Biogen Inc Stock Price, News & Analysis

Biogen (Nasdaq: BIIB) and Stoke Therapeutics presented longer-term open-label extension data for zorevunersen at the 54th Child Neurology Society Annual Meeting on Oct 9, 2025. Two‑year analyses showed continuing improvements in cognition and behavior versus minimal change in a two‑year natural history cohort. Clinician and caregiver Global Impression scales reported similar overall clinical improvements in 95% of patients (n=19) at three years. Substantial and durable reductions in major motor seizure frequency were observed through 36 months. Safety data (n=81) showed TEAEs in 30%–53%, CSF protein elevations in 14%–44% (any >50 mg/dL: 42%–86%), one discontinuation, and one SUSAR.

Biogen (NASDAQ: BIIB) and Eisai announced on October 6, 2025 that LEQEMBI IQLIK (lecanemab-irmb) subcutaneous 360 mg weekly maintenance dosing is now available in the U.S. for patients with early Alzheimer’s disease after an initial 18-month IV regimen. The approval follows FDA clearance in August 2025. Patients may continue IV infusions every four weeks or switch to the at-home autoinjector. The companies launched the LEQEMBI Companion program with nurse education, an app, a welcome kit, and a patient assistance program offering LEQEMBI at no cost for eligible patients.

Prescribing information highlights ARIA risks and recommends ApoE ε4 testing and MRI monitoring.

Biogen (NASDAQ:BIIB) and Eisai announced that their Alzheimer's treatment LEQEMBI® (lecanemab) has received approval in China for once-every-four-weeks intravenous maintenance dosing. This approval follows the initial January 2024 authorization for treating early Alzheimer's disease patients with mild cognitive impairment or mild dementia.

The maintenance dosing allows patients to transition from the initial bi-weekly 10 mg/kg dosing to a more convenient monthly schedule after 18 months of treatment. LEQEMBI is notable as the only approved therapy targeting both amyloid plaque and protofibrils, which can impact tau downstream. The market potential is significant, with an estimated 17 million patients with early-stage Alzheimer's in China as of 2024.

Biogen (NASDAQ:BIIB) and Eisai announced that Australia's Therapeutic Goods Administration (TGA) has approved LEQEMBI® (lecanemab) for the treatment of early Alzheimer's disease. The approval specifically targets adults with mild cognitive impairment or mild dementia who are either ApoEε4 non-carriers or heterozygous carriers.

The approval follows a review process initiated in March 2025 after an initial rejection in February 2025. LEQEMBI uniquely targets both toxic protofibrils and amyloid plaque, potentially impacting tau downstream. This approval is particularly significant as Australia faces growing dementia cases, with numbers expected to rise from 425,000 in 2024 to approximately 1,100,000 by 2065.

Biogen (NASDAQ:BIIB) received a Complete Response Letter (CRL) from the FDA regarding its supplemental New Drug Application for the high dose regimen of nusinersen in treating spinal muscular atrophy (SMA). The FDA requested updates to technical information in the Chemistry Manufacturing and Controls module, with no concerns cited about clinical data.

The company plans to promptly resubmit the application with readily available information. Notably, the high dose regimen was recently approved in Japan and is under review by the European Medicines Agency (EMA) and other global regulators.

Biogen (Nasdaq: BIIB) has announced its acquisition of Alcyone Therapeutics for an upfront payment of $85 million plus milestone payments. The acquisition centers on ThecaFlex DRx™, an implantable device designed for intrathecal delivery of antisense oligonucleotides (ASOs).

The device aims to provide an alternative to repeat lumbar punctures for chronic medicine administration, initially being evaluated with SPINRAZA® for spinal muscular atrophy patients. Biogen plans to launch the delivery system by early 2028, subject to clinical trials and regulatory approval.

As part of the deal, Alcyone's remaining assets will be divested into a new company, Neela Therapeutics. The transaction includes convertible debt financing in Neela from existing investors, including Biogen.

Biogen (NASDAQ:BIIB) has received European Commission (EC) approval for ZURZUVAE® (zuranolone), marking a significant breakthrough as the first and only treatment approved for postpartum depression (PPD) in Europe. The drug is administered as a once-daily, oral, 14-day treatment.

The approval is based on the successful SKYLARK study, which demonstrated significant reduction in depressive symptoms as early as day 3, with benefits sustained through day 45 compared to placebo. The study met its primary endpoint using the HAMD-17 depression severity scale at day 15.

This approval addresses a critical healthcare need, as up to 20% of European women experience PPD symptoms following pregnancy. ZURZUVAE has already received approvals in the U.S. (August 2023) and U.K. (August 2025).

Eisai and Biogen (NASDAQ:BIIB) have initiated a rolling Supplemental Biologics License Application (sBLA) to the FDA for LEQEMBI IQLIK, a subcutaneous autoinjector formulation of lecanemab-irmb, under Fast Track Status. This new formulation would allow at-home administration of LEQEMBI from the start of treatment for early Alzheimer's disease patients.

The autoinjector would enable a weekly starting dose of 500mg (two 250mg injections) as an alternative to bi-weekly intravenous dosing. Each injection takes approximately 15 seconds to administer. If approved, LEQEMBI IQLIK would be the first anti-amyloid treatment offering at-home injection from initiation through maintenance, potentially reducing healthcare resource utilization.

LEQEMBI is currently approved in 48 countries and under review in 10 others. The drug uniquely targets both amyloid plaque and protofibrils in Alzheimer's disease treatment.

Biogen (NASDAQ:BIIB) and Stoke Therapeutics presented promising data for zorevunersen, potentially the first disease-modifying treatment for Dravet syndrome, at the 36th International Epilepsy Congress. The Phase 1/2a and open-label extension studies showed significant results over three years, including:

Patients receiving 70mg doses demonstrated an 84.8% median reduction in seizures and gained eight additional seizure-free days per 28-day period. The drug showed durable efficacy with 77% (58/75) of patients remaining in the studies after three years, exhibiting sustained seizure reduction and improved quality of life.

Safety data from 81 treated patients showed zorevunersen was generally well-tolerated, with CSF protein elevations being the most common treatment-related adverse event. These results support the ongoing Phase 3 EMPEROR study.