Inclusion Criteria:

• Signed written informed consent granted prior to initiation of any study-specific procedures. 
• 18 years of age and older.
• For the dose escalation cohorts, relapsed or refractory subjects with a diagnosis of B-cell NHL, CLL/SLL and WM who have received at least two prior systemic therapies . Subjects must have failed or are intolerant to standard therapies and cannot be a candidate for standard salvage regimens. Subjects with low grade lymphoma must be progressing and requiring treatment.. 
• For the expansion cohorts, the following criteria must be met:
  • Cohort A: Relapsed/Refractory (R/R) CLL/SLL subjects with at least 2 prior systemic therapies and previously treated with a covalent BTKi who must have a documented BTK mutation on C481 residue;
  • Cohort B: R/R CLL/SLL subjects who have failed or were intolerant to a BTKi with documentation of the absence of BTK mutation on C481 residue. In this study, intolerance to standard therapy is defined as having experienced a grade 3 or higher adverse event that was caused by the standard therapy and resulted in treatment discontinuation;
  • Cohort C: Richter's transformation subjects who have failed at least one prior therapy;
  • Cohort D: Follicular Lymphoma (FL) subjects who have failed at least 2 prior systemic therapies and are histology grade 1, 2, or 3A;
  • Cohort E: Mantle Cell Lymphoma (MCL) subjects who have failed at least 2 prior systemic therapies;
  • Cohort F: Marginal Zone Lymphoma (MZL) subjects who have failed at least 2 prior systemic therapies;
  • Cohort G: High-grade B-cell lymphoma subjects who have failed at least 2 prior systemic therapies and have known MYC and BCL2 and/or BCL6 translocations;
  • Cohort H: Waldenström macroglobulinemia (WM) subjects who have failed at least 2 prior systemic therapies.
• Disease status requirement: 
  • For CLL subjects, symptomatic disease that mandates treatment (Hallek et al. 2018); 
  • For B-cell NHL subjects, measurable disease by imaging scan;
  • For WM, serum immunoglobulin M (IgM) with a minimum IgM level of ≥ 2 times the upper limit of normal (ULN). 
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. 
• Good organ function:
  • Creatinine clearance of ≥ 60 mL/min as estimated by the Cockcroft-Gault equation or by 24-hour urine collection;
  • Total bilirubin ≤ 1.5 x institutional ULN (total bilirubin of ≤ 3 x institutional ULN in subjects with documented Gilbert's syndrome);
  • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × institutional ULN;
  • Platelet count ≥ 50,000/µL;
  • Absolute neutrophil count (ANC) ≥ 1000/µL;
  • Hemoglobin (Hgb) ≥ 8.0 g/dL, stable for ≥ 1 week.
• For men and women of child-bearing potential, willing to use adequate contraception (e.g., latex condom, cervical cap, diaphragm, abstinence, etc.) for the entire duration of the study.
• Female subjects of child-bearing potential must have a negative serum pregnancy test within 14 days of the first day of drug dosing.
• Ability to swallow oral medications without difficulty.

Exclusion Criteria:

• Had immunotherapy, radiotherapy, radioimmunotherapy, biological therapy, chemotherapy, or treatment with an investigational product within 5 half-lives or four weeks (whichever is shorter) prior to treatment initiation, or oral therapy within 5 half-lives or one week (whichever is shorter) prior to treatment initiation. 
• Transformation of FL to a more aggressive subtype of lymphoma or grade 3b FL.
• Subjects currently being treated with the following drugs:
  • CYP 2C9 substrates with a narrow therapeutic index (such as warfarin, phenytoin);
  • CYP 2C8 substrates with a narrow therapeutic index (such as paclitaxel);
  • CYP 2C19 substrates with a narrow therapeutic index (such as S-mephenytoin);
  • CYP 2D6 substrates with a narrow therapeutic index (such as thioridazine, pimozide);
  • P-gp substrates with a narrow therapeutic index (such as digoxin)
    • Note: A washout period of at least 5 times the half-life after the last dose of any of the above treatments is required for a subject to be eligible for study enrollment. 
• Prior allogeneic bone marrow transplant. 
• Active central nervous system (CNS) involvement. 
• Pregnant or breast-feeding women. 
• Has significant, ongoing co-morbid conditions which would preclude safe delivery of the study drug. 
• Uncontrolled illness including but not limited to ongoing or active infection, symptomatic congestive heart failure (New York Heart Association [NYHA] Class III or IV heart failure), unstable angina pectoris, cardiac arrhythmia, cardiac infarction in the past six months, and psychiatric illness that would limit compliance with study requirements. 
• QTc prolongation (defined as a QTc > 450 msecs) or other significant electrocardiogram (ECG) abnormalities including 2nd degree atrioventricular (AV) block type II, 3rd degree AV block, or bradycardia (ventricular rate less than 50 beats/min). If the screening ECG has a QTc > 450 msecs, the ECG can be submitted for a centralized, cardiologic evaluation. 
• Active human immunodeficiency virus (HIV) infection, Hepatitis B, or Hepatitis C infection. 
• Other medical or psychiatric illness or organ dysfunction which, in the opinion of the Investigator, would either compromise the subject's safety or interfere with the evaluation of the safety of the study agent.
• History of prior cancer within < 1 year, except for basal cell or squamous cell carcinoma of the skin, cervical cancer in situ or other in situ carcinomas.