Combination of Zanubrutinib, Rituximab and Venetoclax in Patients With Previously Untreated Follicular Lymphoma

Inclusion Criteria:

* A diagnosis of follicular lymphoma (grades 1, 2, or 3a), untreated.
* Stage II, III, or IV disease.
* Able and willing to provide written informed consent and to comply with the study protocol.
* at least one measurable disease.
* Must be in need of therapy as evidenced by at least one of the following criteria:

  * Presence of at least one B symptom: Fever (\> 38 Celsius \[C\]) not due to infectious etiology, or Night sweats, or Weight loss \> 10% in the past 6 months;
  * Fatigue due to lymphoma;
  * Splenomegaly (\> 13 cm);
  * Compression syndrome (ureteral, orbital, gastrointestinal);
  * Any of the following cytopenias, due to lymphoma: Hemoglobin ≤ 10 g/dL, or Platelets ≤ 100 x 10\^9/L, or Absolute neutrophil count (ANC) \< 1.5 x 10\^9/L;
  * Pleural or peritoneal effusion;
  * Lactate dehydrogenase (LDH) \> upper limit of normal (ULN) or beta (B)2 microglobulin \> ULN;
  * Other lymphoma-mediated symptoms as determined by the treating physician.
* ECOG ≤ 2
* ANC \> 1.0 x 10\^9/L (for patients without bone marrow involvement by lymphoma)
* Platelet count \> 50 x 10\^9/L (for patients without bone marrow involvement by lymphoma)
* Prothrombin time (PT)/international normal ratio (INR) \< 1.5 x (upper limit of normal) ULN and partial thromboplastin time (PTT) (activated partial thromboplastin time \[aPTT\]) \< 1.5 x ULN (unless abnormalities are unrelated to coagulopathy or bleeding disorder). When treated with warfarin or other vitamin K antagonists, then INR ≤ 3.0)
* Serum aspartate transaminase (AST) and alanine transaminase (ALT) \< 3 x ULN
* Creatinine clearance \> 30 ml/min calculated by modified Cockcroft-Gault formula
* Bilirubin \< 1.5 x ULN unless bilirubin is due to Gilbert's syndrome, documented liver involvement with lymphoma, or of non-hepatic origin, in which case bilirubin should not exceed 3 g/dL
* Women of childbearing potential must have a negative serum (beta-human chorionic gonadotropin \[B-hCG\]) pregnancy test at screening. Women who are pregnant or breastfeeding are ineligible for this study

Exclusion Criteria:

* Known active central nervous system lymphoma or leptomeningeal disease
* Follicular lymphoma with evidence of diffuse large B-cell transformation
* Grade 3b follicular lymphoma
* Any prior history of other malignancy besides follicular lymphoma
* History of severe allergic or anaphylactic reactions to monoclonal antibody therapy
* Patients who have undergone major surgery within 14 days
* The researchers believe that it is not advisable for the participant to take part in this trial.