Dose Determining Study of EXS73565 in Participants With Relapsed or Refractory B-Cell Malignancies

Key Inclusion Criteria:

• Age ≥18 years at the time of signing the informed consent.

• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.

• Histologically confirmed diagnosis of one of the following B-cell malignancies:chronic lymphocytic leukemia (CLL), including Richter's transformation from CLL,mantle-cell lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, ormarginal zone lymphoma.

• Participants that have relapsed after standard of care or have progressed duringstandard of care or are not suitable for standard of care therapy

Key Exclusion Criteria:

• Any medical or psychiatric condition that, in the view of the PrincipalInvestigator, could jeopardize or would compromise the participant's safety orability to participate in the study.

• Known central nervous system (CNS) malignancy or primary CNS lymphoma.

• Concurrent active or previous malignancy (other than the primary lymphoma/CLL forwhich the participant will be treated on this protocol within 5 years prior torandomization; participants with prior cancers may be enrolled with documentedSponsor approval.

• Received anticancer therapy, including chemotherapy, immunotherapy, radiationtherapy (with the exception of palliative radiotherapy), biologic therapy,cancer-related hormonal therapy, or any investigational therapy within 21 days or 5half-lives (whichever is longer) before the first dose of the study treatment.