Prognostic Study on Discontinuation After Combined PEG-IFNa-2b Therapy in Chronic Phase CML Patients Who Met TKI Discontinuation Criteria Following TKI Treatment

INTERVENTION: Combination group:PEG‐IFNa‐2b plus TKI therapy;Single‐agent TKI group:TKI therapy; CONDITION: CP‐CML PRIMARY OUTCOME: Proportion of patients with loss of MMR;Proportion of TFR; SECONDARY OUTCOME: Safety evaluation;Proportion of patients achieving MR4 and MR4.5 during treatment discontinuation and after drug withdrawal;Median time to achieve MMR for patients who restart medication after relapse following treatment discontinuation; INCLUSION CRITERIA: 1.Patients diagnosed with chronic phase chronic myeloid leukemia (CP‐CML) (referring to the Guidelines for the Diagnosis and Treatment of Chronic Myeloid Leukemia (2022 Edition)); 2.Patients who met TKI discontinuation criteria after TKI therapy (discontinuation criteria are specified as follows: patients were diagnosed with chronic phase at initial diagnosis; no history of resistance to any TKI at any time point; maintained deep molecular response (DMR) for at least 2 years; patients had fully informed consent regarding treatment‐free remission (TFR) and intended to discontinue treatment voluntarily rather than under external pressure; patients fully understood that molecular relapse does not represent treatment "failure" and TKI therapy should be restarted in such cases; molecular testing could be repeated within 2–4 weeks). 3.Age < 60 years; 4.WBC < 10×10?/L, PLT < 450×10?/L; 5.All participants voluntarily signed the informed consent form.