A Phase I Study to Investigate the Safety and Tolerability of KGX101 Monotherapy and Combination Therapy With Envafolimab in Advanced or Metastatic Solid Tumor Patients

This is a phase I, open-label, multi-center, dose escalation and expansion study in advanced or metastatic solid tumor patients. The're are two goals set in this study: one is to explore the safety and tolerability of KGX101 when mono and combo with envafolimab in Chinese patients, the other is to determine recommended phase 2 dose of KGX101 mono and combo with envafolimab. Participants will: 1. Take drug KGX101 mono or combo with envafolimab every 3 weeks; 2. Visit the clinic for checkups and tests. Schedule will be about 6-8 times in the first month and then about every 3 weeks afterwards.

Inclusion Criteria: 1. Any histologically or cytologically confirmed solid tumor malignancy that is locally advanced or metastatic and has failed standard of care, no further standard can be used, or standard of care is not fit; 2. Eastern cooperative oncology grous performance status of 0-1; 3. Has at least 1 measurable lesion per RECIST 1.1; 4. Has adequate organ and bone marrow function as per study which including hemoglobin \> 90 g/L, platelet count \>=100\*10e9/L, absolute meutrophil count \>=1.5\*10e9/L; 5. Life expectancy of at least 3 months; 6. Provision of signed and dated written inform consent prior to any study-related procedures, sampling and analyses. Exclusion Criteria: 1. Active known second malignancy except adequately treated basal cell carcinoma, squamous cell skin cancer, in situ cervical cancer, breast cancer; 2. Patients with primary CNS malignancies; 3. Evidence of severe or uncontrolled systemic diseases, including: active infection, hypertension, chronically unhealed wound or ulcers; 4. Active autoimmnue disease requiring systemic treatment in the last 2 years, or immunodefiency which is on immunosuppressive therapy, chronic systemic or enteric steroid therapy; 5. History of pneumonitis, interstitial lung disease which require steroids or has current pneumonitis/ interstitial lung disease; 6. Any unresolved toxicities from prior therapy greater than CTCAE 5.0 grade 1.