hf50 in her-2 positive and low-expression advanced solid tumors

Conditions: Advanced Solid Tumors

Summary: this is an open-label, single-arm, non-randomized, single-center, dose-escalation study designed to evaluate the safety and tolerability of hf50 in patients with her-2 positive and her-2 low-expression advanced solid tumors. the primary objectives are to assess the safety, tolerability, and determine the maximum tolerated dose (mtd) and/or recommended phase ii dose (rp2d) of hf50. secondary objectives include evaluating the pharmacokinetic (pk) profile and preliminary antitumor activity of hf50.


Eligibility criteria:
inclusion criteria: * participants must voluntarily provide written informed consent (icf) prior to any study-related procedures, and be capable of complying with all protocol requirements. * adult participants aged between 18 and 75 years (inclusive) at the time of icf signing. * histologically or cytologically confirmed advanced her-2 positive or her-2 low-expression solid tumors that are unresectable, metastatic, or have relapsed after standard therapies, are intolerant to standard therapies (e.g., chemotherapy, targeted therapy), or lack effective treatment options. * eastern cooperative oncology group (ecog) performance status of 0 or 1. * life expectancy of at least 3 months. * at least one measurable lesion as defined by recist version 1.1. * adequate organ and bone marrow function as demonstrated by the following laboratory parameters:hematologic function:absolute neutrophil count (anc) ≥1.5×10⁹/l、lymphocyte count ≥1.0×10⁹/l、platelet count ≥90×10⁹/l、hemoglobin ≥9.0 g/dl (without transfusion or erythropoietin-stimulating agents within 14 days)； coagulation parameters:activated partial thromboplastin time (aptt) ≤1.5×uln、 international normalized ratio (inr) ≤1.5. hepatic function:total bilirubin (tbil) ≤1.5×uln、alanine aminotransferase (alt) and aspartate aminotransferase (ast) ≤2.5×uln (≤5×uln for participants with liver metastases, and tbil ≤3×uln)； renal function:creatinine clearance (crcl) ≥50 ml/min (cockcroft-gault formula). * female participants of childbearing potential must have a negative serum pregnancy test at screening and prior to the first dose. male and female participants of childbearing potential must agree to use effective contraception during the study and for 6 months after the last dose. exclusion criteria: * history of active autoimmune disease or autoimmune disease considered unsuitable for study participation, with exceptions for localized skin conditions (e.g., eczema involving \<10% of body surface area, vitiligo, psoriasis, alopecia) or childhood asthma resolved without treatment in adulthood. * current use of immunosuppressants or systemic corticosteroids (\>10 mg/day prednisone or equivalent) within 4 weeks prior to the first dose, except for local steroid use. * receipt of systemic chemotherapy, radiotherapy, targeted therapy, or immunotherapy less than 2 weeks (or 4 weeks for nitrosourea or mitomycin c) or within 5 half-lives of the prior therapy before the first dose. * symptomatic brain metastases or leptomeningeal disease unless adequately treated (e.g., surgery or radiotherapy) with no evidence of progression for ≥28 days and off systemic steroids for ≥14 days prior to the first dose. * unresolved toxicities from prior therapies ≥grade 2 (ctcae v5.0) at baseline, except for toxicities deemed by the investigator to pose no safety risk (e.g., alopecia, stable hypothyroidism with hormone replacement). * significant cardiovascular or cerebrovascular conditions, including but not limited to:thromboembolic events requiring therapeutic anticoagulation within 3 months prior to the first dose.nyha class iii or iv heart failure.acute coronary syndrome, congestive heart failure, aortic dissection, or stroke within 6 months prior to the first dose.uncontrolled hypertension (systolic blood pressure \>160 mmhg or diastolic blood pressure \>100 mmhg), unless controlled with antihypertensive medication. * active infection or unexplained fever \>38.5°c within 1 week prior to the first dose (tumor-related fever may be eligible at the investigator's discretion). * known hiv infection, active hepatitis b virus (hbv) infection (hbv dna \>uln), or active hepatitis c virus (hcv) infection (hcv rna \>uln). * gastrointestinal symptoms or other conditions requiring intervention within 4 weeks prior to the first dose that would, in the investigator's judgment, impair study participation. * pregnant or breastfeeding women. * any other severe systemic disease, psychological condition, or significant clinical abnormality deemed unsuitable for study participation by the investigator.