Lupus is a lifelong disease that has no cure. It affects an estimated 1.5 million people in the United States and 5 million people worldwide, many of them young women, according to the Lupus Foundation of America. Most patients are treated with steroids to tame the inflammation. Immunosuppressant drugs are also used, but these make the body more vulnerable to infection and often have unpleasant side effects. New antibody drugs, which aim to protect the body from attacking itself, are able to help some patients but not all.
The new study suggests a possible treatment for lupus patients who don’t benefit from currently available drugs. “This impressive study adds to the growing body of evidence that CAR-T therapy may be a therapeutic option for diseases beyond cancer, including autoimmune disorders such as lupus,” Jonathan Epstein, executive vice dean and chief scientific officer of the University of Pennsylvania’s Perelman School of Medicine, wrote to WIRED via email.
In cancer patients treated with CAR-T therapy, complete remission rates are as high as 68 to 93 percent, but relapse remains common and occurs in 40 to 50 percent of patients. Cancer patients treated with CAR-T therapy can also have a severe inflammatory reaction called cytokine release syndrome. In the lupus study, patients experienced only mild side effects, including fever.
“The difference between cancer and autoimmunity is that in cancer, there are usually more cells involved,” says Georg Schett, vice president of research at the University of Erlangen-Nuremberg in Germany, who was part of the study team. When engineered T cells go after so many tumor cells at once, it can over-activate the immune system and release a potentially life-threatening cytokine storm. “Whereas in autoimmunity, the number of B cells is much lower, and therefore it seems that the safety profile of CAR-T cell therapy and autoimmunity is much better than in cancer,” he says.
Schett’s team is planning a larger study called a basket trial, in which patients with different types of autoimmune conditions, such as rheumatoid arthritis and scleroderma, will be treated with CAR-T therapy. He says longer follow-up in larger clinical trials will be needed to determine whether the therapy is really a cure.
While these early results are promising, the complexity and cost of CAR-T may limit its use for the foreseeable future. Currently, CAR-T therapies for cancer cost around $400,000 for a one-time infusion. Since they’re tailored to each patient, they’re complicated to make and require special manufacturing capabilities. Because of these factors, Nguyen says she sees this therapy initially being used as a last resort for patients with severe lupus who don’t respond to other drugs. “My first thought when I saw the work was, ‘Wow, this is going to be really expensive,’” she says.