This is a phase I clinical study. All subjects are patients with advanced solid tumors. The purpose of this study is to to evaluate the safety, tolerability, pharmacokinetic (PK) characteristics, and preliminary antitumor efficacy of HDM2017 in patients with advanced malignant solid tumors.

Inclusion Criteria:

1. Be able and willing to provide written informed consent.
2. Male or female participants aged 18 to 75 years.
3. Participants with histologically or cytologically confirmed locally advanced unresectable or metastatic malignant solid tumors who have failed adequate standard of care, or are intolerant to standard of care, or have no effective standard treatment options.
4. Be able to provide archived tumor tissue during the screening period.
5. Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 or 1.
6. Life expectancy ≥3 months.
7. According to RECIST v1.1, participants must have at least one measurable lesion.
8. Has adequate organ function.
9. All subjects of reproductive potential must agree to use an effective method of contraception, as determined by the Investigator, during and for 7 months after the last dose of study treatment.
10. Be willing and able to complete regular visits, treatment plans, laboratory tests, and other trial procedures.

Exclusion Criteria:

1. Participants who have previously received ADC therapy containing Top I inhibitors, or other drug therapy targeting the CDH17 target.

2. Participants who have received the following treatments:

   1. Participants who have undergone major surgery within 4 weeks before the first dose;
   2. Participants who have received radiotherapy involving the bone marrow or extensive radiotherapy within 4 weeks before the first dose; or local radiotherapy within 2 weeks before the first dose;
   3. Participants receiving continuous systemic corticosteroid therapy;
   4. Participants who have received systemic antitumor therapy, or any other investigational drug therapy within 4 weeks or 5 half-lives (whichever is shorter; at least 2 weeks) before the first dose.

3. Participants with other malignant tumors within the past 5 years, other than the tumor being treated in this study, with the exception of locally cured tumors (such as basal cell carcinoma, cutaneous squamous cell carcinoma, superficial bladder cancer, carcinoma in situ of the cervix or breast).

4. Related AEs from prior therapy (except for alopecia and ≤Grade 2 sensory neuropathy) have not recovered to ≤Grade 1 or baseline level.

5. Known weight loss of >10% within 2 months before the first dose of study drug or other indicators showing severe malnutrition.

6. History of gastrointestinal perforation, abdominal fistula, or extensive intestinal resection within 6 months before the first dose; complete or incomplete gastrointestinal obstruction or intra-abdominal abscess within 3 months before the first dose.

7. History of gastrointestinal hemorrhage within 3 months before the first dose, or a clear gastrointestinal hemorrhagic diathesis.

8. Participants with known active CNS metastasis.

9. Participants with cardiovascular/cerebrovascular disorder, symptoms, or manifestations.

10. Participants with active syphilis, history of human immunodeficiency virus (HIV) infection, active hepatitis B virus (HBV) or active hepatitis C virus (HCV), except for asymptomatic chronic hepatitis B or C virus carriers.