Current therapies for rheumatoid arthritis rely on sustained immunosuppression rather than restoration of immune tolerance, with off-drug remission remaining rare.

Chimeric antigen receptor (CAR) T‑cell therapy, long established in hematologic malignancies, is now emerging as a transformative approach in systemic lupus erythematosus (SLE), a disease historically managed with chronic immunosuppression.

The year 2025 presented numerous advances in rheumatology and related inflammatory and autoimmune disorders ranging from several new groundbreaking FDA approvals/indications, drug developments, game-changing guidelines and practices that will impact patient care for rheumatic diseases.

CAR T cell therapy took the centre stage in 2022 where data pertaining to a successful case series of 5 patients with refractory SLE were published by Prof Schett’s group. Since then, this area of therapeutic has expanded exponentially. Our growing enthusiasm was slightly dampened though when the FDA required all six approved CAR T-cell therapies in oncology to include a black box warning regarding the risk of second primary malignancies in January 2024. At ACR25, Prof Schett’s group described a new form of toxicity in patients with autoimmune disease receiving CAR T-cell therapy, most likely due to the cleansing of immune cells from the affected organs.

Following the landmark case series by the Erlangen group, multiple cellular therapies have entered the race—each with unique targets, constructs, and mechanisms. Yet, a fundamental question remains: How deep is the B-cell depletion? In clinical practice, peripheral blood counts often serve as our surrogate for depletion. But these may only tell part of the story.

Drs. Jack Cush & Arthur Kavanaugh, two of rheumatology’s most trusted voices, provide a breakdown of the latest breakthroughs and hottest topics in rheumatology from the 2025 ACR Convergence meeting in Chicago.

Here's the last installment of our "ACR Best" abstracts as chosen by the RheumNow faculty.  Most of these were from the final, day 4, but a few were noteworthy holdovers from day 3. Enjoy!