A Study of NX-5948 in Adults With CLL/SLL Previously Treated With a Bruton's Tyrosine Kinase Inhibitor and a B-cell Lymphoma-2 Inhibitor (DAYBreak CLL-201)

Inclusion Criteria:

• Age: ≥ 18 years

• Confirmed relapsed/refractory CLL/SLL that meets iwCLL criteria for diagnosis andsystemic treatment

• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

• Must have received a covalent BTK inhibitor (BTKi), a non-covalent BTKi, and a BCL-2inhibitor either in separate lines of treatment or in combination

• Measurable disease by radiographic assessment

• Adequate organ and bone marrow function

• Must sign an informed consent form indicating that he or she understands the purposeof the procedures required for the study and is willing to participate

Exclusion Criteria:

• Known or suspected prolymphocytic leukemia or Richter's transformation beforeentering study

• Investigational agent or anticancer therapy within 5 half-lives or 14 days (whichever is shorter) before planned start of study drug

• Antibody therapy must stop at least 4 weeks before the first dose of study drug

• No other systemic anticancer therapy is allowed at the same time as this study;exception: continuation of hormonal therapy for breast and prostate cancer isallowed, if they are not on the list of prohibited concomitant medications inthis study

• Radiotherapy within 2 weeks of the first dose of study drug except for focalpalliative radiation

• Use of systemic corticosteroids >20 mg/day prednisone or equivalent within the 7days before start of study drug except for those used as premedication for radiodiagnostic contrast

• Use of systemic immunosuppressive drugs other than systemic corticosteroids within 60 days before the first dose of study drug

• Previously treated with a BTK degrader

• Previous chimeric antigen receptor (CAR) T-cell therapy or autologous hematopoieticcell transplant <1 year prior to enrollment

• Thromboembolic events (eg, deep vein thrombosis, pulmonary embolism, or symptomaticcerebrovascular events), stroke, or intracranial hemorrhage within 6 months ofplanned start of study drug

Note: Other Inclusion/Exclusion criteria may apply as defined in the protocol.