A Study of NX-5948 in Adults With Relapsed/Refractory B-cell Malignancies

Phase 1a is a dose escalation to evaluate the safety and tolerability of NX-5948 in adult patients with relapsed/refractory (R/R) B cell malignancies who have received at least 2 prior lines of therapy, or at least 1 prior line of therapy for Primary Central Nervous System Lymphoma (PCNSL), and for whom no other therapies are known to provide clinical benefit. Indications include: Chronic Lymphocytic Leukemia (CLL), Small Lymphocytic Lymphoma (SLL), Diffuse Large B-cell Lymphoma (DLBCL), Mantle Cell Lymphoma (MCL), Waldenstrom Macroglobulinemia (WM), Marginal Zone Lymphoma (MZL), Follicular Lymphoma (FL), Primary Central Nervous System Lymphoma (PCNSL) or any of the above indications with disease in the central nervous system or Secondary Central Nervous System Lymphoma (SCNSL). Phase 1b Part 1, called safety expansion, investigates the safety and anti-tumor activity of NX-5948 at the dose(s) selected in Phase 1a in up to 17 expansion cohorts of patients with histologically confirmed B-cell malignancy indications who have received specified prior therapies based on indication: * CLL or SLL (patients may be randomized to one of two dose levels investigated for CLL/SLL until an optimal dose is selected) * MCL * MZL * WM * DLBCL * FL * PCNSL/SCNSL Phase 1b Part 2, called cohort expansion, will further investigate the anti-tumor activity of NX-5948 at the dose(s) selected in Phase 1b par 1 in one additional expansion arm of CLL/SLL patients.