Pegylated Interferon α-2b in Combination With Ruxolitinib for Treating Hydroxyurea-resistant/Intolerant PV

Inclusion Criteria:

• ≥18 years old.

• Male or Female.

• Meets the diagnostic criteria for Polycythemia Vera according to WHO-2022.

• Resistant or intolerant to hydroxyurea (based on the 2013 European LeukemiaNetcriteria).

• Have not previously received interferon preparations or ruxolitinib treatment, orthe washout period between the last use of interferon preparations or ruxolitiniband the first use of the study drug should not be less than 4 weeks.

• Patients with indications for cytoreductive therapy.

• During screening, female hemoglobin (HGB) ≥10g/dL, male hemoglobin (HGB) ≥11g/dL;neutrophil count ≥1.5×109/L; platelet count ≥100×109/L.

• Voluntary written informed consent.

Exclusion Criteria:

• Symptomatic splenomegaly;

• Contraindications to interferon or ruxolitinib therapy;

• Severe or significant comorbidities that may affect the participant's ability toparticipate in the study, as determined by the investigator;

• History of major organ transplantation;

• Pregnant or breastfeeding women;

• History or current diagnosis of autoimmune thyroid disease (patients with controlledhypothyroidism on oral thyroid hormone replacement therapy may be included);

• Documented evidence of any other autoimmune disease (such as active hepatitis,systemic lupus erythematosus, antiphospholipid antibody syndrome, or autoimmunearthritis);

• Clinically significant bacterial, fungal, mycobacterial, parasitic, or viralinfection such as active hepatitis or HIV infection (patients with acute bacterialinfections requiring antibiotic treatment should be deferred fromscreening/enrollment until completion of antibiotic treatment);

• Evidence of severe retinopathy or clinically significant ophthalmologic disease (dueto diabetes or hypertension);

• Current clinically significant depression or history of depression, or any suicidalattempt or tendency during screening;

• Active bleeding or thrombotic complications;

• History of any malignant tumor within the past 5 years (except for stage 0 chroniclymphocytic leukemia [CLL], cured basal cell carcinoma, squamous cell carcinoma, andsuperficial melanoma);

• History of alcohol or substance abuse within the past year;

• Presence of blasts in the peripheral blood within the past 3 months;

• Use of any investigational drug or participation in any other clinical trial within 4 weeks prior to the first dose of the study drug, or failure to recover from anyeffects of previously administered study drugs;

• The investigator deems the presence of any concurrent condition that may jeopardizethe safety of the participant or the compliance to the protocol.