Evaluate the Efficacy and Safety of Interferon-α Combined With ATO in the Treatment of Arsenic-resistant APL

Inclusion Criteria: * 1\. Must sign an informed consent form (ICF) indicating that he or she understands the purpose of, and procedures required for, the study and is willing to participate in the study. * 2\. Age 18-70 years old (including boundary value); * 3\. The presence of promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα) confirmed by morphological features, cytogenetic analysis, and real-time quantitative polymerase chain reaction (qPCR); * 4\. Arsenic relapse resistant patients: patients who had relapsed (including molecular relapse) after remission with ATO in the previous treatment, and could not be relieved after standard treatment; * 5\. Eastern Cooperative Oncology Group (ECOG) performance status score 0-2; * 6\. The expected survival time is more than 3 months. Exclusion Criteria: * 1\. Allergy or contraindication to any study drug involved in the protocol; * 2\. Physical examination, electrocardiogram, laboratory examination, vital signs and test related abnormalities are clinically significant (subject to clinician's judgment); * 3\. Other serious conditions that may limit the patient's participation in the trial, such as severe liver or kidney disease; "Patients with advanced infection, uncontrolled diabetes mellitus, severe cardiac dysfunction (e.g., clinically significant prolongation of the QT interval, potentially fatal torsades de pointes) or a history of angina or major heart disease, autoimmune diseases (as judged by the clinician);" * …