Evaluation of Rovadicitinib Compared to the Protocol Selected by Researchers in Third Line and Subsequent Studies of Moderate to Severe Chronic Graft-versus-host Disease

Inclusion Criteria: * Age: 18 to 70 years old; Karnofsky (KPS) ≥ 60 points; Expected survival period exceeding 6 months; * Previously received allogeneic hematopoietic stem cell transplantation; * According to NIH standards, the clinical diagnosis is moderate to severe cGVHD； * Previously received systematic treatment for cGVHD with 2-5 lines; * Stable dosage of corticosteroids and other immunosuppressants received within 2 weeks prior to screening; * The main organ functions well; * Starting from Day 1 after enrollment in the control group of this study, participants must receive one of the drugs specified in the study protocol; * Female participants of childbearing age should agree to use contraceptive measures (such as intrauterine devices, birth control pills, or condoms) during the study period and for 6 months after the end of the study; Serum pregnancy test negative within 7 days prior to enrollment in the study, and must be a non lactating subject; Male participants should agree to use contraceptive measures during the study period and within 6 months after the end of the study period; * Subjects voluntarily joined this study, signed informed consent, and had good compliance. Exclusion Criteria: * Has experienced or currently suffers from other malignant tumors within the past 3 years; * Known or suspected active aGVHD； * Individuals with interstitial pneumonia, non infectious pneumonia, uncontrolled active infections, or infections requiring systematic treatment within the first 7 days of randomization, except for those deemed suitable for inclusion by the researchers; * The occurrence and progression of other underlying diseases include post transplant lymphoid tissue proliferative diseases and recurrence of primary malignant hematological diseases; * Random failure of allogeneic hematopoietic stem cell transplantation within the first 6 months or having received 2 allogeneic hematopoietic stem cell transplants in the past; * Used JAK inhibitors, Bruton's tyrosine kinase (BTK) inhibitors, etc. within the first 2 weeks of randomization; * There are multiple factors that can affect oral medication, such as inability to swallow, intestinal obstruction, etc; * Individuals with a history of abuse of psychotropic drugs who are unable to quit or have mental disorders; * Subjects with any severe and/or uncontrolled illnesses; * Individuals who are allergic to research drugs or their components; * Participated in other clinical trials within the first 4 weeks of randomization; * According to the researcher's judgment, there are accompanying diseases that seriously endanger the safety of the subjects or affect the completion of the study, or subjects who are deemed unsuitable for inclusion due to other reasons.