Two studies from Germany show that novel immunotherapies can specifically switch off disease-causing immune cells in inflammatory rheumatic diseases that are difficult to treat. In the medium term, the approaches could open up new treatment options for patients for whom previous therapies are not sufficiently effective.

Around 1.8 million people in Germany are affected by inflammatory rheumatic diseases, including chronic joint diseases as well as rare autoimmune diseases such as systemic lupus erythematosus, systemic sclerosis or inflammatory muscle diseases. Despite progress, these diseases remain incurable and cannot be successfully treated in all those affected. Previous therapies often dampen the immune system broadly and for years, which weakens the body’s own defenses.

The new approaches aim to reprogram the immune system through a targeted one-time elimination of disease-causing cells. An international team led by researchers from the University Hospital Düsseldorf investigated bi-specific antibody constructs, so-called T cell engagers. These molecules specifically connect the body’s own T cells with disease-relevant immune cells and trigger their destruction. The approach showed that disease-causing cell populations can be eliminated in severe systemic diseases such as systemic sclerosis and antisynthetase syndrome.

The CASTLE study at the University Hospital Erlangen tested the use of CAR-T cells directed against CD19 in severe autoimmune diseases. In this process, the patient’s own immune cells are genetically modified in the laboratory so that they specifically recognize and destroy antibody-producing B cells. The therapy has been used in therapy-resistant courses of systemic lupus erythematosus, systemic sclerosis and idiopathic inflammatory myositis. The results indicate sustained clinical improvements.

The German Society for Rheumatology and Clinical Immunology (DGRh) sees both studies published in “Nature Medicine” as an important step forward. They underline the international visibility and innovative strength of German rheumatology. However, further studies are needed to evaluate the efficacy and long-term safety of the therapies.

Original Papers:

Düsing C. et al.: Bispecific T cell engagers for treatment-refractory autoimmune connective tissue diseases. Nature Medicine (2026). https://pubmed.ncbi.nlm.nih.gov/41714747/ “Bispecific T cell engagers for treatment-refractory autoimmune connective tissue diseases – PubMed”

Müller F. et al.: CD19 CAR-T cells for treatment-refractory autoimmune diseases: the phase 1/2 CASTLE basket trial. Nature Medicine (2026). https://pubmed.ncbi.nlm.nih.gov/41501497/ “CD19 CAR-T cells for treatment-refractory autoimmune diseases: the phase 1/2 CASTLE basket trial – PubMed”

Editor: X-Press Journalistenbüro GbR

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