This study will evaluate the safety, tolerability, pharmacokinetics, and activity of XmAb24306 alone or in combination with a checkpoint inhibitor treatment in participants with locally advanced or metastatic solid tumors.

Key General Inclusion Criteria

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
• Life expectancy >/= 12 weeks
• Adequate hematologic and end-organ function
• For participants receiving therapeutic anticoagulation: stable anticoagulant regimen
• Negative serum pregnancy test for women of childbearing potential
• Histologically confirmed locally advanced, recurrent, or metastatic incurable solid tumor malignancy
• Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
• Availability of representative tumor specimens

Key General Exclusion Criteria

• Pregnant or breastfeeding, or intending to become pregnant during the study
• Significant cardiovascular disease
• Current treatment with medications that prolong the QT interval
• Known clinically significant liver disease
• Poorly controlled Type 2 diabetes mellitus
• Symptomatic, untreated, or actively progressing CNS metastases
• History of leptomeningeal disease
• History of malignancy other than disease under study within 3 years prior to screening
• Active or history of autoimmune disease or immune deficiency
• Active tuberculosis, hepatitis B, hepatitis C, or known/suspected Epstein Barr virus infection
• Positive for HIV infection
• Prior allogeneic stem cell or solid organ transplantation

For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing