CAR-T Cell Therapy Shows Promise in Severe Lupus: Immune Reset, Fertility Preservation

Early results from clinical trials suggest that CAR-T cell therapy could offer a new treatment approach for people with severe, treatment-resistant lupus, with emerging evidence also indicating that the therapy can preserve fertility in female patients.

Findings from the ongoing Phase I CARLYSLE study, presented at the EULAR European Congress of Rheumatology, evaluated obecabtagene autoleucel (obe-cel) in patients with severe refractory systemic lupus erythematosus (SLE). The study, led by UCL and UCLH, enrolled patients aged 12 to 65 with active, severe disease who had not responded to multiple standard treatments. Participants received a single infusion of obe-cel following lymphodepletion, at one of two dose levels.

As of November 2025, nine adult patients had been treated. All had highly active disease at baseline, and most were affected by lupus nephritis. In the lower-dose group, five out of six patients achieved remission according to standard lupus criteria, with responses emerging within a few months of treatment. Patients also experienced rapid improvements in disease activity scores, as well as reductions in key disease markers such as anti-double-stranded DNA antibodies and increases in complement levels. For patients with kidney involvement, several achieved complete or partial renal responses, with reductions in proteinuria and stabilisation or improvement of kidney function over time.

Researchers observed no cases of immune effector cell-associated neurotoxicity syndrome (ICANS) and no moderate or severe cytokine release syndrome (CRS). There was one dose-limiting toxicity involving liver injury, which fully resolved. Other side effects, including neutropenia and infections, were consistent with expectations for CAR T-cell therapy and were considered manageable.

Following infusion, patients showed strong expansion of CAR T cells and deep depletion of B cells. Over time, B cells began to return, typically between three and six months, but were predominantly early-stage (transitional and naïve) cells rather than the more mature populations associated with autoimmune activity, suggesting the therapy may be enabling an "immune reset."

In a separate case reported in Arthritis & Rheumatology, a 24-year-old woman with refractory lupus nephritis achieved two successful pregnancies following dual-target BCMA/CD19-directed CAR-T cell therapy, with no evidence of CAR-T cell transmission to either infant. The patient was diagnosed with SLE at age 20 and developed class IV lupus nephritis. After achieving sustained molecular remission, the patient became pregnant spontaneously at 6 months and 21 months post infusion. Throughout both pregnancies, lupus activity remained minimal without flares or any new disease activity. Both vaginal deliveries of healthy neonates were uncomplicated and to term.

Analysis of the patient's blood, breast milk, and placenta, as well as the infants' blood at birth and during follow-up, were all negative for CAR-T cell DNA. Both infants showed normal growth, neurodevelopment, and immune function. The researchers noted that CAR-T cell therapy might even mitigate typical obstetric complications of SLE such as placental inflammation, preeclampsia, and neonatal lupus, through its effect on immune quiescence. They called for expanded research and evidence-based fertility guidelines for patients considering pregnancy after CAR-T cell therapy.