An Investigational Study of BG-89894 Tablets in Participants With Advanced Solid Tumors

A Phase 1 Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Antitumor Activity of BG-89894 (SYH2039) Tablets in Patients With Advanced Solid Tumors

This study is being done to learn more about a new drug called BG-89894 (previously known as SYH2039). Researchers want to see if the drug is safe, how well people can tolerate it, how it moves through the body, and whether it shows any early signs of helping to treat cancer. The information gathered may help guide how future studies are designed. The entire study is expected to last about four years. People who join the study may receive treatment for around six months and will be followed for about 12 months after their treatment ends. The study plans to enroll participants over a three-year period.

Key Inclusion Criteria:

• Must sign a written informed consent and willing to comply with all study-related procedures and requirements.
• Age ≥18 years (or the legal age of consent according to local regulations).
• Histologically or cytologically confirmed diagnosis of advanced, metastatic, or unresectable solid tumors that have progressed on or after standard therapy, or for which no appropriate standard therapy is available.
• Evidence of Methylthioadenosine phosphorylase (MTAP) homozygous deletion or loss of MTAP expression in tumor tissue.
• Participants must be able to provide an archived tumor tissue sample or unstained fresh biopsy if there is no archival tissue at baseline.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and evidence of adequate organ function and bone marrow reserve, as defined in the study protocol.

Key Exclusion Criteria:

• History of other malignancies or concurrent active malignancies within 3 years.
• Prior treatment with methionine adenosyltransferase 2 alpha (MAT2A) inhibitors (e.g., AG-270, IDE397) or methylthioadenosine (MTA)-cooperative protein arginine methyltransferase 5 (PRMT5) inhibitors (e.g., AMG193).
• Uncontrolled or active central nervous system (CNS) disease, including untreated or symptomatic brain metastases, spinal cord compression, or leptomeningeal carcinomatosis.
• Active bleeding, history of major bleeding events within the past 6 months, or tumors associated with a high risk of vascular invasion.
• Receipt of systemic anticancer therapy, radiation therapy, live vaccine, or major surgical procedures within protocol-specified washout periods.
• Active or uncontrolled infections, including tuberculosis (TB), (COVID-19, known human immunodeficiency virus (HIV) infection, or uncontrolled hepatitis B virus (HBV) infection.

Note: Additional eligibility criteria may apply.