A cancer therapy put severe rheumatoid arthritis into remission

 Immunotherapies such as CAR T-cell therapy were originally developed mainly to fight cancer. But scientists are now investigating whether these personalized treatments, made from a patient's own immune cells, could also help treat or even potentially cure autoimmune diseases.

Researchers at Charité - Universitätsmedizin Berlin have now tested CAR T-cell therapy in six people with particularly severe rheumatoid arthritis. The world's first clinical trial of its kind, reported in Nature Medicine, produced encouraging early results. Disease activity fell substantially in every participant, and by the end of the observation period, three patients no longer needed rheumatoid arthritis medication.

Why Rheumatoid Arthritis Can Be So Difficult To Treat

Rheumatoid arthritis is a chronic autoimmune disease in which the immune system mistakenly attacks the joints. Repeated inflammation causes swelling and can eventually damage the joints.

Existing medications are often effective at controlling inflammation, but they generally do not cure the disease. As a result, many patients need lifelong treatment with anti-inflammatory drugs and medications that suppress the immune system, which can also cause side effects.

For some people, even newer therapies do not work well enough. Doctors describe these cases as treatment-refractory rheumatoid arthritis. Patients can continue to experience pain, limited mobility, and major reductions in quality of life despite trying multiple treatments.

"One reason could be disease-driving B cells - memory cells of the adaptive immune system that may survive in the lymph nodes, bone marrow or joint tissue after an infection, where they produce harmful antibodies directed against the body's own tissues and repeatedly reignite the inflammation," explains Prof. David Simon, who designed the trial for this patient group together with Prof. Gerhard Krönke at Charité's Department of Rheumatology and Clinical Immunology.

The researchers are testing whether CAR T cells can seek out these disease-driving B cells even when they are buried deep within body tissues. Their goal is to eliminate as much of the abnormal B-cell memory as possible and effectively give the B-cell system a new start.

Using Cancer Immunotherapy To Reset the Immune System

CAR T cells were first developed as a cancer treatment, but their potential uses are expanding. In cancer therapy, a patient's immune cells are modified so they can recognize and destroy tumor cells. For autoimmune diseases, scientists instead want to direct those engineered cells toward immune cells that help sustain the disease.

"The identifying marker on many B cells, both abnormal B cells in cancers of the blood or lymphatic system and disease-driving B cells in rheumatoid arthritis, is the surface molecule CD19. You could think of it as a kind of 'name tag'," explains David Simon. "To enable CAR T cells to detect and eliminate the disease-causing cells, we equip patients' own immune cells with a receptor that acts like a search sensor for CD19."

To produce this form of CD19 CAR T-cell therapy, doctors first collect T cells from the patient's blood. T cells are immune cells that normally help recognize and destroy infected or abnormal cells.

Scientists then genetically modify those T cells in the laboratory. The cells receive a chimeric, or artificial, antigen receptor known as a CAR, which is designed to bind specifically to CD19.

Before receiving the modified cells, patients undergo a short course of preparatory chemotherapy. This temporarily lowers the number of certain immune cells, creating room for the CAR T cells to multiply and function effectively.

The engineered cells are then returned to the patient in a single infusion. Once inside the body, they search for cells carrying CD19 and attack them. This temporarily removes all CD19-positive B cells, including long-lived disease-driving cells in the joints that can otherwise be difficult to reach. By clearing out those cells, the treatment may allow the immune system to reset.

First Trial in Severe Rheumatoid Arthritis

For the first clinical trial evaluating both the safety and effectiveness of CD19 CAR T-cell therapy in rheumatoid arthritis, the Charité team initially enrolled six patients with especially severe disease.

The group included three women and three men between the ages of 31 and 69. During the previous decade, they had received as many as eight targeted or biologic therapies, but none had controlled their disease adequately.

Researchers wanted to learn whether CAR T cells could reach the disease-driving B cells inside the joints and whether the approach could do so safely.

The first phase of the COMPARE trial produced results the team considers highly encouraging.

"Disease activity decreased markedly in all six patients. During follow-up of up to one year, three patients were in sustained remission without any medication for rheumatoid arthritis," reports Gerhard Krönke, who leads the joint Clinical Rheumatology research group at Charité and the German Rheumatology Research Center (DRFZ), a Leibniz Institute. "This is particularly remarkable given that none of the established treatments had previously been able to relieve their symptoms adequately."

CAR T Cells Reached Hidden Disease Reservoirs

The treatment appeared to do more than temporarily reduce inflammation in the joints. Researchers found that the modified immune cells also reached and eliminated disease-promoting B cells in deeper locations, including the bone marrow, lymph nodes, and joint tissue.

During regular follow-up visits over the following 12 months, levels of the autoantibodies associated with rheumatoid arthritis dropped sharply.

David Simon adds: "When the B-cell system later recovered, predominantly naïve B cells that had not yet been shaped by the disease returned. In contrast, the B cells directed against the body's own tissues that had been present before treatment were no longer detectable in almost all patients, an indication that the treatment may indeed be able to reset the pathological immune memory."

Importantly, antibodies generated by earlier vaccinations, including those against chickenpox and tetanus, could still be detected. That suggests protective antibody memory was largely preserved even though the therapy caused a profound temporary depletion of B cells.

Researchers still need to determine whether the therapy has any longer-term effects on the immune system.

Promising Results, but the Therapy Remains Experimental

The trial suggests that a single CAR T-cell treatment can, in some patients, produce a sustained period without symptoms or rheumatoid arthritis medication. This state of disease inactivity is known as remission.

For carefully selected patients whose rheumatoid arthritis does not respond adequately to available treatments, researchers hope it may eventually be possible to directly reset pathological immune memory and stop the ongoing inflammation rather than continuously suppressing it with medication.

However, CAR T-cell therapy for autoimmune diseases, including rheumatoid arthritis, is still experimental. Researchers do not yet have long-term experience with the treatment.

Responses also differed among the six participants. Some did not achieve a complete response, and one patient's disease returned after an initial period of medication-free remission.

So far, however, the researchers consider the safety findings encouraging.

"After the participants received the CD19 CAR T cells, we observed only a temporary, mild-to-moderate cytokine release syndrome (CRS) in all participants, which was readily manageable. There were no severe neurological complications or other serious adverse events, and infections were rare," explains Dr. Marie Luise Hütter-Krönke, Medical Director of the Hematology Early Clinical Trial Unit at Charité's Department of Hematology, Oncology and Cancer Immunology.

A Larger Comparison Is Next

The second phase of the trial will include ten additional patients. Researchers plan to compare CAR T-cell therapy with an already approved rheumatoid arthritis drug that also targets B cells.

The comparison should help determine whether CAR T cells produce stronger or longer-lasting effects and whether they truly reset immune memory.

If these results are confirmed in this phase and in future larger studies, CAR T-cell therapy could eventually offer another option for people with severe rheumatoid arthritis whose lives are significantly affected by the disease and who currently have no adequate treatment.

About the Study

The first of the two phases of the COMPARE study was designed to assess the safety and effectiveness of CD19 CAR T-cell therapy in treatment-refractory rheumatoid arthritis.

Major contributors included researchers from Charité's Department of Rheumatology and Clinical Immunology and the Department of Hematology, Oncology and Cancer Immunology at Campus Benjamin Franklin, along with scientists from the Cluster of Excellence ImmunoPreCept, the German Rheumatology Research Center (DRFZ), a Leibniz Institute, and the Fraunhofer Institute for Translational Medicine and Pharmacology ITMP.

The study was initiated and designed at Charité and also received support from Kyverna Therapeutics. The immunotherapy company had no role in designing the study, collecting or analyzing the data, or presenting the results.

Journal Reference:

1. Fredrik N. Albach, Marie C. Rehm, Marie Luise Hütter-Krönke, Thanh Hang Le, Julia M. Giezen, Murat Torgutalp, Arne Sattler, Ioanna Minopoulou, Robert Biesen, Edgar Wiebe, Vincent Casteleyn, Thorben Witte, Christian Furth, Jan Zernicke, Melanie Nuesch Germano, Johan Verhagen, Artur Wilhelm, Maria Dzamukova, Klaus Engel, Simon Schallenberg, Aimo Kannt, Nicole Ziegler, Michaela Fehringer, Udo Schneider, Nadine Unterwalder, Mark Beling, Alexander Pfeil, Elpida Phithak, Martin Krusche, Olaf Penack, Tobias Alexander, Werner Stenzel, Manfred Wuhrer, Kamran Movassaghi, Thomas Dörner, Eicke Latz, Thomas Vogl, Antonia Busse, Georg Schett, Hans Ulrich Scherer, Rene E. M. Toes, Arnd Kleyer, Ulrich Keller, Lars Bullinger, David Simon, Gerhard Krönke. CD19 CAR T cell therapy for treatment-refractory seropositive rheumatoid arthritis: a phase 1 trial. Nature Medicine, 2026; DOI: 10.1038/s41591-026-04603-3

Courtesy:

Charité - Universitätsmedizin Berlin. "A cancer therapy put severe rheumatoid arthritis into remission." ScienceDaily. ScienceDaily, 29 August 2026. <www.sciencedaily.com/releases/2026/08/260828082330.htm>. 

 

 

 

 

 

Researchers unveil sustainable spirulina solution to vitamin B12 deficiency

Scientists have found a way to grow Spirulina that produces biologically active vitamin B12 at levels comparable to beef, potentially overcoming one of the biggest nutritional limitations of this widely promoted algae.

The research, published in the scientific journal Discover Food, was led by Dr. Asaf Tzachor, Founder and Academic Director of the Aviram Sustainability and Climate Program at Reichman University, together with researchers from Iceland, Denmark and Austria. Using advanced biotechnology and carefully controlled light conditions, the team produced carbon-neutral, nutrient-rich Spirulina biomass containing active vitamin B12. According to the researchers, this is the first time biologically active vitamin B12 has been reported in Spirulina.

A Global Vitamin B12 Problem

Vitamin B12 is an essential micronutrient involved in several critical processes in the body, including red blood cell formation and normal nervous system function. More than a billion people worldwide are estimated to have low levels of the vitamin.

For many people, meat and dairy products are important dietary sources of B12. The recommended intake cited by the researchers is 2.4 µg/day. However, producing animal-based foods at the scale required to meet global demand also carries environmental costs, which has driven interest in more sustainable alternatives.

Spirulina blue green algae (Arthrospira platensis) has often been promoted as one such option because it is nutrient dense and can be cultivated with a relatively small environmental footprint. But there has been a major obstacle.

Traditional Spirulina contains much of its B12 in the form of pseudo-vitamin B12. Although chemically similar to the vitamin humans need, this form is not bioavailable to people, meaning the body cannot effectively use it. That limitation has prevented conventional Spirulina from serving as a reliable replacement for animal-sourced vitamin B12.

Using Light to Change Spirulina's Nutrition

To address that problem, researchers from Reichman University, University of Natural Resources and Life Sciences, Vienna, Ruppin Academic Center, Danish Technological Institute, and MATIS, Iceland, carried out an exploratory study of a biotechnology platform developed by VAXA Technologies in Iceland.

The team examined the system's engineering design, its inputs (such as energy), and the nutritional composition of the biomass it produced.

A central feature of the technology is photonic management (modified light conditions). By changing the light environment in which Spirulina grows, the researchers were able to encourage production of biologically active vitamin B12.

The cultivated Spirulina also contained other bioactive compounds associated with antioxidant, anti-inflammatory, and immune-boosting properties.

Most notably, the resulting carbon-neutral biomass contained 1.64 µg of active vitamin B12 per 100 grams, compared with 0.7-1.5 μg per 100 grams in beef.

Dr. Asaf Tzachor explains, "the findings demonstrate that photosynthetically controlled Spirulina can produce desirable levels of active vitamin B12, offering a sustainable alternative to traditional animal-source foods."

Could Spirulina Supply Vitamin B12 at Scale?

The researchers also explored what could happen if the system were expanded far beyond its current scale.

In one scenario, reallocating electricity currently used by heavy industry in Iceland could support production of 277,950 tonnes of Spirulina biomass each year. The researchers estimate that this amount would contain about 4555 grams of active vitamin B12 annually.

According to their calculations, that quantity could provide the recommended dietary allowance (RDA) for more than 13.8 million children aged 1-3.

More ambitious production scenarios could potentially supply enough vitamin B12 to meet the RDA for more than 26.5 million children aged 1-3 and more than 50 million children aged 0-6 months.

These figures are projections based on possible scale-up scenarios rather than existing production levels, but they illustrate the nutritional potential the researchers see in the technology.

A More Sustainable Source of an Essential Vitamin

If the approach can be successfully expanded, photosynthetically controlled Spirulina could provide another route for addressing vitamin B12 deficiency while reducing some dependence on meat and dairy production.

The work also highlights how biotechnology can alter the nutritional properties of microorganisms and other rapidly growing food sources. Rather than simply cultivating conventional Spirulina, researchers are changing the conditions under which it grows to encourage production of specific compounds that are useful to humans.

The findings represent a step toward developing more sustainable sources of essential nutrients, although further research and larger-scale production will be needed to determine how the technology could fit into real-world food systems.

Reichman University and the Aviram Foundation established the Aviram Sustainability and Climate Program in response to growing environmental and public health challenges around the world. The program trains students from a range of disciplines to develop strategies for addressing resource scarcity, climate change, and extreme weather events, as well as food, water, and energy crises.

 

Journal Reference:

1. A. Tzachor, S. P. van den Oever, H. K. Mayer, M. Asfur, A. Smidt-Jensen, M. Geirsdóttir, S. Jensen, B. O. Smárason. Photonic management of Spirulina (Arthrospira platensis) in scalable photobioreactors to achieve biologically active unopposed vitamin B12. Discover Food, 2024; 4 (1) DOI: 10.1007/s44187-024-00152-1

Courtesy:

Reichman University. "Researchers unveil sustainable spirulina solution to vitamin B12 deficiency." ScienceDaily. ScienceDaily, 30 August 2026. <www.sciencedaily.com/releases/2026/08/260829035227.htm>.