A Study of BL-M17D1 in Patients With Locally Advanced or Metastatic HER2 Positive/Lower Expression Gastrointestinal Cancer and Other Solid Tumors

Inclusion criteria

• Voluntarily sign the informed consent and follow the requirements of the protocol;
• No gender limit;
• Age: ≥18 years old and ≤75 years old (stage Ia); ≥18 years old (stage Ib);
• Expected survival time ≥3 months;
• The pathologic histology and/or cytology diagnosis of locally advanced or metastatic positive HER2 / low expression of the digestive tract tumor and other solid tumor;
• Consent to provide archival tumor tissue samples or fresh tissue samples from primary or metastatic lesions within 2 years;
• Must have at least one measurable lesion according to RECIST v1.1 definition;
• ECOG 0 or 1;
• Toxicity of previous antineoplastic therapy has returned to ≤ grade 1 defined by NCI-CTCAE v5.0;
• No severe cardiac dysfunction, left ventricular ejection fraction ≥50%;
• Organ function level must meet the requirements;
• Coagulation function: international normalized ratio ≤1.5, and activated partial thromboplastin time ≤1.5ULN;
• Urine protein ≤2+ or ≤1000mg/24h;
• For premenopausal women with childbearing potential, a pregnancy test must be performed within 7 days before the initiation of treatment, serum pregnancy must be negative, and must be non-lactating; All the patients (no matter male or female) shall be 6 months after the end of the treatment period and full barrier precautions.

Exclusion criteria

• Anti-tumor therapy such as chemotherapy or biological therapy has been used within 4 weeks or 5 half-lives before the first dose; Mitomycin and nitrosoureas were administered within 6 weeks before the first dose; Oral drugs such as fluorouracil;
• History of severe heart disease;
• QT prolongation, complete left bundle branch block, III degree atrioventricular block, frequent and uncontrollable arrhythmia;
• Active autoimmune and inflammatory diseases;
• Other malignant tumors diagnosed within 5 years before the first dose;
• Hypertension poorly controlled by two antihypertensive drugs;
• Patients with poor glycemic control before the first dose;
• Have to hormone treatment of interstitial lung disease, or the current with ILD or suspected suffering from such diseases;
• Complicated pulmonary diseases leading to clinically severe respiratory function impairment;
• Patients with massive or symptomatic effusions or poorly controlled effusions;
• Imaging examination showed that the tumor had invaded or wrapped around the chest, neck, pharynx and other large blood vessels;
• Screening for unstable thrombotic events requiring therapeutic intervention within the preceding 6 months;
• Patients with active central nervous system metastases;
• Patients with a history of allergy to recombinant humanized antibody or human-mouse chimeric antibody or to any of the excipients of BL-M17D1;
• Prior organ transplantation or allogeneic hematopoietic stem cell transplantation;
• HIV antibody positive, active tuberculosis, active hepatitis B virus infection, or active hepatitis C virus infection;
• Active infection requiring systemic therapy with serious infection within 4 weeks before informed consent; There were indications of pulmonary infection or active pulmonary inflammation within 2 weeks before informed consent;
• Participated in another clinical trial within 4 weeks before the first dose;
• Pregnant or lactating women;
• Patients with superior vena cava syndrome should not be rehydrated;
• A history of severe neurological or psychiatric illness;
• Severe unhealed wound, ulcer, or fracture within 4 weeks before signing the informed consent;
• Subjects with clinically significant bleeding or obvious bleeding tendency within 4 weeks before signing the informed consent;
• History of intestinal obstruction, inflammatory bowel disease, or extensive bowel resection or presence of Crohn's disease, ulcerative colitis, or chronic disease Sexual diarrhea;
• Patients scheduled for vaccination or receiving live vaccine within 28 days before the first dose;
• Other conditions for participation in the trial were not considered appropriate by the investigator.