Basiliximab Combined With Ruxolitinib as Second-line Treatment of Grade 3-4 Steroid-resistant aGVHD

Inclusion Criteria: * Clinical diagnosis of primary grade 3-4(according to MAGIC criteria) steroid-resistant acute graft-versus-host disease(progression after 3 days or lack of improvement after 5 days of systemic 1.5-2 mg/kg steroids). * Age 18-65. * ECOG score≤3. * Must be able to understand and willing to participate in the study and sign the informed consent. Exclusion Criteria: * Refractory/secondary graft-versus-host disease. * Severe complications such as myocardial infarction, chronic cardiac insufficiency, hepatic failure, renal insufficiency, etc. * Clinically uncontrolled active infections. * Other Malignant tumors with progression. * Ecg: QT interval \> 450 ms. * Allergic to arsenic agent. * Pregnant or lactating women. * Expected survival \<60 days. * Undergoing other drug clinical trials.