A Clinical Study to Investigate the Safety, Tolerability, Pharmacokinetics, Immunogenicity and Preliminary Efficacy of HF158K1 in Participants With HER-2 Positive or HER-2 Low Expression Advanced Solid Tumors

Inclusion Criteria:

1. Voluntary to participate in the clinical study, sign a written informed consentform, and able to comply with clinical visits and study-related procedures.

2. Male or female participants at least 18 years old when signing the informedconsent form.

3. ECOG performance score of 0 to 1 point. 4. Study population: HER-2 positive (IHC 3+, or IHC 2+ with ISH +) or HER-2 low expression (IHC 2+ with ISH -, orIHC 1+) participants with unresectable or metastatic advanced solid tumors (confirmed by histopathology or cytology analysis) who have failed or areintolerant (disease progression, or intolerance to chemotherapy, targetedtherapy, etc.) to standard treatment, or currently have no available treatmentregimen.

4. Expected survival of at least 3 months. 6. According to the RECIST v1.1criteria, there is at least one measurable lesion in the dose expansion stage.

5. The functional level of bone marrow reserve and organs must meet the followingrequirements (without ongoing continuous supportive treatment): Bone marrowreserve: neutrophil count (NE#) ≥ 1.5×109/L, platelet count (PLT) ≥ 90×109/L,and hemoglobin (HGB) > 9.0 g/dL (no blood transfusion or hematopoieticstimulating factor therapy within 14 days).

Coagulation function: activated partial prothrombin time (APTT) prolonged to ≤1.5×ULN, and international normalized ratio (INR) ≤1.5.

Liver function: total bilirubin (TBIL) ≤ 1.5×ULN, and alanine aminotransferase (ALT), and aspartate aminotransferase (AST) ≤ 2.5×ULN, if there is liver metastasis, ALT and AST ≤ 5×ULN and TBIL≤ 3×ULN.

Renal function: creatinine clearance ≥ 50 mL/min or serum creatinine ≤ 1.5×ULN. 8. Eligible Participants with fertility (male and female) must agree to use reliable contraceptive methods with their partners and have no plan to have baby during the study period and at least 6 months after the last administration. female Participants of childbearing age must have a negative serum or urine pregnancy test during screening period and before the first dose.

9. Other participants that can potentially benefit from the investigational drug asassessed by the investigator.

Exclusion Criteria:

1. Participants who are known to be allergic to doxorubicin and/or other similarcompounds, or to any of excipients of HF158K1, or participants with allergicconstitution (multiple drug and food allergies).

2. Participants who have used doxorubicin prior to screening with a totalcumulative dose > 350 mg/m2 (other anthracyclines converted by 1 mg doxorubicinequivalence: 2 mg epirubicin, or 2 mg epirubicin, or 2 mg zolpidem, or 0.5 mgdemethoxyzolpidem), or who have received anthracyclines and suffered severecardiotoxicity, or who discontinued doxorubicin liposome therapy due to seriousadverse events.

3. Participants who received radiotherapy or chemotherapy (paclitaxel,cyclosporine, dextropropylenol, cytarabine, streptozotocin, etc.) within 4weeks prior to first dose administration, or received other antitumor therapysuch as endocrine therapy, herbal therapy, or local radiation therapy for painrelief within 2 weeks prior to first dose administration, except for thefollowing: Nitrosourea or mitomycin C within 6 weeks prior to the firstadministration of the investigational drug.

Oral fluorouracil-based and small-molecule targeted drugs for 2 weeks prior to the first administration of the investigational drug or within 5 half-lives of the drug (whichever is longer).

4. Participants with brain parenchymal metastases or meningeal metastases with clinicalsymptoms that, in the judgment of the investigator, are not suitable for enrollment (those who have received prior treatment (radiation or surgery) for systemic,radical brain metastases, have maintained imaging- confirmed stability for at least 28 days, and have discontinued systemic steroid therapy for > 14 days withoutclinical symptoms will be allowed for enrollment).

5. Participants who have not recovered to < Grade 1 (according to CTCAE 5.0) or topre-treatment baseline levels from all prior treatment-induced adverse events priorto the first dose (except for adverse events without safety risks as judged by theinvestigator, such as alopecia, Grade 2 peripheral neurotoxicity, and stabilizedhypothyroidism under hormone replacement therapy).

6. Participants who are taking (or are not able to discontinue until at least 1 weekbefore the first dose of the study) any drug known to strongly inhibit or stronglyinduce CYP3A4, CYP2D6 or P-gp.

7. Participants with a history of serious cardiovascular and cerebrovascular diseases,including but not limited to: Serious heart rhythm or conduction abnormalities, suchas ventricular arrhythmia that requires clinical intervention, degree II-IIIatrioventricular block, etc.

Cardiac function: left ventricular ejection fraction (LVEF) ≤ 50%, corrected QT interval (QTcF) > 470 ms.

Thromboembolic events requiring therapeutic anticoagulation within 3 months before the first administration, or participants with venous filters.

Participants with Class III~IV cardiac insufficiency according to the New York Heart Association (NYHA) criteria.

Acute coronary syndrome, congestive heart failure, aortic dissection, stroke or other Grade 3 and above cardiovascular and cerebrovascular events within 6 months before the first administration.

Clinically uncontrollable hypertension (systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg), and patients with a history of hypertension were allowed to enroll as long as their blood pressure was controlled below this limitation through antihypertensive therapy.

Any factors that increase the risk of QTc prolongation or arrhythmia, such as heart failure, hypokalemia, congenital long QT syndrome, or use of any concomitant drug that are known to or may prolong the QT interval.

8. Participants who have received last dose of any other investigational drug productor treatments within 28 days prior to the first administration of theinvestigational drug.

9. Participants who have undergone major organ surgery (excluding needlebiopsy，tracheotomy, gastrostomy, etc.) or had significant trauma within 28 daysbefore the first administration of investigational drug or need to undergo electivesurgery during the study period.

10. Participants with a serious unhealable wound/ulcer/fracture within 28 days beforethe first administration of the investigational drug.

11. Participants with an active infection within 1 week prior to the firstadministration of the investigational drug and currently require intravenousanti-infection therapy.

12. Third space effusion that cannot be clinically controlled and is not suitable forenrollment as judged by the investigator.

13. Known history of drug abuse. 14. Participants with mental disorders or poorcompliance. 15. HIV infection, active HBV infection (HBV DNA > ULN), or active HCVinfection (HCV RNA > ULN).

14. Women who are pregnant or breastfeeding. 17. Participants who cannot tolerate venousblood sampling. 18. The investigator believes that the participant has a history ofother serious systemic diseases or is not suitable for participating in thisclinical study for other reasons.