Study of NX-5948 Versus Pirtobrutinib in R/R CLL/SLL

Key Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 * Adequate organ and bone marrow function * Confirmed diagnosis of CLL/SLL that meets iwCLL 2018 criteria for diagnosis and systemic treatment * Received at least one prior line of therapy for CLL/SLL that included a cBTKi and must have documented disease progression during treatment with, or after discontinuation of, the cBTKi * Participants with SLL must have measurable disease by computed tomography (CT) per iwCLL Key Exclusion Criteria: * Known or suspected prolymphocytic leukemia or Richter's transformation at any time preceding enrollment * Investigational agent or anticancer therapy within 5 half-lives or 14 days (whichever is shorter) prior to planned start of study treatment * Ongoing systemic corticosteroids ≥10 mg/day prednisone or equivalent * Previously treated with a BTK degrader or a noncovalent BTKi * Myocardial infarction, unstable angina, unstable symptomatic ischemic heart disease, placement of a coronary arterial stent, or any other significant cardiac condition within 6 months of planned start of study treatment * Thromboembolic events, stroke, or intracranial hemorrhage within 6 months of planned start of study treatment Note: Other Inclusion/Exclusion criteria may apply as defined in the protocol.