Allogeneic NK cell therapy for refractory RA shows 71% ACR50 in small Phase 2a cohort; Phase 3 RCT will prove or disprove whether outpatient B-cell reset scales

Artiva Biotherapeutics is a clinical-stage company developing an allogeneic cell therapy for rheumatoid arthritis that has not yet been approved.

AlloNK plus rituximab achieved 71% ACR50 at six months in seven refractory RA patients with complete B-cell depletion, no CRS, and outpatient administration, prompting RMAT designation and FDA alignment on a single Phase 3 RCT. The thesis works if Phase 3 in roughly 150 patients replicates that response rate against rituximab alone. The core risk is that seven-patient Phase 2a data, however clean, leaves effect-size uncertainty that a randomized 150-patient trial could dissolve.