REACT-01: Reversing Autoimmunity Through Cell Therapy

Inclusion Criteria:

• Male and female subjects aged between 2-30 years old. The first 3 subjects will beaged ≥ 17. The FDA will review safety data to determine if the age can be loweredfirst to ≥ 12 then, following the treatment of 3 further subjects aged 12-17, to ≥ 2

• Serologically active Systemic Lupus Erythematosus that is refractory to treatment

• Able to tolerate apheresis or already has an apheresis product available for use inmanufacturing.

• ≥ 24 weeks post last Rituximab or related B cell depleting therapy

• ≥ 12 weeks post last Belimumab / Anifrolumab therapy

• ≥ 4 weeks post last calcineurin inhibitor treatment

• For subjects receiving non-calcineurin immunosuppressive therapy, on a stable dosefor ≥ 8 weeks before enrollment

• For subjects receiving corticosteroid therapy, on a stable dose for ≥ 2 weeks beforeenrollment

• Adequate organ function

• Adequate laboratory values

• Subjects of childbearing or child-fathering potential must agree to use highlyeffective contraception from consent through 12 months following infusion ofinvestigational product on trial

• Subjects must be willing to remain within 1 hour's drive of Seattle Children'sHospital for 4 weeks following CAR T cell infusion.

• Subject and/or legally authorized representative has signed the informed consentform for this study

Exclusion Criteria:

• History or presence of active CNS lupus or other CNS disease

• Kidney dysfunction requiring renal replacement therapy

• Pregnant or breastfeeding

• Insufficient pulmonary reserve including history of COPD, >10 pack year smokinghistory or SLE lung disease with hypoxia at rest with oxygen saturation ≤92% on roomair

• Unable to tolerate repletion with any formulation of IgG.

• Active or prior malignancy, unless the malignancy was treated and there is noevidence of recurrent disease <5 years from enrollment.

• Prior solid organ transplantation.

• Presence of an active severe infection

• Presence of any condition that, in the opinion of the investigator, would prohibitthe subject from undergoing treatment under this protocol