Study of IDE397 in Participants With Solid Tumors Harboring MTAP Deletion

Inclusion Criteria:

Participant must be at least 18 years of age
Advanced or metastatic solid tumor that has progressed on at least one prior line of treatment or is intolerant to additional effective standard therapy
Have evidence of homozygous loss of MTAP or MTAP deletion
Willing to undergo paired fresh biopsy (pre- and post-treatment) procedure. Exceptions may be made for feasibility and safety concerns
Measurable disease
ECOG performance status <= 1 or 2 after discussion with medical monitor
Adequate organ function
Able to swallow and retain orally administered study treatment
Recovery from acute effects of prior therapy
Able to comply with contraceptive/barrier requirements

Exclusion Criteria:

Known symptomatic brain metastases
Known primary CNS malignancy
Current active liver or biliary disease
Impairment of gastrointestinal (GI) function
Active uncontrolled infection
Clinically significant cardiac abnormalities
Previous treatment with a MAT2A inhibitor and / or PRMT inhibitor
Systemic anti-cancer therapy or major surgery within 4 weeks prior to study entry
Radiation therapy within 2 weeks prior to study entry
Prior irradiation to >25% of the bone marrow
Current use or anticipated need for food or drugs that are known strong CYP3A4/5 inhibitors or inducers
Currently receiving another investigational study drug.
Known or suspected hypersensitivity to IDE397/excipients or components