our free Biogen research report provides a comprehensive fundamental analysis summarized in a single visual - the Snowflake - making it easy to evaluate Biogen's overall financial health at a glance.

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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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