Biogen Receives European Commission Approval for High Dose Regimen of SPINRAZA® (nusinersen) for Spinal Muscular Atrophy

Rhea-AI Summary

Biogen (Nasdaq: BIIB) announced European Commission approval of a high dose regimen of SPINRAZA (nusinersen) for 5q spinal muscular atrophy on January 12, 2026. The regimen updates dosing to two 50 mg loading doses 14 days apart followed by 28 mg maintenance injections every four months, with a single 50 mg replacement for patients transitioning from 12 mg.

Approval is supported by DEVOTE Phase 2/3 data showing a CHOP-INTEND mean difference of 26.19 points (treatment-naïve infants) and HFMSE mean improvement of 1.8 points in transitioned patients; safety was generally consistent with the 12 mg regimen.

Positive

• EC granted marketing authorization for high dose SPINRAZA
• DEVOTE showed CHOP-INTEND mean difference of 26.19 points
• High dose regimen approved for treatment-naïve and transitioned patients
• Regimen aligns with existing intrathecal administration practices

Negative

• Most common AEs included pneumonia and COVID-19 at ≥10%
• Special warnings include thrombocytopenia, renal toxicity, hydrocephalus
• U.S. FDA decision on high dose is pending by April 3, 2026

News Market Reaction

-1.06%

1 alert

-1.06% News Effect

On the day this news was published, BIIB declined 1.06%, reflecting a mild negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

High dose loading: 50 mg/5 mL Maintenance dose: 28 mg/5 mL 5q SMA share: 95% of SMA cases +5 more

8 metrics

High dose loading 50 mg/5 mL SPINRAZA high-dose loading injection strength in EU approval

Maintenance dose 28 mg/5 mL SPINRAZA high-dose maintenance injection strength in EU approval

5q SMA share 95% of SMA cases Proportion of SMA represented by 5q spinal muscular atrophy

Patients treated more than 10,000 Infants, children, teens and adults treated with SPINRAZA worldwide since 2017

CHOP-INTEND difference 26.19 points Mean motor function difference vs matched sham in treatment-naïve infants

CHOP-INTEND change +15.1 vs -11.1 High-dose SPINRAZA vs sham CHOP-INTEND score change in DEVOTE

P-value p<0.0001 Statistical significance for CHOP-INTEND motor function improvement

HFMSE improvement 1.8 points Mean Hammersmith Functional Motor Scale – Expanded change to Day 302

Market Reality Check

Price: $172.62 Vol: Volume 1,400,073 is below...

low vol

$172.62 Last Close

Volume Volume 1,400,073 is below 20-day average 2,326,144 (relative volume 0.6) ahead of the news. low

Technical Price 187.62 is trading above the 200-day MA at 142.43, indicating a pre-existing uptrend into this EU approval.

Peers on Argus

BIIB was up 0.87% pre-news while key peers showed mixed, modest moves (e.g., BMY...

BIIB was up 0.87% pre-news while key peers showed mixed, modest moves (e.g., BMY +0.25%, PFE +0.55%, AMGN -0.82%, GSK -0.08%, SNY +0.51%). No clear, coordinated sector move is evident.

Historical Context

5 past events · Latest: Dec 22 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 22	ALS clinical data	Positive	-0.1%	Final Phase 3 VALOR and OLE QALSODY data showing slower ALS progression.
Dec 05	Epilepsy data update	Positive	-0.3%	Zorevunersen Phase 1/2a and OLE data showing seizure reductions in Dravet.
Dec 03	Alzheimer’s conference data	Positive	+0.6%	LEQEMBI maintenance data suggesting delayed progression in early Alzheimer’s.
Dec 02	Mechanism biomarker data	Positive	+0.3%	LEQEMBI CSF data confirming pharmacologic effect on Aβ protofibrils.
Dec 01	Epilepsy meeting preview	Positive	-2.4%	Announcement of upcoming zorevunersen presentations with long-term Dravet data.

Pattern Detected

Recent clinically-focused announcements often showed muted or negative next-day moves, even on positive data.

Recent Company History

Over the last several months, Biogen has reported multiple neurology-focused data updates. In late December 2025, final Phase 3 VALOR and OLE data for QALSODY in SOD1‑ALS showed slower functional decline and reduced risk of death or permanent ventilation, yet the stock moved only -0.06%. Earlier in December 2025, positive Dravet syndrome data for zorevunersen and multiple LEQEMBI Alzheimer’s disease datasets around CTAD 2025 produced mixed, largely modest price reactions. Today’s EC approval for a high-dose SPINRAZA regimen extends this pattern of significant neurology milestones with relatively contained immediate market responses.

Market Pulse Summary

This announcement grants European Commission approval for a high-dose SPINRAZA regimen for 5q SMA, w...

Analysis

This announcement grants European Commission approval for a high-dose SPINRAZA regimen for 5q SMA, which accounts for about 95% of SMA cases. The decision relies on Phase 2/3 DEVOTE data showing a 26.19‑point CHOP‑INTEND benefit and no new safety signals. Historically, Biogen’s neurology data and label expansions have produced mixed short-term market reactions, so investors may focus on real-world uptake, ongoing FDA review with a decision expected by April 3, 2026, and how this regimen supports the SMA franchise over time.

Key Terms

intrathecal, lumbar puncture, phase 2/3, open-label extension, +3 more

7 terms

intrathecal medical

"SPINRAZA is for intrathecal use by lumbar puncture by health care professionals"

Intrathecal describes a method of delivering a drug or therapy directly into the fluid-filled space around the spinal cord and brain so the medicine reaches the central nervous system more directly. For investors, intrathecal delivery matters because it often signals higher development complexity, specialized manufacturing and administration, and greater regulatory and safety scrutiny—factors that can affect costs, timelines and market adoption like choosing a specialist tool instead of a general one.

lumbar puncture medical

"for intrathecal use by lumbar puncture by health care professionals experienced"

A lumbar puncture is a medical procedure that collects cerebrospinal fluid from around the spinal cord by inserting a thin needle into the lower back; it’s used to diagnose infections, neurological conditions, or to deliver or test drugs directly to the central nervous system. For investors, this matters because lumbar punctures are often part of clinical trials and regulatory assessments; their need can influence trial design, patient enrollment, costs and timelines, acting like a diagnostic checkpoint that can speed or delay development.

phase 2/3 medical

"The EC approval is based on data from the three-part, Phase 2/3 DEVOTE study"

A phase 2/3 trial is a combined clinical study that first evaluates how well a treatment works and the best dose, then expands into a larger test to confirm those results and safety. For investors, it matters because moving into a phase 2/3 signals that an experimental therapy has shown initial promise and will be tested at scale, which can materially change the odds and timeline for regulatory approval and commercial potential.

open-label extension medical

"three-part, Phase 2/3 DEVOTE study and its ongoing long-term extension."

An open-label extension is a continuation of a clinical trial where all participants and researchers know which treatment is being given, often after an initial blinded phase. It allows further study of a drug's long-term safety and effectiveness. For investors, it can indicate ongoing interest and confidence in a product's potential, influencing perceptions of its future value.

Hammersmith Functional Motor Scale – Expanded medical

"mean improvement on the Hammersmith Functional Motor Scale – Expanded of 1.8 points"

A clinical rating tool that measures a patient’s ability to perform a set of everyday movements—sitting, standing, walking and other gross motor tasks—most often used for people with neuromuscular conditions like spinal muscular atrophy. For investors, it matters because scores are commonly used as primary outcomes in drug trials and regulatory decisions; a meaningful change is like a measurable improvement on a car’s dashboard that signals a therapy is working and can affect approval, market potential and revenue prospects.

adverse events medical

"the most common adverse events that occurred in at least 10% of participants"

Adverse events are any harmful or unwanted medical occurrences experienced by people using a drug, device, or undergoing a treatment, whether or not the problem is caused by the product. Think of them as complaints or breakdowns noticed during a trial or after a product is on the market; regulators record and investigate them. Investors care because clusters or serious adverse events can delay approvals, trigger costly studies or recalls, change labeling, and quickly alter a company’s revenue and risk profile.

hydrocephalus medical

"renal toxicity and hydrocephalus (excessive buildup of cerebrospinal fluid in the brain)."

A condition where excess cerebrospinal fluid accumulates inside the brain’s cavities, increasing pressure and potentially damaging brain tissue; think of it like a plumbing backup in a house that puts strain on the structure. It matters to investors because treatments, surgical devices, clinical trial results, regulatory approvals and long‑term care costs tied to this condition can affect the revenues and risks of medical device makers, drug developers, hospitals and insurers.

AI-generated analysis. Not financial advice.

• Approval is supported by data from the DEVOTE study which showed the benefit of the SPINRAZA 50 mg and 28 mg regimen in both treatment-naïve and previously-treated nusinersen patients with SMA¹
• Biogen is dedicated to partnering with the SMA community to advance care through scientific innovation and a commitment to enhancing outcomes for people living with SMA

CAMBRIDGE, Mass., Jan. 12, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (Nasdaq: BIIB) today announced the European Commission (EC) has granted marketing authorization for a high dose regimen of SPINRAZA^® (nusinersen) which is comprised of 50 mg/5 mL and 28 mg/5 mL doses for the treatment of 5q spinal muscular atrophy (SMA). 5q SMA is the most common form of the disease and represents approximately 95% of all SMA cases.² The SPINRAZA European Union marketing authorization has been updated to include the high dose regimen. The new high dose regimen comprises a more rapid loading phase, two 50 mg loading doses administered 14 days apart and 28 mg maintenance dose injections every four months thereafter. Individuals transitioning from the 12 mg dose will receive one 50 mg dose in place of their next 12 mg dose, followed by 28 mg maintenance doses every four months thereafter. SPINRAZA is for intrathecal use by lumbar puncture by health care professionals experienced in performing lumbar punctures.

“Since its approval in the European Union in 2017, SPINRAZA has helped set a new standard in patient care and treated more than then 10,000 infants, children, teens and adults worldwide,” Priya Singhal, M.D., M.P.H., Executive Vice President and Head of Development at Biogen. “We are proud to introduce the high dose regimen of SPINRAZA, which we have developed to address the evolving needs of individuals living with SMA, and are deeply committed to bringing it to the European SMA community as quickly as possible. We are grateful for all of the contributions of the SMA community who made today’s approval possible.”

The EC approval is based on data from the three-part, Phase 2/3 DEVOTE study and its ongoing long-term extension. Results from the pivotal cohort of the study showed treatment-naïve, symptomatic infants who received the high dose regimen of SPINRAZA experienced statistically significant improvements in motor function as measured by the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), when compared to a prespecified matched sham (untreated) group from the ENDEAR study* (mean difference: 26.19 points; +15.1 vs. -11.1, p<0.0001). Improvements in motor function were also observed in the open label cohort of individuals across a broad range of ages and SMA types who transitioned from the low dose regimen. These participants experienced a mean improvement on the Hammersmith Functional Motor Scale – Expanded of 1.8 points [SD 3.99] from baseline to Day 302.¹

“The DEVOTE results provide encouraging evidence that this new dosing option could deliver meaningful treatment outcomes with a safety profile generally consistent with the 12 mg dosing regimen,” said Eugenio Mercuri, M.D., Ph.D., Professor of Pediatric Neurology at the Catholic University, Rome, Italy. “I have witnessed the remarkable strides that have been made in treating SMA, but it is clear challenges remain. The European Commission approval of the high dose regimen of SPINRAZA is an important step toward addressing those challenges and advancing how we care for people living with SMA.”

Throughout the study, high dose regimen was generally well tolerated, with reported adverse events consistent with SMA and the known safety profile of nusinersen. No new safety concerns were observed with continued use of high dose nusinersen in the long-term-extension study. In the DEVOTE study, the most common adverse events that occurred in at least 10% of participants treated with the high dose regimen and occurred at least 5% more frequently than the matched sham group were pneumonia, COVID-19, pneumonia aspiration, and malnutrition.¹

Special warnings and precautions for use of nusinersen include adverse reactions as a part of the lumbar puncture procedure, low platelet counts and blood clotting abnormalities, renal toxicity and hydrocephalus (excessive buildup of cerebrospinal fluid in the brain).³

“As a community, we welcome advances that expand options for people living with SMA and reinforce continued innovation in SMA care,” said Nicole Gusset, CEO of SMA Europe. “This approval highlights the importance of sustained research and investment, contributing to a wider range of possibilities that may enable more tailored approaches to SMA care over time.”

The updated Summary of Product Characteristics will be available on the European Medicines Agency website at www.ema.europa.eu. 

The high dose regimen of SPINRAZA is also approved in Japan and is under review with the U.S. Food and Drug Administration (FDA) with a decision expected by April 3, 2026. Biogen is working with regulatory authorities around the world to progress this additional dosing option for people living with SMA. 

*ENDEAR is one of the two pivotal studies that formed the basis of regulatory approvals for SPINRAZA 12 mg.

About the DEVOTE Study¹
DEVOTE was a Phase 2/3 randomized, controlled, dose-escalating study designed to evaluate the safety, tolerability, pharmacokinetics and efficacy of SPINRAZA when administered at a higher dose (50/28 mg). The study enrolled 145 participants across ages and SMA types at approximately 42 sites around the world. DEVOTE included an open-label safety evaluation cohort (Part A), a double-blind, active control randomized treatment cohort (Part B), followed by an open-label treatment cohort (Part C) to assess the safety and tolerability of transitioning participants from the currently approved dose of SPINRAZA 12 mg to the higher dose regimen being tested in the study.

Part B was comprised of a pivotal cohort in treatment-naïve patients with infantile-onset SMA (n=75), and a supportive cohort in treatment-naïve patients with later-onset SMA (n=24). The primary endpoint of Part B measured the change from baseline on CHOP-INTEND at six months, comparing the high dose regimen of nusinersen to a matched, untreated sham control group from the Phase 3 ENDEAR study. ENDEAR is one of the two pivotal studies that formed the basis of regulatory approval for SPINRAZA 12 mg.

Part C was an open-label evaluation of the higher dose regimen in children and adults who transitioned from SPINRAZA 12 mg to the 50/28 mg regimen (n=40).

About SPINRAZA
The high dose regimen of SPINRAZA (nusinersen) which is comprised of 50 mg/5 mL and 28 mg/5mL injections are approved in the European Union and Japan to treat infants, children and adults with spinal muscular atrophy (SMA). The high dose regimen of nusinersen is currently under review with the U.S. Food and Drug Administration (FDA) with a decision expected by April 3, 2026. SPINRAZA 12 mg/5 mL injection is approved for SMA in more than 71 countries.⁴

The low dose regimen of SPINRAZA has shown efficacy across ages and SMA types with a well-established safety profile based on data in patients treated up to 10 years,^5,6 combined with unsurpassed real-world experience. The most common adverse events observed in clinical studies were respiratory infection, fever, constipation, headache, vomiting and back pain. Laboratory tests can monitor for renal toxicity and coagulation abnormalities, including acute severe low platelet counts, which have been observed after administration of some ASOs. 

Biogen licensed the global rights to develop, manufacture and commercialize SPINRAZA from Ionis Pharmaceuticals, Inc. (Nasdaq: IONS). For more information, visit your respective country's product website. For the U.S., please click here for Important Safety Information and full Prescribing Information .

About Biogen
Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients’ lives and to create value for shareholders and our communities. We apply deep understanding of human biology and leverage different modalities to advance first-in-class treatments or therapies that deliver superior outcomes. Our approach is to take bold risks, balanced with return on investment to deliver long-term growth.

We routinely post information that may be important to investors on our website at www.biogen.com. Follow us on social media - Facebook, LinkedIn, X, YouTube.

Biogen Safe Harbor
This news release contains forward-looking statements, including, among others, relating to: the potential benefits, efficacy and safety of higher doses of nusinersen (marketed as SPINRAZA); the potential to improve outcomes for, and address unmet needs of, patients with SMA; potential regulatory discussions, submissions, decisions and approvals and the timing thereof; the anticipated benefits, risks and potential of our collaboration arrangements; the potential of our commercial business and pipeline programs, including nusinersen; and risks and uncertainties associated with drug development and commercialization. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “forecast,” “goal,” “guidance,” “hope,” “intend,” “may,” “objective,” “outlook,” “plan,” “possible,” “potential,” “predict,” “project,” “prospect,” “should,” “target,” “will,” “would” or the negative of these words or other words and terms of similar meaning. Drug development and commercialization involve a high degree of risk, and only a small number of research and development programs result in commercialization of a product. Results in early-stage clinical trials may not be indicative of full results or results from later stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements. Given their forward-looking nature, these statements involve substantial risks and uncertainties that may be based on inaccurate assumptions and could cause actual results to differ materially from those reflected in such statements.

These forward-looking statements are based on management’s current beliefs and assumptions and on information currently available to management. Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part. We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to differ materially from those stated or implied in this document, including, among others, uncertainty of our long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; expectations, plans, prospects and timing of actions relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products; the potential impact of increased product competition in the biopharmaceutical and healthcare industry, as well as any other markets in which we compete, including increased competition from new originator therapies, generics, prodrugs and biosimilars of existing products and products approved under abbreviated regulatory pathways; our ability to effectively implement our corporate strategy; difficulties in obtaining and maintaining adequate coverage, pricing, and reimbursement for our products; the drivers for growing our business, including our dependence on collaborators and other third parties for the development, regulatory approval, and commercialization of products and other aspects of our business, which are outside of our full control; risks related to commercialization of biosimilars, which is subject to such risks related to our reliance on third-parties, intellectual property, competitive and market challenges and regulatory compliance; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; and the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; and any other risks and uncertainties that are described in reports we have filed with the U.S. Securities and Exchange Commission, which are available on the SEC’s website at www.sec.gov.

These statements speak only as of the date of this press release and are based on information and estimates available to us at this time. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and in our subsequent reports on Form 10-Q. Except as required by law, we do not undertake any obligation to publicly update any forward-looking statements whether as a result of any new information, future events, changed circumstances or otherwise.

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From time to time we have used, or expect in the future to use, our investor relations website (investors.biogen.com), the Biogen LinkedIn account (linkedin.com/company/biogen-) and the Biogen X account (https://x.com/biogen) as a means of disclosing information to the public in a broad, non-exclusionary manner, including for purposes of the SEC’s Regulation Fair Disclosure (Reg FD). Accordingly, investors should monitor our investor relations website and this social media channel in addition to our press releases, SEC filings, public conference calls and webcasts, as the information posted on them could be material to investors.

References:

1. Crawford TO, et al. Exploring Higher Doses of Nusinersen in Spinal Muscular Atrophy: Final Results From Parts B and C of the 3-Part DEVOTE Study. Presented at: World Muscle Society (WMS) Congress; 2024; Prague, Czechia.
2. Farrar MA, Kiernan MC. The Genetics of Spinal Muscular Atrophy: Progress and Challenges. Neurotherapeutics; 2015; 12:290–302.
3. European Medicines Agency. SPINRAZA Summary of Product Characteristics. Available at: https://www.ema.europa.eu/en/documents/product-information/spinraza-epar-product-information_en.pdf. Last accessed: December 2025.
4. Based on commercial patients, early access patients, and clinical trial participants through December 31, 2022. 
5. Core Data sheet, Version 13, October 2021. SPINRAZA. Biogen Inc, Cambridge, MA.
6. Finkel RS, et al. Final Safety and Efficacy Data From the SHINE Study in Participants With Infantile-Onset and Later-Onset SMA. Presented at: Cure SMA Conference; 2024; Austin, Texas.

MEDIA CONTACT: Biogen Madeleine Shin +1-781-464-3260 public.affairs@biogen.com

INVESTOR CONTACT: Biogen Tim Power +1 781 464 2442 IR@biogen.com

FAQ

What dosing does the SPINRAZA high dose regimen approved by the EC include for BIIB?

The regimen uses two 50 mg loading doses 14 days apart, then 28 mg maintenance injections every four months.

What were the key DEVOTE efficacy results supporting the EC approval of SPINRAZA (BIIB)?

DEVOTE reported a CHOP-INTEND mean difference of 26.19 points in treatment-naïve infants versus a matched sham group and HFMSE mean improvement of 1.8 points in transitioned patients.

Is the SPINRAZA high dose regimen considered safe compared with the 12 mg dose for BIIB?

Biogen reported the high dose safety profile was generally consistent with the 12 mg regimen and no new safety concerns in long-term extension.

When will the U.S. FDA decide on the SPINRAZA high dose application for BIIB?

A U.S. FDA decision is expected by April 3, 2026.

How will patients on 12 mg transition to the SPINRAZA high dose regimen for BIIB?

Patients transitioning from 12 mg receive one 50 mg dose instead of their next 12 mg dose, then 28 mg every four months.