A Multi-Regional, Open-Label, Dose Escalation and Dose Expansion Phase I 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

• HF158K1 is a HER2-targeting antibody liposome

• How much of the study drug can be given with an acceptable level of side effects
• The effects of the study drug (good and bad)
• How much of the study drug is absorbed into the blood and how fast it is removed
• If research tests can be used in the future to predict who will benefit from HF158K1
• How the study drug is acting on your body

In this study, research participants, once confirmed as eligible to take part, will be assigned to receive the study drug.

This is a dose escalation study. Dose escalation means that the amount of the study drug given will be increased in each group of research participants, to find the most appropriate dose for further study. The dose of the study drug you receive will be determined based on your height and weight. There will be 6 groups based on different doses.

Each dose group has at least 1 participant and the maximum number of participants is decided based on the study progress.

If you are in a lower dose group, you may be allowed to move to a higher dose level if your study doctor determines it is safe.

The study regimen will be given in cycles. Each cycle is 3 weeks long. You will receive the study drug on the first day of each cycle as an intravenous (IV, meaning directly into a vein) infusion over a period of 90 minutes.