# In-body engineered immune therapy shows promise for multiple sclerosis Small clinical trial reports improved symptoms in autoimmune disease patients - **Source:** [Nature](https://brifing.si/source/4d850c3b-dd79-4024-bc91-db2571889199) - **Published:** 2026-09-03 - **Original article:** - **On Brifing:** https://brifing.si/s/b3e1f674-2ae9-43a3-90c2-9aebf447eeec ## What is in vivo CAR-T cell therapy? Unlike conventional CAR-T treatments, this approach genetically modifies T cells directly inside the body rather than extracting them first. A carrier virus called lentivirus delivers genetic instructions to produce chimeric antigen receptors (CARs). Published in The New England Journal of Medicine, the study involved 16 participants and offers a faster, more cost-effective solution compared to lab-based cell modification techniques. ## How it works against MS The engineered CAR-T cells target B cells responsible for the immune system's attacks on healthy tissue. Post-treatment monitoring showed increasing CAR-T cell production in participants' blood over time. These cells reduced autoantibody-producing B cells, effectively 'resetting' the immune system. MS patients demonstrated improved motor and cognitive functions with reduced fatigue levels. ## Clinical trial outcomes Over six months of observation, participants showed significant improvement in symptoms like muscle weakness and inflammation. Lead investigator Dai-Shi Tian from Tongji Medical College called the results promising but stressed the need for larger studies to confirm efficacy. Tian noted that permanent immune tolerance hasn't yet been proven, requiring further research. ## Advantages over traditional treatments Current CAR-T therapies are lab-produced and primarily used for blood cancers. This new method shows potential for autoimmune diseases like lupus. Immunologist Bing Du from East China Normal University described developing in vivo CAR-T treatment as a major achievement, with results comparable to ex vivo therapies. ## Technological backbone The study utilized lentivirus designed by China's Shenzhen Genocury Biotech, previously proven effective against blood cancer in 2025. Lentiviral vectors are preferred in gene therapies for their safe and efficient gene delivery. The single-injection approach significantly simplifies treatment administration for patients. ## Reprogramming the immune system Post-treatment analysis revealed patients' newly produced B cells stopped generating autoantibodies, suggesting an immune system 'factory reset.' David Simon from Charité Universitätsmedizin Berlin called this a crucial proof-of-concept for in vivo CAR-T therapy. Immune system retraining could provide fundamental solutions for autoimmune conditions. ## Future research directions Researchers plan larger-scale studies on diverse patient groups. Beyond MS, the method will be tested for other autoimmune disorders affecting muscles, brain, and spinal cord. CAR-T therapy trials for MS have commenced in the US. Widespread adoption could offer new hope for millions with autoimmune diseases. ## Impact on medical community The Nature-published study has generated significant attention in medical circles. Given the cost and complexity of conventional CAR-T production, in-body engineering represents a revolutionary advancement. Experts suggest this could usher in a new era of personalized medicine, adaptable to various diseases including cancer, though long-term effects require further investigation. ## Sources covering this story - https://www.nature.com/articles/d41586-026-02765-1 — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._