Surovatamig as Consolidation Therapy in Participants With Chronic Lymphocytic Leukaemia or Small Lymphocytic Lymphoma With Unmutated Immunoglobulin Heavy Chain Variable (IGHV)

Inclusion Criteria:

* Documented diagnosis of CLL/SLL with genomic features defined by unmutated IGHV.
* Treatment received and response at the end of 1L (first-line) finite therapy.
* Participants with SLL (except those in CR in Phase III part) must have measurable disease (nodal or extranodal) with at least one measurable target lesion.
* ECOG performance status of 0 to 2.
* Adequate haematologic, liver, renal and cardiac function.
* Female participants: must be either women not of childbearing potential or must use a highly effective form of contraception.
* Male participants who intend to be sexually active with females of childbearing potential must agree to use barrier contraception (eg, condoms).

Exclusion Criteria:

* Suspected or confirmed transformation of CLL/SLL to a more aggressive form of lymphoma (ie, Richter's transformation, prolymphocytic leukaemia, or DLBCL).
* Evidence of active or history of Central Nervous System (CNS) involvement by CLL/SLL.
* History of or ongoing confirmed progressive multifocal leukoencephalopathy.
* Participants who have any concurrent or history of malignancy.
* Participants with:
* Active or uncontrolled infection (including Epstein-Barr virus-EBV) requiring systemic therapy.
* Participants with known history of Heamophagocytic lymphohistiocytosis (HLH).
* Human Immunodeficiency Virus (HIV) infection, or participants with chronic or active infection with Hepatitis B Virus (HBV) or Hepatitis C Virus (HCV).
* Major cardiac abnormalities.
* Prior CLL/SLL-specific therapies.
* Requires chronic immunosuppressive therapy for active autoimmune/inflammatory condition or prior allogeneic stem cell or solid organ transplant.
* Major surgical procedure.
* Known hypersensitivity to surovatamig or any of the excipients of the product.