This is a Phase I/II, multicenter, open-label study to evaluate the safety, efficacy, tolerability, and pharmacokinetics of a novel BTK inhibitor, Orelabrutinib (ICP-022) in Patients with B-cell malignancies. The study contains two parts, Part 1 (dose escalation) and Part 2 (dose expansion).

Inclusion Criteria:

1. Signed Informed Consent.

2. Age ≥ 18 years.

3. Part 1: Patients with histologically confirmed relapsed or refractory B-cell malignancies, including Grades 1-3a FL, MZL, MCL, and CLL/SLL.

   Part 2: Patients with histologically confirmed B-cell malignancies including r/r FL, r/r MZL and CLL/SLL with/without prior treatment.

4. Life expectancy (in the opinion of the investigator) of ≥ 4 months.

5. ECOG performance status of 0 ~1.

6. Must have adequate organ function.

7. Negative test results for HBV ([HBsAg (-)] and non-active HBV or HCV infection

Exclusion Criteria:

1. Pregnant or breast-feeding or intending to become pregnant during the study.
2. Prior treatment with systemic immunotherapeutic agents.
3. Known allergies to Orelabrutinib (ICP-022) or its excipients or infection with HIV.
4. Treatment with any chemotherapeutic agent, or any other investigational therapies within 4 weeks prior to first dose of the study drug.
5. History of allogeneic stem-cell (or other organ) transplantation or confirmed progressive PML.
6. Any external beam radiation therapy within 6 weeks prior to the first dose of the study drug.
7. Concurrent use of warfarin or other vitamin K antagonists or anticoagulation therapies or strong CYP3A inhibitor.
8. Active uncontrolled infections.
9. Recent infection requiring IV anti-infective treatment that was completed ≤ 14 days before the first dose of study drug.
10. Unresolved toxicities from prior anti-cancer therapy.
11. Medically apparent CNS lymphoma or leptomeningeal disease.
12. Current or previous history of CNS disease.
13. Major surgery or significant traumatic injury < 28 days prior to the first dose of the study drug.
14. Patients with another invasive malignancy in the last 2 years.
15. Significant cardiovascular disease or active pulmonary disease.
16. Received systemic immunosuppressive medications.