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 adult patients with relapsed or refractory CD19-positive B-NHL, This study included dose escalation and dose expansion parts.

Key-Inclusion Criteria:

• ≥18 years and ≤75 years of age at time of informed consent
• Participants with histologically and/or cytologically confirmed relapsed or refractory CD19-positive B-cell non-Hodgkin lymphoma
• With at least one of evaluable/measurable target lesions per Lugano 2014 criteria
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2
• Life expectancy of ≥3 months
• Sufficient organ function

Key-Exclusion Criteria:

• Central nervous system lymphoma
• Previously undergone allogeneic hematopoietic stem cell transplantation or other organ transplants
• Any other prior malignancy active within the previous 5 years, except for skin basal cell cancer that has been cured, or carcinoma in situ of the cervix
• History of active autoimmune diseases
• History of interstitial lung disease, tuberculosis, or other diseases that affect pulmonary function in the past or currently
• Uncontrolled disease, including but not limited to uncontrolled diabetes, hypertension, active infections, active peptic ulcers, thromboembolic disease requiring anticoagulation, etc.
• Severe cardiovascular diseases
• History of severe allergies to protein-based drugs or any component of the study drug