Biogen Inc. stock gains regulatory boost from Japan approval for Leqembi Pen

Published on 09/19/2026 at 10:15 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Biogen Inc. stock closed at USD 215.50 on Nasdaq on September 18, 2026, after Japan approved the subcutaneous Leqembi Pen formulation for early Alzheimer’s disease. In Q2 2026, Biogen’s total revenue rose 3% year over year to USD 2.7 billion, underpinned by a 24% surge in its growth portfolio.

Fotorealistisches Biotech-Labor in Cambridge MA mit Forscherin am Mikroskop und Blick auf den Charles River — Biogen Inc. Neurowissenschaftslabor in Cambridge MA zeigt Forscherin bei Gehirngewebeanalyse unter Mikroskop ISIN US09062X1037, Illustration mit AI erstellt.

Biogen Inc. stock (ISIN US09062X1037) closed at USD 215.50 on Nasdaq on September 18, 2026, down 1.62% from the prior session, as investors digested fresh regulatory news from Japan on the company’s Alzheimer’s drug Leqembi Pen.

Japan approves subcutaneous Leqembi Pen

According to JCN Newswire on September 18, 2026, Eisai and Biogen announced that the subcutaneous formulation Leqembi Pen has been approved in Japan for the treatment of early Alzheimer’s disease, adding a more convenient administration route alongside the existing intravenous form.

The companies highlighted that the new Leqembi Pen uses the same anti-amyloid beta protofibril antibody lecanemab as the original product, but the ability to deliver it subcutaneously could broaden usage among patients who prefer shorter clinic visits or have limited access to infusion centers, which investors view as a strategic expansion of Biogen’s neurology franchise.

Q2 2026 figures show growth portfolio outpacing legacy business

As Quantfury reports, Biogen generated total revenue of USD 2.7 billion in the second quarter of 2026, a 3% increase compared with the same period a year earlier, underlining that its newer therapies are starting to offset pressure in multiple sclerosis.

In the same Q2 2026 period, revenue from Biogen’s designated growth portfolio of neurology and rare disease drugs rose 24% to nearly USD 1.06 billion, clearly outpacing the legacy multiple sclerosis portfolio and signaling a shift in the company’s revenue mix toward newer assets.

Stock performance and valuation context

The MarketBeat biotech comparison table shows Biogen Inc. stock trading at USD 215.50 at the regular-session close on Nasdaq on September 18, 2026, with the quote attributed to 4:00 p.m. Eastern Time, and an after-hours indication of USD 217.00 at 7:58 p.m. Eastern, suggesting modest buying interest after the Leqembi Pen approval news.MarketBeat

A separate overview places Biogen’s market capitalization at about USD 31.841 billion as of September 18, 2026, positioning the company as a large-cap biotech player within the broader drug manufacturers segment.Yahoo Finance

Upcoming catalysts and investor focus

In its discussion of Biogen’s strategy, Quantfury notes that management expects revenue to rise by a mid single-digit percentage in 2026, after previously forecasting in April that revenue would fall by a similar magnitude, indicating a guidance shift as Leqembi and other growth-portfolio drugs gain traction.

Quantfury also points out that Biogen shares rose about 50% over the past year for a company valued at around USD 39 billion in that comparison, underscoring how optimism about its Alzheimer’s franchise and growth portfolio has already been partly reflected in the stock price.Quantfury

Biogen Inc. stock and closing price

Per the Nasdaq quote referenced by MarketBeat, Biogen Inc. stock finished the September 18, 2026 trading session at USD 215.50 on Nasdaq, down 3.55 dollars or 1.62% on the day, with an after-hours level of USD 217.00, giving investors a clear benchmark for the stock’s reaction around the time of the Leqembi Pen approval in Japan.