CAR-T and cellular therapies carry real infection risks — but we're still flying blind

CAR-T cell therapies and bispecific T-cell engagers are transforming treatment for autoimmune diseases — but their infectious and immunologic risks are still poorly understood. A systematic review presented at ACR Convergence analyzed 25 studies across patients with 15 different autoimmune conditions, finding that nearly half experienced infectious complications and nearly two-thirds developed hypogammaglobulinemia (low antibody levels), a growing concern especially with BCMA-directed therapies.

Researcher Cassandra Calabrese, DO, of the Cleveland Clinic, noted that while serious infections do occur, inconsistent and incomplete reporting across studies makes it nearly impossible to draw meaningful comparisons — or to build reliable risk profiles for patients. The rapid expansion of these therapies in autoimmunity, she warned, has outpaced the field's ability to track their dangers.

By the Numbers:

• 43% of 124 evaluable patients experienced infectious complications
• 65% of 123 patients developed hypogammaglobulinemia
• 14% serious infection rate among 113 evaluable patients
• 67% infection rate with T-cell engagers — the highest across therapy types
• 0 fatalities reported among 65 evaluable patients

Why it matters: As cellular therapies move beyond oncology into autoimmune disease treatment, clinicians need reliable safety data to counsel patients and prevent complications. Without standardized reporting, that guidance remains out of reach.