Living with an autoimmune disease often means navigating a lifelong, complex condition. A recent study estimates that autoimmune diseases affect 400 to 600 million people worldwide, with the burden continuing to grow.
The treatment paradigm for these millions often centers on symptom management, mainly through medications that broadly suppress the immune system. Yet even then, sustained remission isn't always achievable.
As a researcher and physician, I am encouraged that the field is experiencing a shift toward precision immunology, driven by breakthroughs in our understanding that dysregulated B cells and plasma cells play central roles in driving autoimmune pathophysiology. This insight has opened the door to what we call ‘immune reset’: eliminating disease-driving immune cells so the immune system can rebuild and restore tolerance. Instead of long-term suppression, the goal is durable remission.
T Cell Engagers: Designing the Path to Immune Reset
In the U.S. alone, autoimmune diseases impose over $100 billion in direct annual costs on our healthcare system, underscoring why transformative approaches are urgently needed. Emerging scientific data suggests that T cell engagers represent a promising class of biologics that may enable a long-lasting disease-modifying response through an ‘immune reset’.
T cell engagers act like a molecular matchmaker, bringing T cells into direct contact with autoreactive B cells so they can be efficiently eliminated. T cell engagers build on lessons from earlier approaches such as anti-CD20 antibodies but aim to go further by more deeply and broadly eliminating B cells and antibody-producing plasma cells. While CAR T therapies established what’s possible with a logistically complex modality, T cell engagers may offer a more scalable, accessible way to redirect T cells to ‘reset’ the immune system in autoimmune diseases. This is fundamentally different from current approaches: rather than simply easing symptoms, T cell engagers have the potential to address the root cause of disease.
From a clinical perspective, T cell engagers could offer patients a more manageable treatment experience. Subcutaneous administration offers dosing and retreatment options that may reduce patient time in healthcare settings and allow greater flexibility in care. Equally important, T cell engagers can be manufactured at scale and provided in an off-the-shelf format, which could broaden patient accessibility while reducing the burden on providers and healthcare systems.
Targeting Multiple Pathways for Broader Impact
B cells and plasma cells from across the maturation continuum may play a different role in the pathophysiology of specific autoimmune diseases and may therefore require treatments that target different populations of cells to most effectively address the abnormal immune system response. Multiple promising targets have been identified, each potentially central to modifying different autoimmune diseases. This diversity of targets represents a significant opportunity for the field.
At Cullinan Therapeutics, our investigation of two distinct T cell engager programs reflects an intentional approach to this opportunity. Each program targets B cells at different stages of the cellular maturation process, allowing us to address different diseases and potentially reach more people across a broader range of autoimmune conditions than either molecule could address alone.
CD19, a protein expressed throughout the B cell lineage, provides an opportunity for broad B cell depletion. Our investigational CD19-directed bispecific T cell engager, CLN-978, is designed to deeply deplete autoreactive B cells, and is currently being studied in systemic lupus erythematosus, rheumatoid arthritis, and Sjögren’s disease in active clinical trials across multiple countries.
B cell maturation antigen (BCMA) is highly expressed on long-lived plasma cells that can drive persistent autoimmune activity. Our investigational BCMA-targeted bispecific T cell engager, velinotamig, licensed from Genrix Bio, builds on early efficacy data in relapsed/refractory multiple myeloma and is planned for study in autoimmune diseases driven by self-reactive long-lived plasma cells.
Progressing these separate programs exemplifies how the industry can address the full spectrum of autoimmune pathology, developing treatments that better match the complexity of autoimmune disease biology.
Patient Needs Shaping the Next Wave of Innovation
It’s clear that the millions of people living with autoimmune diseases need more than incremental progress. I believe T cell engagers represent the next wave of innovation to deliver on that need. The possibility of sustained remission without long-term immunosuppression represents a paradigm shift that could dramatically improve quality of life while reducing long-term system burden.
But progress must extend beyond clinical outcomes. My colleagues at Cullinan Therapeutics remain focused on how patients experience their treatment, from early development through clinical trials and beyond. From convenience to accessibility, our goal is to create a future where patients spend less time managing their conditions and more time on what matters most.
If successful, these advances won’t just mean new medicines — they could redefine autoimmune care by providing long-lasting remission and giving patients the opportunity to live without the constant burden of disease.
