TQB3909 Tablets in Subjects With Relapsed or Refractory Mantle Cell Lymphoma (MCL)

Inclusion Criteria: * The subject voluntarily joins the study, signs the informed consent form, and has good compliance; * Age: ≥ 18 years old (when signing the informed consent form); Eastern Cooperative Oncology Group performance status (ECOG PS) score: 0-2 points; Expected survival is more than 3 months; * Subject population: Confirmed as MCL by local laboratory pathology and independent pathology review (stage 2). * The main organs are functioning well, * The patient's Computed Tomography (CT) / Magnetic Resonance Imaging (MRI) shows measurable lesions, defined as ≥ 1 lymph node with the longest diameter of \> 1.5 cm or ≥ 1 extranodal lesion with the longest diameter of \> 1.0 cm, which can be measured by ≥ 2 vertical dimensions; * Female subjects of childbearing age should agree to use contraception (e.g., pills, or condoms) during the study and for 6 months after the end of the study; Have a negative serum pregnancy test within 7 days prior to study enrollment and must be a non-lactating subject; Male participants should agree that contraception must be used during the study period and for 6 months after the end of the study period. Exclusion Criteria: * Have had or currently have other malignant tumors within 3 years before the first dose of study drug. * It is known that lymphoma affects the central nervous system (CNS); * Previous allogeneic hematopoietic stem cell transplantation; * Have received autologous hematopoietic stem cell transplantation within 3 months …