A Phase 1b Study of Oral AS-1763 in Patients With Previously Treated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma or Non-Hodgkin Lymphoma

Inclusion Criteria: * Age ≥18 years * Provided written informed consent * Histologically confirmed B-cell malignancy, including CLL/SLL, WM, MCL, MZL, or FL * Patients with SLL, MCL, MZL, and FL: at least 1 radiographically measurable lesion * Failed or are intolerant to ≥2 prior lines of systemic therapy * ECOG Performance Status 0 to 2 * Adequate hematologic status (ie, absolute neutrophil count ≥0.75 × 10⁹/L, platelet count ≥50 × 10⁹/L, hemoglobin ≥8 g/dL) not requiring transfusion support or growth factors * Adequate hepatic function * Adequate renal function * Ability to swallow tablets and comply with study requirements for the duration of study participation * Male and female patients of reproductive potential: Willing to observe conventional and effective birth control methods * Male patients: agree not to donate sperm during and for 6 months after the study * Dose Expansion Cohort 3 patients: prior treatment with pirtobrutinib (Jaypirca) for an approved indication Exclusion Criteria: * Transformed disease (eg, Richter's transformation) prior to or during Screening * Investigational agent or anticancer therapy within 5 half-lives before the planned start of docirbrutinib, except therapeutic monoclonal antibody treatment which must be discontinued at least 4 weeks before the start of docirbrutinib * Current treatment with investigational therapy or planned investigational therapy which would be concurrent with this study * Requiring therapeutic anticoagulation with warfarin * Current treatment with certain strong CYP3A4 inhibitors or inducers * Treatment with proton pump inhibitors within 7 days before first dose of docirbrutinib * Current treatment with strong P-glycoprotein inhibitors or strong BCRP inhibitors * Refractory to transfusion support * Major surgery within 4 weeks before planned start of docirbrutinib * Radiotherapy with a limited field of radiation for palliation within 7 days of the first dose of study treatment * Any unresolved toxicities from prior therapy greater than NCI CTCAE Version 5.0 Grade 2 at the time of starting study treatment except for alopecia * History of allogeneic or autologous stem cell transplant or CAR-T therapy within the last 30 days * Active second malignancy unless in remission with life expectancy \>2 years * Known central nervous system (CNS) involvement by systemic lymphoma * Active uncontrolled autoimmune cytopenia (eg, autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura) where new therapy introduced or concomitant therapy escalated within the 4 weeks before study enrollment is required to maintain adequate blood counts * Clinically significant, uncontrolled cardiac, cardiovascular disease or history of myocardial infarction within 6 months before planned start of docirbrutinib, or prolongation of the QT interval corrected for heart rate using Fridericia's Formula (QTcF) \>470 msec on at least 2 of 3 consecutive ECGs, and mean QTcF \>470 msec on all 3 ECGs, during Screening * Active uncontrolled systemic bacterial, viral, fungal, or parasitic infection * Positive for HIV. For patients with unknown HIV status, HIV testing will be performed at Screening * Clinically significant active malabsorption syndrome or other condition likely to affect gastrointestinal absorption of docirbrutinib * Pregnant or lactating. * Known hypersensitivity to any component or excipient of docirbrutinib * Prior treatment with docirbrutinib * Dose Escalation and Cohort 3 patients: prior treatment with noncovalent BTKi except pirtobrutinib (Jaypirca) * Dose Expansion Cohort 1 and Cohort 2 patients: prior treatment with any noncovalent BTKi