DB-1317A Study of DB-1317 in Selected Advanced/Metastatic Solid Tumors

Key Inclusion Criteria:

1. Male or female adults
2. Unresectable advanced or metastatic selected solid tumors that have relapsed or progressed on or after standard systemic treatments.
3. Only applicable to backfilling participants in Phase 1a and participants in Phase 1b: At least one measurable lesion as assessed by the investigator according to RECIST version 1.1 criteria. Participants with non-measurable disease are allowed for CRPC participants.
4. Has a life expectancy of ≥ 3 months.
5. Has an ECOG PS of 0-1.
6. Has LVEF ≥ 50% within 28 days before enrollment.
7. Is willing to provide pre-existing resected tumor samples or undergo fresh tumor biopsy for the measurement of ADAM9 expression level and other biomarkers if no contra-indication.
8. Male and female participants of reproductive/childbearing potential must agree to use adequate contraceptive methods

Key Exclusion Criteria:

1. Prior treatment with ADAM9 targeted therapy.
2. Prior treatment with antibody-drug conjugate with topoisomerase I inhibitor.
3. Has a medical history of symptomatic congestive heart failure or serious cardiac arrhythmia requiring treatment.
4. Has a medical history of myocardial infarction or unstable angina within 6 months before enrollment.
5. Has any clinically important abnormalities in rhythm, conduction or morphology of resting ECG
6. Has an average of Fredericia's formula-QT corrected interval (QTcF) prolongation to > 470 ms in males and females
7. Has a history of (non-infectious) ILD/pneumonitis
8. Has a lung-specific intercurrent clinically significant illness
9. Has an uncontrolled infection requiring intravenous injection of antibiotics, antivirals, or antifungals.
10. Known human immunodeficiency virus (HIV) infection;Chronic, active, or uncontrolled hepatitis B;
11. Known chronic, active, or uncontrolled hepatitis C
12. Has clinically significant corneal disease.
13. Has clinically active brain metastases
14. Has unresolved toxicities from previous anticancer therapy Concurrent malignancy < 3 years.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.