The purpose of the study was to evaluate the safety and tolerability of BR790 tablets as an oral monotherapy in subjects with advanced solid tumors, and to determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and/or recommended phase II clinical trial dose (RP2D) .The study is divided into two phases: dose escalation phase and dose expansion phase.

Inclusion Criteria:

• Sign informed consent voluntarily.
• Age ≥18 and ≤75 years old.
• Subjects with advanced solid tumors diagnosed by histology or cytology，whose desease progressed after standard treatment or have no standard treatment.
• Had at least one measurable lesion.
• ECOG≤1.
• Expected survival period ≥ 3 months.

Exclusion Criteria:

• Any previous treatment with SHP-2 inhibitor.
• Symptomatic brain metastases.
• Subjects with thoracic/ascites fluid that need drainage or intervention.
• Subjects with not enough organ functional reserve at baseline, which met at least one of the following criteria： ANC<1.5×10^9/L PLT<100×10^9/L Hb<90g/L TBIL>1.5×ULN ALT, AST>2.5×ULN (without liver metastases) or ALT, AST>5×ULN (with liver metastases), Cr >1.5×ULN.
• With uncontrolled severe disease.