Inclusion Criteria:

• * Having signed the written Informed Consent Form
• * Male or female aged ≥18 years
• * Life expectancy ≥12 weeks
• * Eastern Cooperative Oncology Group (ECOG) Performance Score 0 or 1
• * Dose escalation phase: Histologically or cytologically confirmed locally advanced or metastatic mesothelioma (MM), epithelioid hemangioendothelioma (EHE), or other advanced solid tumors who have experienced progressive disease or treatment intolerability after receiving the standard-of-care, or refuse to receive or have no access to the standard-of-care
• * Dose expansion phase: Histologically or cytologically confirmed locally advanced or metastatic MM, EHE, etc. regardless of Hippo signaling pathway abnormalities, or other advanced solid tumors with Hippo signaling pathway abnormalities, who have experienced progressive disease or treatment intolerability after receiving the standard-of-care, or refuse to receive or have no access to the standard-of-care
• * At least one measurable lesion

Exclusion Criteria:

• * Previous or current use of transcriptional enhanced associate domain (TEAD) inhibitors
• * Inadequate wash-out of prior therapies described per protocol
• * Patients with severe or unstable systemic disease, unstable or symptomatic Central Nervous System (CNS) metastasis
• * Clinically significant cardiovascular disease as defined in the protocol
• * Women who are pregnant or breastfeeding
• * Hypersensitivity to the active pharmaceutical ingredient or any excipient of BGC515
• * Study staff member or relative of a study staff member directly related to this clinical trial, or a subordinate of the Investigator in this trial or an employee of the Sponsor, though not directly related to this trial
• * Serious systemic diseases or laboratory abnormalities or other conditions that, at the Investigator's discretion, will make it unsuitable for the patient to participate in this clinical trial.