A Phase 1 Study of FT819 in B-cell Mediated Autoimmune Disease

Key Inclusion Criteria:

• Age: 12 to 70 years old.

• Diagnosis: Must have active B-cell mediated autoimmune disease (SLE, AAV, IIM, orSSc) confirmed by standard criteria.

• Disease Severity: Moderate to severe, requiring at least two prior treatments thatwere ineffective.

• Health Status: Adequate organ function to tolerate treatment.

• Consent: Able to provide informed consent or assent/obtain parental consent andcomply with study procedures.

Key Exclusion Criteria:

• Pregnancy/Breastfeeding: Women must not be pregnant or nursing.

• Severe Organ Dysfunction: Significant heart, lung, liver, or kidney impairment.

• Active Infections: No recent or ongoing serious infections.

• Recent Cancer or Prior Cell Therapy: No active/recent malignancies, prior CAR T-celltherapy, or organ transplant.

• Allergies: No known allergies to study treatments.

• Weight Restriction: Must weigh at least 50 kg (110 lbs).