Sonoma Biotherapeutics has presented Phase I data for CAR-T therapy SBT-77-7101, showing 67% of refractory rheumatoid arthritis (RA) patients achieved 50% or greater reduction in swollen and tender joint counts at 4 weeks, with DAS28-CRP improvement exceeding 2 points. The autologous cell therapy targeting citrullinated proteins demonstrated a favourable safety profile across two dose cohorts with no dose-limiting toxicities, cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome events reported. The higher dose cohort showed more rapid and sustained joint count reduction, with clinical benefit maintained through 18 weeks follow-up.

The company, founded by Nobel Prize winner Fred Ramsdell, develops engineered regulatory T-cells for restoring immune tolerance in autoimmune diseases with USD 360 million in funding and a partnership with Regeneron generating USD 120 million in upfront and milestone payments. Biopsy samples revealed reduced inflammation scores, supporting the mechanism of action of synovial tissue modulation. Sonoma CEO Jeff Bluestone highlighted the durable response and clean safety profile supporting continued dose escalation and expansion in RA, with potential applications across multiple autoimmune conditions including hidradenitis suppurativa.