Efficacy and Safety of MegaLT Injection for Platelet Recovery After Umbilical Cord Blood Transplantation

Inclusion Criteria: * Age ≥18 years, male or female. * Patients with a definite diagnosis of hematologic malignancy who are undergoing umbilical cord blood transplantation. * Patients at day 14 after umbilical cord blood transplantation. * ECOG performance status ≤2. * Patients who voluntarily agree to participate in this clinical trial, fully understand the study content, and sign the informed consent form. Exclusion Criteria: * Patients with relapse of any malignant tumor. * Pregnant or lactating women. * Patients with severe infection or severe cardiac, hepatic, pulmonary, renal, neurologic, or metabolic disease. * Patients with a history of severe thrombotic events or known risk factors for thrombosis. Exception: participants for whom the investigator determines that the potential benefit of study participation outweighs the potential risk of thromboembolic events. * Patients with uncontrolled infectious disease or other serious diseases, including but not limited to infection such as HIV positivity, congestive heart failure, unstable angina, cardiac arrhythmia, psychosis, social circumstances that would limit compliance with study requirements, or any condition that the treating physician considers may pose unpredictable risks. * Patients with active hepatitis B or hepatitis C. * Patients who have previously received organ transplantation or are planning to receive organ transplantation, except for hematopoietic stem cell transplantation. * Patients who participated i…