Biogen Inc. (NASDAQ: BIIB) announced that the European Commission (EC) has granted marketing authorization for a high‑dose regimen of SPINRAZA (nusinersen) for the treatment of 5q spinal muscular atrophy (SMA), representing approximately 95% of all SMA cases. The approval follows a Complete Response Letter (CRL) from the U.S. FDA in September 2025, with a final U.S. decision expected by April 3 2026.
Regulatory Milestone
Item
Detail
Regulatory Authority
European Commission (EU)
Product
SPINRAZA (nusinersen) High‑Dose Regimen
Dosage Forms
50 mg/5 mL and 28 mg/5 mL
Indication
5q spinal muscular atrophy (SMA)
Approval Date
12 Jan 2026
U.S. Status
CRL received Sep 2025; FDA decision due Apr 3 2026
Japan Status
High‑dose regimen already approved
Drug Profile & Dosing Regimen
Mechanism:Antisense oligonucleotide that increases SMN protein production by modifying SMN2 pre‑mRNA splicing
High‑Dose Regimen:
Loading Phase: Two 50 mg doses administered 14 days apart (vs. five 12 mg doses over 14+64 days)
Maintenance:28 mg injections every 4 months (vs. 12 mg every 4 months)
Transition: Patients on 12 mg regimen receive one 50 mg dose in place of next 12 mg dose, then switch to 28 mg maintenance
Rationale: Higher loading dose aims for faster motor function improvements and more durable SMN protein elevation
Clinical Evidence – DEVOTE Study
Cohort
Population
Primary Endpoint
Result
Comparator
Pivotal Cohort
Treatment‑naïve symptomatic infants (n = 59)
CHOP‑INTEND motor function at 6 months
Statistically significant improvement (p < 0.001) vs. sham
Matched sham group from ENDEAR study
Open‑Label Cohort
Broad age/SMA types transitioning from 12 mg (n = 48)
CHOP‑INTEND change from baseline
Mean +8.5 points at 6 months
Historical low‑dose controls
Long‑Term Extension
All DEVOTE participants
Safety & durability
Sustained improvements through 12 months
Ongoing
Safety
All treated patients (N = 107)
Grade ≥ 3 TEAEs
18 % (consistent with SMA disease/nusinersen profile)
No new safety signals
Study Design: Three‑part Phase 2/3 DEVOTE study with ongoing long‑term extension
Key Finding: High‑dose regimen achieved faster onset of action and greater magnitude of motor improvement vs. historical low‑dose data
Market Opportunity & Strategic Outlook
Parameter
2026E
2027E
2028E
Global SMA Market
$1.85 billion
$2.1 billion
$2.35 billion
5q SMA Share
95 %
95 %
95 %
EU Market Size
$420 million
$460 million
$490 million
High‑Dose SPINRAZA EU Launch
Q2 2026
Full rollout
Market penetration
Peak EU Market Share
–
35 %
42 %
Peak EU Revenue
–
$161 million
$206 million
Unmet Need:15‑20 % of patients on low‑dose SPINRAZA plateau in motor function; high‑dose offers rescue option
Pricing: EU high‑dose price estimated at +30 % premium over 12 mg (€125,000 vs. €96,000 per loading phase)
Japan Approval: High‑dose approved in 2025; reimbursement secured at comparable premium
U.S. Outlook: CRL requested additional CMC details and IV administration feasibility data; Biogen resubmission expected Q1 2026
High‑dose SPINRAZA targets maintenance population and non‑responders – complementary positioning
Strategic Positioning
Manufacturing: High‑dose formulation produced at Biogen’s Solothurn, Switzerland facility; no new capacity required
Patent Extension: High‑dose regimen extends EU patent protection to 2039 (vs. 2034 for 12 mg) via new dosing regimen patent
Patient Conversion: Biogen launching switch program for existing patients; estimated 25 % conversion by 2027 , generating €80 million incremental revenue without new patient acquisition
Pipeline Synergy: High‑dose data may support similar regimen for BIIB115 (next‑generation antisense) in development
Forward‑Looking Statements This brief contains forward‑looking statements regarding SPINRAZA high‑dose commercial performance, FDA approval timeline, and competitive positioning. Actual results may differ due to regulatory decisions, pricing negotiations, and gene therapy adoption rates.-Fineline Info & Tech
By Fineline Cube 