Søren Hough

Normally, our immune system is our primary defence against germs. It works well; we breathe in over 100 million viruses and consume over a billion bacteria every day and they rarely make us sick. But what happens when that same system starts attacking us? 

 

That’s the phenomenon underlying autoimmune diseases like lupus: overactive immune cells attacking the host’s body. This can cause rashes, joint pain, and tiredness in lupus patients. Lupus is particularly prevalent Black and Asian communities and, like many autoimmune diseases, is more common among women. It also has no cure.

 

Scientists have begun to explore whether they can treat autoimmune diseases using a cutting-edge strategy called CAR T. CAR T therapy usually involves an injection of cells engineered to attack the patient’s troublemaking tissues in hopes of sparking a “reset” of their immune system. CAR T has proven to be highly effective in treating multiple forms of cancer, opening the door for treating diseases like lupus.

 

But there’s a catch: making CAR T cells is difficult. Manufacturing is expensive and requires extensive regulatory oversight. Not only that, the process of preparing patients to receive a cell transplantation can be harsh, requiring arduous chemotherapy regimens. All of this reduces access and affordability for patients.

 

Some researchers have begun to explore a way to make the cells inside the patients themselves. The idea — called in vivo CAR T therapy — sidesteps manufacturing and transplantation hurdles entirely.

 

This September, Chinese biotech company MagicRNA published results from their clinical trial in The New England Journal of Medicine. The international research team presented data suggesting in vivo CAR T treatment of lupus may bear fruit. According to their results, the five patients in the trial experienced no serious adverse events and avoided known neurotoxicity of traditional CAR T therapy. 

 

The study was limited in size and duration. Nevertheless, the authors are cautiously optimistic that the treatment could eventually provide “long-term drug-free remission.”

 

This contrasts starkly with the status quo for individuals living with lupus. “Once diagnosed, patients require lifelong medication to control the disease,” study author and MagicRNA CSO Ze Xiu Xiao told me. “Long-term use of [available drugs like] glucocorticoids, immunosuppressants, and hydroxychloroquine leads to various side effects, yet the disease may still progress or relapse.”  

 

She stressed that these patients “urgently” need “a treatment that can fundamentally cure the disease and achieve a sustained remission.”

 

CAR T cells are ideal for battling lupus because they are “living drugs,” in Xiao’s idiom. That means that unlike competing therapies, they systematically seek out and hunt down the haywire immune cells causing the condition. She noted that it is important to remove all “residual” offending cells in order for the immune reset to work.

 

Xiao’s team further innovated by avoiding using viruses in their CAR T therapy, eschewing potential safety hazards associated with viral in vivo medicines. Instead, they used the same basic principles underlying the COVID-19 messenger RNA (mRNA) vaccine to convert the patient’s cells into miniature drug factories. Xiao emphasized that this approach yields therapeutic effects faster than a virus and provides “superior safety” — all while achieving comparable levels of efficacy.

 

Xiao is optimistic that her team’s CAR T drug will be able to reach most individuals with lupus: “Unlike [other] CAR T-cell therapies, its low production cost ensures broad affordability and strong accessibility for the vast majority of patients.”

This clinical study is only a proof-of-concept. But given these early successes, the prospect of turning our bodies into cutting-edge drug manufacturing plants could have enormous implications not only for lupus, but a range of autoimmune diseases.

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This article was written on spec for a magazine like The Economist. The header image is courtesy of NIAID, CC BY 2.0.