Inclusion Criteria:  Participant has provided informed consent/assent before initiation of any study specific activities/procedures. Age ≥ 18 years. Evidence of homozygous loss of cyclin dependent kinase inhibitor 2A (CDKN2A) (null) and/or methylthioadenosine phosphorylase (MTAP) (null) or lost MTAP expression in the tumor tissue. Histologically confirmed metastatic or locally advanced solid tumor not amenable to curative treatment with surgery and/or radiation. Able to swallow and retain orally (PO) administered study treatment and willing to record daily adherence to investigational product. Disease measurable as defined by Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1). Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. Adequate hematopoietic function per local laboratory. Adequate renal function per local laboratory. Adequate glucose control per local laboratory (Part 1 only). Adequate liver function per local laboratory. Adequate coagulation parameters. Adequate pulmonary function. Adequate cardiac function. Minimum life expectancy of 12 weeks as per investigator judgement. Tumor tissue must be available.  Exclusion Criteria:  Spinal cord compression or active brain metastases or leptomeningeal disease from non-brain tumors. Presence of primary brain cancer. Presence of hematological malignancy or lymphoma. History of other malignancy within the past 2 years. Evidence of lung disease. Active infection. History of arterial thrombosis. Myocardial infarction and/or symptomatic congestive heart failure, unstable angina, or cardiac arrhythmia. Gastrointestinal tract disease. History of solid organ transplant. Diagnosis of Congenital Short QT Syndrome. Prior treatment with an methionine adenosyltransferase 2α (MAT2A) inhibitor or a protein arginine methyltransferase 5 (PRMT5) inhibitor. Prior irradiation to greater than 25% of the bone marrow. Unresolved toxicity from prior anti-cancer therapy. Currently receiving treatment in another investigational device or drug study. Known positive test for Human Immunodeficiency Virus. Evidence of hepatitis B or C infection. Female participants of childbearing potential with a positive pregnancy test.