A Clinical Study to Evaluate the Efficacy and Safety of JS212 Monotherapy or Combination Therapy in Recurrent or Metastatic Triple-negative Breast Cancer(TNBC)

Prior treatment

• Active autoimmune diseases requiring systemic treatmen within 2 years prior to the first dose;
• History of interstitial lung disease or previous Noninfectious pneumonitis treated with corticosteroids, or evidence of active Pneumonia in radiology on screening period;
• Serious infection (CTCAE 6.0 Grade\>2) within 28 days prior to the first dose of study drug;

Other illness

• Tumor encasement of important vessels or significant necrosis and cavitation that may cause a risk of hemorrhage;
• History of significant bleeding tendency or severe coagulation disorder;
• Uncontrolled hypertension;
• History of immunodeficiency. Presence of active tuberculosis, hepatitis B, or hepatitis C;
• Severe cardiovascular disease;
• History of another malignancy within 5 years before the first dose of study drug;
• Not suitable to receive study treatment for other conditions as per investigator;

Lab values

• Previous treatment of any anti-VRGF drugs targeting VEGF (part 1) or ADC drugs targeting EGFR and/or HER3;

Other

• Untreated or active central nervous system (CNS) metastases;
• Uncontrolled pleural effusion, pericardial effusion or ascites;

• Male or female age 18-70 years old;
• Voluntary participation in clinical study;
• Histologically confirmed unresectable, locally advanced or metastatic triple-negative breast cancer(absence of HER2, ER, and PR expression);
• No prior systemic antitumor therapy for locally advanced or Metastatic TNBC（cohort expansion period); only one line of prior systemetic treatment for locally advanced or metastatic TNBC;
• Adequate organ function;
• ECOG performance status of 0 or 1;
• Life expectancy 12 weeks;
• Measurable disease, as defined by RECIST v1.1;