A Single-arm Phase 2 Prospective Clinical Study of Enatumab in the Treatment of Relapsed/Refractory Warm Antibody Autoimmune Hemolytic Anemia

Inclusion Criteria: 1. Age ≥18 years old, gender not limited. 2. Primary wAIHA with a clear diagnosis. 3. Patients who have relapsed or are refractory after at least second-line treatment (previous treatments include at least two types of glucocorticoids, CD20 monoclonal antibodies or other immunosuppressants). Refractory is defined as failure to achieve partial remission after 6 months of treatment with a stable dose of immunosuppressants. 4. The infusion of CD20 monoclonal antibody should be at least three months apart. If taking immunosuppressants such as cyclosporine and sirolimus, the medication should be discontinued for at least one month. 5. Hemoglobin (HGB) ≤100g/ and ≥ 60g/L. 6. Before treatment, the patient's alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were less than 3 times the upper limit of normal (ULN), and the serum creatinine was less than 1.5 times ULN. 7. Voluntarily join this study, sign the informed consent form with good compliance, and be willing to cooperate with regular follow-ups for efficacy evaluation and side effect monitoring. Exclusion Criteria: * (1) Those with impaired functions of organs such as the heart, liver and lungs; Patients with acute renal insufficiency. (2) Patients with connective tissue diseases and other secondary AIHA. (3) There is an active infection of hepatitis B virus (HBV), hepatitis C virus (HCV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), human immunodeficiency virus (HIV), or any uncontrolled bacterial, fungal or viral infection. (4) Complicated with malignant tumors or a history of tumors. (5) When screening, the subjects had other types of uncorrected anemia, such as nutritional anemia, etc. (6) Had received other BCMA-targeted or CART treatments before screening. (7) Pregnant or lactating women. (8) Activity ≥ grade 2 peripheral sensory/motor neuropathy. (9) Had received treatment with other experimental drugs within 30 days (or as required by local regulations) or within 5 half-lives (whichever is longer) prior to the first use of the intervention drug in this study.