Autoimmunity is when your immune system attacks your own body. Some examples of autoimmune diseases include Rheumatoid Arthritis, Inflammatory Bowel Disease (IBD, not to be confused with IBS!) Multiple Sclerosis and Lupus. There is no cure, and the only way to manage it is by trying to slow the symptoms and disease. In an exciting plot twist, a cancer drug has been causing autoimmune patients to go into long-term remission, meaning no symptoms, no signs of disease. The cell and gene therapy biotech space is now ablaze in excitement over the headlines.
Firstly, what’s this cancer drug??
Immunotherapy is a type of cancer treatment that helps the immune system fight cancer. One powerful example is CAR T cell therapy, which is already used to treat several blood cancers. Here’s how it works: clinicians take some of a person’s own immune cells (called T cells) and send them to a lab. There, scientists “reprogram” them with special instructions. You can think of this like giving them a GPS (or, a final destination it needs to reach) so they can find and attack the cancer cells. That GPS is called a CAR, short for Chimeric Antigen Receptor. Once these engineered T cells are made and multiplied, they’re put back into the patient. Now the body has an army of T cells trained to seek out and destroy the cancer. This approach has been a major success for blood cancers like leukemia and lymphoma, with seven FDA-approved therapies so far. Researchers are now testing it for solid tumors, such as pancreatic, brain, and colorectal cancers. These cancers are trickier to treat, but progress is being made
So how is this relevant to autoimmunity?
How the FDA-approved CAR T cell therapy works is by destroying all the patient’s B cells. Why B cells? In blood cancers like leukemia and B cell lymphomas, it’s the B cells that turn cancerous. But, B cells are also troublemakers in autoimmune diseases, as they go rogue and start to make antibodies to target your own organs. Antibodies act like a tag, sticking all over the organ as it makes the mistake of thinking the organ is foreign, which ends up attracting immune cells to come and attack it. Be it the gut for IBD, your joints for Rheumatoid Arthritis, or the layer that covers your nerves for Multiple Sclerosis. So, what if we destroy all the B cells in an autoimmune patient, would their autoimmunity go away? Some of you may now be thinking, “hold up, I’m already on a drug that stops my B cells, how is this different?” Yes, some people may be prescribed a drug that does the job of getting rid of your B cells, but maybe using this CAR T cell to hunt down all your B cells will do a better job?
The landmark trial
In 2021, scientists in Germany tried exactly that. They took the CAR T cell therapy and injected it into a 20-year-old woman with lupus. Remarkably, she went into remission. Then, they tried this with 5 lupus patients in 2022, guess what? They all went into remission too. Last year, a clinical trial enrolled people with 3 types of autoimmune diseases: lupus, idiopathic inflammatory myositis, and systemic sclerosis. They reported results after 2 years of following them up. Guess what? The patients stopped their medication, all lupus patients went into remission and the sclerosis and myositis patients reported massive improvements. This kicked off a revolution in the cell and gene therapy space.
Now, there are dozens of clinical trials, with one recent paper counting over 100, testing CAR T cell therapy for autoimmune diseases like multiple sclerosis, rheumatoid arthritis, myasthenia gravis, and ulcerative colitis, among others. As the clinical trial results are being released in real time, patients seem to be either in remission, off their medication, or have massive improvements in their symptoms. With that, biotech and pharma giants are literally pivoting from cancer to autoimmunity, as this strategy may finally give us hope as the next big breakthrough to stop autoimmunity in its tracks.
However, there are some remaining questions. Firstly, although B cells are troublemakers in autoimmunity, they are not the only problem. For some of you who are on various drugs for autoimmunity, you’d know that there are other components of your immune system that may be causing the issue. This is why scientists remain hesitant to use the word “cured”. The immune system is extremely complicated, and at some point, due to a mixture of genetics and environmental triggers, your immune system flipped, starting to mistake one of your organs as a villain. Will killing off all your B cells be enough? Let’s wait and see!
