The study is being conducted to evaluate the efficacy and safety of SHR2554 in Patients with Relapsed or Refractory Follicular Lymphoma

Inclusion Criteria:

1. Males or females aged ≥18 years
2. Histologically confirmed follicular lymphoma
3. Eastern Cooperative Oncology Group performance status (ECOG PS) score ≤2
4. Life expectancy ≥ 12 weeks
5. Treated with CD20 antibody, refractory to or relapse from prior anti-cancer therapies
6. Have measurable lesions
7. The subject is willing and able to comply with the visit schedule, dosing schedule, laboratory tests, and other clinical study procedures

Exclusion Criteria:

1. Have been treated with a compound of the same machanism;
2. Accompanied by central nervous system infiltration;
3. Received autologous stem cell transplantation within 60 days before signing the agreement, and received allogeneic stem cell transplantation or CAR-T therapy within 90 days;
4. Underwent major surgery or experienced severe trauma within 4 weeks prior to the first dose of the investigational drug
5. Known active infection
6. History of clinically severe cardiovascular diseases
7. Have other malignancies within 5 years prior to screening Pregnant or lactating women
8. The subject is unable to swallow, or has a history of active gastrointestinal inflammation, chronic diarrhea, known diverticulosis, or a history of gastrectomy or gastric banding that affects drug absorption.
9. The subject is taking a known medium or strong CYP inducer.
10. Based on the investigator's judgment, there are objective conditions that may prevent the subject from completing the study as planned or the subject has other factors, concomitant diseases, concomitant treatments, or abnormal laboratory findings that may lead to early study termination