Overview

The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, as well as preliminary efficacy of mRNA encoding CD19/CD3 T cell engager (ABO2203) in patients with refractory autoimmune diseases who received inadequate response or relapsed from standard of care (SoC). The trial included dose escalation and dose expansion parts.

Eligibility

Inclusion Criteria:

1. ≥18 years of age at time of informed consent.
2. Diagnosis of autoimmune diseases according to the corresponding disease classification criteria.
3. Inadequate response to SoCs (at least 2 of first-line treatment drugs, including glucocorticoids and immunosuppressants, etc.) or relapsed after the treatment.
4. The results of clinical laboratory tests achieved during the screening period meet relevant criteria defined in the study protocol.
5. Received relevant background SoCs at least 12 weeks prior to screening, and with a stable dose at least 4 weeks prior to the enrollment, it must be planned that the background SoC treatment remains at the stable dose throughout the study period.
6. Sufficient organ function.

Exclusion Criteria:

1. Active infection, including tuberculosis, active or relapsed peptic ulcer, etc.
2. Severe hypogammaglobulinemia or IgA deficiency.
3. Active hepatitis or with a history of severe liver disease.
4. History of rapid allergic reactions, eczema or asthma that cannot be controlled by topical corticosteroids.
5. Severe cardiovascular diseases.
6. History of cancer within past 5 years.
7. Have other serious medical conditions.
8. Received any of B cell targeted therapies and biologic therapies within the defined time window.
9. History of severe allergies or known allergies to any active or inactive component of the study drug(s).
10. A history of organ transplantation, bone marrow transplantation or hematopoietic stem cell transplantation.