The primary objectives of this trial are to evaluate the safety profile of AMG 436 and to determine the maximum tolerated dose (MTD) and/or the recommended dose for AMG 436 as monotherapy and in combination with other anti-cancer therapies in participants with MSI-H/dMMR solid tumors.

Inclusion Criteria:

• Age ≥ 18 years (or ≥ legal age within the country if it is older than 18 years).
• Histologically confirmed MSI-H or dMMR metastatic or locally advanced solid tumor by local testing or central testing.
• Tumor tissue (formalin-fixed, paraffin-embedded sample) archival block must be available. Participants without archived tumor tissue may enroll by undergoing tumor biopsy before dosing.
• Disease measurable as defined by Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1).
• Eastern Cooperative Oncology Group performance (ECOG) 0-1.
• Adequate organ function as defined in the protocol.

Exclusion Criteria:

• Participants with primary central nervous system (CNS) tumors.
• Impaired cardiac function or clinically significant cardiac disease.
• Major surgery within 28 days of trial day 1.
• Antitumor therapy (chemotherapy, antibody therapy, molecular targeted therapy, hormonal therapy, or investigational agent) within 21 days of first dose of trial treatment, unless anti-tumor therapy is a therapy with 5 times the half-life being shorter than 21 days (in this case, enrollment may be allowed with washout from prior therapy of < 21 days.
• Radiation therapy within 28 days of the first dose of trial treatment (or local or focal radiotherapy with palliative intent within 14 days of the first dose).
• Gastrointestinal tract disease causing the inability to take per os (PO) medication, malabsorption syndrome, requirement for intravenous (IV) alimentation, uncontrolled inflammatory gastrointestinal disease (eg, Crohn's disease, ulcerative colitis).

De-identified individual patient data for variables necessary to address the specific research question in an approved data sharing request.

Data sharing requests relating to this trial will be considered beginning 18 months after the trial has ended and either 1) the product and indication have been granted marketing authorization in both the US and Europe or 2) clinical development for the product and/or indication discontinues and the data will not be submitted to regulatory authorities. There is no end date for eligibility to submit a data sharing request for this trial.

Qualified researchers may submit a request containing the research objectives, the Amgen product(s) and Amgen trial/trials in scope, endpoints/outcomes of interest, statistical analysis plan, data requirements, publication plan, and qualifications of the researcher(s). In general, Amgen does not grant external requests for individual patient data for the purpose of re-evaluating safety and efficacy issues already addressed in the product labelling. Requests are reviewed by a committee of internal advisors. If not approved, a Data Sharing Independent Review Panel will arbitrate and make the final decision. Upon approval, information necessary to address the research question will be provided under the terms of a data sharing agreement. This may include anonymized individual patient data and/or available supporting documents, containing fragments of analysis code where provided in analysis specifications. Further details are available at the URL below.