This is a randomized, multicenter, open-label, Phase 3 study to evaluate the efficacy and safety of ICP-022 versus Chlorambucil plus Rituximab in subjects with Previously Untreated Chronic Lymphocytic Leukemia.

Key Inclusion Criteria:

1. Male or female, age ≥65 years old or age >18 years old or <65 years old, age >18 years old or <65 years old shall meet any of the following criteria simultaneously: A.Disease accumulation score (CIRS) > 6;B. Creatinine clearance at 30-69 mL/ min (Cockcroft-Gault assessment)
2. Enhanced computed tomography/magnetic resonance imaging (CT/MRI) detection had measurable lesions: at least one lymph node had a maximum axis of more than 1.5 cm and had a measurable vertical dimension
3. ECOG physical strength score is 0-2.
4. Expected survival time >6 months.
5. Voluntary written informed consent prior to screening.

Key Exclusion Criteria:

1. Patients with stroke or intracranial hemorrhage in the first 6 months were randomly assigned.
2. Hypersensitivity to ICP-022, nitrogen mustard benzoate, rituximab or any other component of the applicable study drug.
3. Any mental or cognitive impairment that may limit their understanding of the informed consent, their implementation and their compliance with the study.
4. Pregnant and lactating women, or subjects of childbearing age who do not want to use contraception within 180 days from the end of the study period to the end of the study period.
5. Conditions in which a potentially life-threatening illness or severe organ dysfunction is not considered appropriate by the investigator.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.