CAR-T Therapy for Autoimmune Disease in the United States: What's Actually Happening

A technology built to fight blood cancer is now being tested, in trials across the United States, as a way to put severe autoimmune disease into deep remission. This article — part of a series that has already looked at CAR-T for autoimmune disease in Germany, China, the United Kingdom, and Australia — lays out what's genuinely happening in US-based CAR-T autoimmune research right now: which companies and trials are furthest along, what real efficacy and safety data have been reported, and the honest regulatory reality that none of this is an approved treatment yet.

The Basic Idea, Applied to a New Disease Category

CAR (chimeric antigen receptor) T-cell therapy works by removing a patient's own T cells, genetically engineering them to recognize a specific target, and infusing them back into the body to hunt down cells carrying that target. In blood cancer, the target is usually a cancerous cell. In lupus, myositis, and several other autoimmune diseases, researchers are instead targeting CD19, a protein found on B cells — the immune cells responsible for producing the autoantibodies that drive much of the tissue damage in these conditions. The goal is to deplete B cells more thoroughly than existing drugs can, allowing the immune system to effectively reset without the autoreactive population that was driving disease.

Kyverna Therapeutics: From Stiff Person Syndrome to Myasthenia Gravis

Kyverna Therapeutics, a US biotech, is developing KYV-101 — generic name mivocabtagene autoleucel — an autologous anti-CD19 CAR T-cell therapy. According to the company, it has completed a registrational trial in stiff person syndrome, a rare and severely disabling neurological autoimmune disease, and has an ongoing registrational trial in generalized myasthenia gravis, another antibody-driven autoimmune condition. "Registrational" means these trials are designed with an eye toward eventually supporting an FDA approval application, which is a meaningfully further-along stage than early, exploratory safety studies — though it's important to be clear that completing a registrational trial is not the same as having regulatory approval in hand.

Cabaletta Bio: Real Numbers From a Small Lupus Trial

Cabaletta Bio, another US biotech, has reported data from its RESET-SLE trial of rese-cel (resecabtagene autoleucel), also a CD19-directed CAR-T therapy, in patients with systemic lupus erythematosus and lupus nephritis. In results presented at the American College of Rheumatology's 2025 convergence meeting, with a September 2025 data cutoff, nine patients had been treated — five with non-renal lupus and four with lupus nephritis. Among the eight patients with at least three months of follow-up, seven achieved either DORIS remission (a recognized definition of lupus remission) or a complete renal response. All nine patients were off all immunomodulating medications at the data cutoff, and the group showed a meaningful drop in a standard lupus disease-activity score. That's a genuinely encouraging early signal in a disease where sustained, medication-free remission is rare. On safety, six of the nine patients had no cytokine release syndrome at all, and three had only mild (grade 1) CRS — but one patient did experience grade 4 ICANS, a serious neurological toxicity, underscoring that even with encouraging efficacy signals, this remains a therapy with real, sometimes severe risk.

Where US Academic Trials Fit In

Beyond the two companies above, US academic medical centers are also running their own CAR-T autoimmune trials, including a registered pediatric trial based at a major US children's hospital. As this field expands, expect more individual hospital-based and investigator-initiated trials alongside the larger, company-sponsored registrational studies — a pattern similar to how CAR-T first matured in blood cancer before reaching broad approval and adoption.

What's Not True Yet: No Approval, Trial-Only Access

It's worth stating plainly: no CAR-T therapy is FDA-approved for any autoimmune disease in the United States today. Every patient receiving it is doing so inside a formal clinical trial, under research protocols and informed consent — not as a standard or routinely available treatment, and not through any clinic offering it outside of registered trial enrollment. Both of the lead US programs described above have reportedly received certain FDA designations intended to speed development of therapies for serious, unmet medical needs, though exact designations and timelines vary by program and indication, and readers should not assume a specific designation applies to every trial described here. Whether and when either an FDA approval materializes will depend on larger, more mature trial data than what's been reported so far.

Cost Is Also an Open Question

There's no established price yet for an autoimmune CAR-T therapy, since none is approved. For context on what cell therapy pricing has looked like in oncology, where CAR-T products are approved and established: Yescarta, one of the first approved CAR-T cancer therapies, launched with a list price of about $373,000 when the FDA approved it in October 2017. Whether an eventual autoimmune indication would be priced similarly, lower, or differently is simply not known yet, and will be shaped by regulatory, manufacturing, and payer decisions that haven't been made.

Bottom Line

The United States has become one of the most active places in the world for CAR-T autoimmune disease research, with real, company-reported efficacy data now emerging — including a small lupus cohort where most patients reached medication-free remission. That's a genuinely exciting signal in a field that has historically had few ways to durably reset a misfiring immune system. It comes with real, unresolved risk, including a serious ICANS case in a trial of only nine patients, and with a regulatory reality that hasn't changed: this remains investigational, trial-only medicine, not an approved or broadly accessible treatment, and anyone interested in it should be looking at registered clinical trial enrollment through a hospital or academic research program, not a clinic claiming to offer it directly.