Biogen (NASDAQ:BIIB) outlined its immunology and neurology development priorities during a virtual symposium hosted by Piper Sandler, with Dr. Diana Gallagher, head of clinical development for MS, immunology, and Alzheimer’s disease, discussing late-stage lupus programs and earlier-stage pipeline efforts.
Lupus focus: unmet need and long-running investment
Gallagher said Biogen’s prioritization of lupus reflects both the “major unmet need” and the company’s longstanding work in the space. She noted that the BDCA2 program (BIIB059), now called litifilimab, has been in development for more than a decade, and that Biogen has studied CD40 biology—relevant to dapirolizumab—through a collaboration with UCB for roughly two decades.
How Biogen frames differentiation in SLE: undertreatment and steroid-sparing goals
Gallagher said systemic lupus erythematosus (SLE) remains “seriously undertreated,” citing that only about 20% to 30% of U.S. patients receive biologic therapy. She added that many patients still do not reach treatment targets such as lower disease activity and steroid-sparing outcomes, which she linked to the long-term comorbidities associated with chronic steroid use, especially given lupus is often diagnosed in patients in their teens or twenties.
She also emphasized disease variability, saying patients often express the idea that “my lupus is not your lupus,” and argued that a broader set of options is needed because organ involvement and disease activity can change over time in a relapsing-remitting pattern. In that context, she said patients may need to cycle among therapies to balance efficacy and side effects across a lifetime of treatment.
Litifilimab: BDCA2 mechanism and skin and joint manifestations
Discussing litifilimab, Gallagher described it as targeting BDCA2, a receptor expressed on plasmacytoid dendritic cells, which she said are major producers of interferon. By binding BDCA2, she said the therapy aims to interrupt inflammatory cascades that contribute to tissue damage. She added that the approach is intended to influence not only interferons but also downstream pathways including TLR7 and TLR9, affecting other relevant cytokines.
Gallagher characterized the clinical impact as “overall disease control,” pointing to outcomes measured by SRI-4 and to effects on two key manifestations: skin and joints. She said data showed reductions in tender and swollen joints and highlighted improvements in skin disease. She also noted that Biogen received breakthrough designation for cutaneous lupus erythematosus (CLE), describing CLE’s burden in terms of alopecia, scaling, and scarring lesions, often involving the face and other body areas.
Endpoints and timing: SRI-4 vs. BICLA, and CLE vs. SLE readouts
Gallagher explained that Biogen’s late-stage SLE studies use different primary endpoints—SRI-4 for litifilimab and BICLA for dapirolizumab—because those were the proof-of-concept endpoints used earlier and informed powering and trial design. She said both endpoints are established and can support approval, but differ in how response is determined:
- BICLA is based on a BILAG composite requiring partial improvement across all affected organ systems without worsening.
- SRI-4 is based on SLEDAI-2K and requires a 4-point improvement, which she said can be more sensitive to changes in specific organ systems.
Gallagher added that Biogen is measuring both endpoints across the programs (with the alternate endpoint typically included as secondary). On trial duration, she said both the systemic program (TOPAZ) and the CLE program (AMETHYST) will follow patients out to 52 weeks, but AMETHYST Part B has a 24-week primary endpoint using the CLASI skin disease measure. She said the shorter primary timeframe reflects the importance patients place on speed of onset and symptom resolution in dermatologic disease, while still evaluating durability over a year.
Dapirolizumab: steroid tapering and pregnancy-related considerations
Looking back at a successful Phase 3 study of dapirolizumab, Gallagher highlighted the importance of managing steroid use in global lupus trials, noting variation in clinical practice across countries and investigators. She said the program incorporated protocol-defined expectations for steroid tapering, both to support patient wellness and to enable statistical evaluation and potential labeling.
Gallagher said Biogen was encouraged that up to about one-fifth of patients were able to reduce steroids down to 7.5 mg or 5 mg, a range she described as important for reducing long-term side effects.
On safety and pregnancy, she reiterated that lupus disproportionately affects young women who may become pregnant. She said dapirolizumab is “heavily pegylated” and, based on primate data, does not appear to cross the placenta. She also raised the question of whether it avoids transfer into breast milk, framing pregnancy and postpartum use as potentially differentiating if supported by evidence. Gallagher said the company is considering how to examine these questions and is in dialogue with agencies about an appropriate path, while emphasizing the therapy is not yet approved.
Beyond lupus, Gallagher briefly discussed additional pipeline efforts, including a large, controlled Parkinson’s trial of a LRRK2-directed asset (described as a higher-risk, high-reward proof-of-concept effort), a Phase II BTK inhibitor program in relapsing MS with a comparator arm including Vumerity and two doses, and the initiation of a Phase I BTK degrader. She also said Biogen is pursuing a multi-indication strategy for degrader programs, including a BTK degrader and an IRAK4 degrader, and described interest in CD38 biology through felzartamab and a next-generation CD38 asset originating from HI-Bio, with potential relevance across autoimmune diseases beyond kidney indications.
About Biogen (NASDAQ:BIIB)
Biogen Inc is a multinational biotechnology company focused on discovering, developing and delivering therapies for neurological and neurodegenerative diseases. Headquartered in Cambridge, Massachusetts, the company has a longstanding emphasis on neuroscience, with research and commercial activities spanning multiple therapeutic areas including multiple sclerosis, spinal muscular atrophy and Alzheimer’s disease. Biogen was founded in 1978 and has grown into a global biopharmaceutical firm with operations and commercial presence across North America, Europe, Japan and other international markets.
The company’s marketed portfolio has historically included several well-known therapies for multiple sclerosis such as Avonex, Tysabri and Tecfidera, and it has pursued treatments for rare neurological conditions and genetic neuromuscular disorders.
