Biogen (NASDAQ: BIIB) is a US biotechnology company anchored in the Alzheimer's disease space through its partnership with Eisai on LEQEMBI (lecanemab), a humanized IgG1 monoclonal antibody selective for amyloid protofibrils. LEQEMBI received full FDA approval in July 2023 for early Alzheimer's disease and reached the subcutaneous autoinjector maintenance-dosing formulation with LEQEMBI IQLIK in August 2025. At AAIC 2026 (July 12-15, London), Eisai and Biogen presented additional SC autoinjector data supporting a fully SC treatment pathway from initiation through maintenance, plus real-world LEADER Study data showing 75.9% of 432 early Alzheimer's patients remained stable and 6.6% improved over an average 17 months of treatment.
Biogen's proprietary tau program is diranersen (BIIB080), an intrathecally administered antisense oligonucleotide (ASO) targeting MAPT RNA. Phase 2 CELIA study data presented at AAIC 2026 on Tuesday July 14 showed the drug missed its primary endpoint of dose response on CDR-SB at Week 76, but delivered strong reductions in tau pathology across all three studied doses and slowing of cognitive decline particularly at the lowest dose. Biogen plans to advance diranersen to registrational Phase 3 development, positioning it as the first tau-directed therapy to show both biomarker impact and cognitive benefit in a randomized Phase 2 trial.
Stories here cover Biogen trial readouts, LEQEMBI commercial milestones, and the tau franchise. See [[eisai]], [[lecanemab]], [[diranersen]], and [[tau]] for adjacent threads.
Eisai (TSE: 4523) and Biogen (NASDAQ: BIIB) announced Wednesday August 26, 2026 that once-weekly subcutaneous lecanemab-irmb (brand name Leqembi Iqlik) is now commercially available in the United States for initiation therapy in adults with early Alzheimer's disease (AD). Approved patient population: adults with mild cognitive impairment (MCI) or mild dementia due to AD, the same patient population that was approved for the IV formulation. Mechanism: lecanemab is a humanized IgG1 monoclonal antibody targeting soluble amyloid-beta protofibrils and preventing their aggregation into amyloid plaques that drive Alzheimer's pathology. Delivery format shift: the US launch represents the anti-amyloid class's substantive transition from the existing twice-monthly IV infusion format (requiring 1 hour of infusion time plus monitoring) to a weekly subcutaneous injection that substantially improves patient accessibility and reduces the infrastructure burden that has constrained the ongoing global Leqembi launch. Practical impact on Leqembi commercial trajectory: the SC format removes several barriers including infusion center scheduling constraints, long chair time per dose, and IV line placement complications. Eisai and Biogen have been struggling with slower-than-expected Leqembi launch since initial 2023 FDA approval due to reimbursement complexity, MRI monitoring requirements for amyloid-related imaging abnormalities (ARIA), and infrastructure requirements; the SC availability addresses one substantive barrier. Q2 2026 Leqembi worldwide sales reached roughly $340 million; the SC transition is expected to accelerate the commercial trajectory in Q4 2026 and into 2027.
Biogen (NASDAQ: BIIB) and Chinese partner TJ Biopharma announced Monday August 17, 2026 that felzartamab for injection (branded Jingfei in China), an anti-CD38 monoclonal antibody, has been approved by China's National Medical Products Administration (NMPA) for use with lenalidomide and dexamethasone in adults with multiple myeloma who have received at least one prior line of therapy. Anti-CD38 mechanism context: CD38 is a transmembrane glycoprotein highly expressed on multiple myeloma plasma cells and less on normal cells, making it a validated target for monoclonal antibody therapy. Felzartamab represents an alternative anti-CD38 mechanism to Sanofi's SARCLISA (isatuximab) and Johnson & Johnson's DARZALEX (daratumumab), the two commercial anti-CD38 monoclonal antibodies that have anchored the anti-CD38 multiple myeloma commercial segment since first approvals in 2015 (daratumumab) and 2020 (isatuximab). Felzartamab's specific differentiation lies in a distinct epitope-binding domain on CD38 that may translate to different infusion-reaction profiles and combination-therapy potential. The China NMPA approval marks TJ Biopharma's first regional commercial launch for felzartamab and extends the Biogen-China partnership approach for both ex-China drug development and in-China commercial positioning. Beyond multiple myeloma, felzartamab is being studied for anti-neutrophil cytoplasmic antibody-associated vasculitis (ANCA vasculitis), IgA nephropathy, and antibody-mediated kidney transplant rejection in ex-China trials that Biogen leads.
Biogen (NASDAQ: BIIB) reported Q2 2026 earnings before market open Wednesday July 29, 2026 with total revenue of $2.74 billion (+3% year-over-year), GAAP diluted EPS of $0.66, and non-GAAP diluted EPS of $3.60, beating Wall Street consensus. Growth-portfolio drugs (LEQEMBI, SKYCLARYS, SYFOVRE, and EMPAVELI) delivered year-over-year growth and, in aggregate, growth-portfolio revenue exceeded $1 billion for the quarter, surpassing Biogen's legacy multiple sclerosis franchise. Two major pipeline milestones anchored the earnings call: the FDA approved LEQEMBI IQLIK (lecanemab-irmb, a subcutaneous autoinjector formulation) for at-home initiation dosing (following the earlier approval of LEQEMBI IQLIK for maintenance dosing), providing patient-friendly dosing throughout the treatment course; and the Apellis acquisition that closed May 14, 2026 contributed $128 million in combined SYFOVRE (pegcetacoplan intravitreal, for geographic atrophy) and EMPAVELI (pegcetacoplan subcutaneous, for paroxysmal nocturnal hemoglobinuria and C3 glomerulopathy) revenue in the partial quarter. Biogen expects approximately 0.85 EPS dilution from the Apellis acquisition in 2026 with accretion in 2027 and estimated run-rate synergies of at least $250 million exiting 2027. 2026 revenue guidance raised to mid-single-digit growth with non-GAAP EPS guidance of $12-13.
Biogen (NASDAQ: BIIB) presented full Phase 2 CELIA study data for diranersen (BIIB080), an investigational tau-targeting antisense oligonucleotide (ASO) delivered intrathecally, at AAIC 2026 in London on Tuesday July 14, 2026 during the Developing Topics in Phase 2 Clinical Trials Session (2:00-3:30 PM BST). The 76-week placebo-controlled study evaluated three doses (60 mg every 24 weeks, 115 mg every 24 weeks, and 115 mg every 12 weeks) and did not meet its primary endpoint of dose response on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) at Week 76. Strong reductions in tau pathology occurred across all studied doses, generally consistent with the Phase 1b study. Prespecified analyses of cognitive endpoints demonstrated slowing of clinical decline across all doses, with the effect particularly pronounced at the lowest 60 mg q24w dose. Biogen framed the results as the first randomized Phase 2 evidence of a tau-directed therapy showing both biomarker impact and cognitive benefit, and plans to advance diranersen to registrational Phase 3 development.
Eisai and Biogen announced Tuesday July 14, 2026 that data from the real-world Lecanemab in Early Alzheimer's Disease (LEADER) Study, presented at AAIC 2026 in London during the Developing Topics Session '#3-33-DEV-A: Lecanemab Three Years Post-Approval: A Comprehensive Multicenter, Real-World, Retrospective Study (LEADER) in Diverse US Clinical Settings,' documented durable clinical outcomes with LEQEMBI in early Alzheimer's disease. The analysis included 432 early Alzheimer's disease patients from diverse US clinical settings who had received at least seven LEQEMBI infusions as of May 2026. Over an average of 17 months of treatment, 75.9% of patients remained clinically stable and 6.6% improved (moving from mild Alzheimer's disease dementia to mild cognitive impairment due to Alzheimer's disease). 87% of patients chose to remain on LEQEMBI treatment. Results were consistent across sex, race, ethnicity, and APOE genotype, supporting long-term benefits of continuous treatment outside of a controlled clinical trial setting.
Eisai and Biogen announced Sunday July 12, 2026 that new clinical data presented at AAIC 2026 in London support that the LEQEMBI (lecanemab) subcutaneous autoinjector (SC-AI) formulation offers efficacy and safety comparable to intravenous (IV) administration in people with early Alzheimer's disease. Data were featured during the Developing Topics Session titled 'Lecanemab Subcutaneous Formulation in Early Alzheimer's Disease: Emerging Clinical Evidence and Practical Use Considerations,' covering the SC formulation, long-term use across diverse patient groups, maintenance dosing, and at-home administration. The findings support a fully subcutaneous treatment pathway from initiation through maintenance treatment, offering greater convenience and flexibility for patients and care partners. The FDA approved Eisai's Biologics License Application (BLA) for subcutaneous maintenance dosing with LEQEMBI IQLIK in August 2025; the SC autoinjector data at AAIC 2026 extends that framework to initial treatment and long-term dosing. Lecanemab is a humanized IgG1 monoclonal antibody selective for amyloid protofibrils; the July 12 dataset is peptide-adjacent to the broader biologic-CNS delivery coverage.
Biogen (NASDAQ: BIIB) will present Phase 2 CELIA study data for diranersen (BIIB080), an investigational tau-targeting antisense oligonucleotide (ASO), at AAIC 2026 in London during the Developing Topics in Phase 2 Clinical Trials session on Tuesday July 14, 2:00–3:30 PM BST. The 18-month CELIA study evaluated diranersen in patients with early Alzheimer's disease and is the first study to show reduction in tau pathology and cognitive benefit for a tau-targeted therapy. Biogen will present clinical, biomarker, and safety data that build on the May 2026 topline announcement and further characterize the molecule as the program advances toward Phase 3 development. Diranersen targets MAPT RNA to reduce tau production at its source, a differentiated approach to addressing abnormal tau both inside and outside neurons. The CELIA readout is a peptide-adjacent nucleic-acid biologic milestone that shifts the tau treatment conversation from 'reducing pathology' to 'reducing pathology and moving cognition.'
Biogen (Nasdaq: BIIB) completed its $5.6B acquisition of Apellis Pharmaceuticals on May 14, 2026 after the May 13 tender offer closed at 82.4% of outstanding common stock at $41 per share in cash plus contingent value rights (up to $4 per share tied to SYFOVRE global net sales milestones). The transaction brings two commercialized peptide-based products into Biogen's portfolio: pegcetacoplan (EMPAVELI), a pegylated cyclic 13-amino-acid peptide complement C3 inhibitor approved for paroxysmal nocturnal hemoglobinuria (PNH) and C3 glomerulopathy / immune complex-membranoproliferative glomerulonephritis; and SYFOVRE, the intravitreal pegcetacoplan formulation for geographic atrophy secondary to age-related macular degeneration. Combined 2025 net product revenue was $689M. Biogen expects the deal to be Non-GAAP EPS accretive in 2027 and to materially increase Biogen's compound annual growth rate through end of decade. The deal restores a meaningful peptide-modality presence to Biogen's portfolio.