HS-20089 in Patients With Ovarian Cancer and Endometrial Cancer

Inclusion Criteria:

1. Males or females aged 18 years or older (≥18 years).

2. Patients diagnosed with recurrent or metastatic ovarian cancer, endometrial canceror other solid tumors.

3. Subjects have at least one target lesion as assessed per the RECIST 1.1. Patientswith only brain and/or bone lesions as target lesions are ineligible.

4. Tumor tissue from a newly obtained biopsy (FFPE tumor tissue blocks or slides areacceptable) is required. If the newly obtained biopsy is not feasible, newlyobtained FFPE slides cut from archival tumor tissue blocks within 2 years prior tothe first dose of study drug are acceptable.

5. Eastern Cooperative Oncology Group Performance Status (ECOG PS) score of 0 to 1 andno deterioration within 2 weeks before the first dose.

6. Have a life expectancy of at least 12 weeks.

7. Female subjects of childbearing potential are willing to take appropriatecontraceptive measures and should not breastfeed from signing the informed consentuntil 6 months after the last dose; male subjects must agree to use barriercontraception (i.e. condoms) from signing the informed consent to 6 months after thelast dose.

8. Female subjects must have a negative pregnancy test within 7 days prior to the firstdose (for subjects with tumor related abnormal elevation of human chorionicgonadotropin [HCG], an ultrasound of uterus and appendages should be performedwithin 7 days prior to the first dose to rule out pregnancy), or demonstrate no riskfor pregnancy.

9. Subject must be voluntarily enrolled in this clinical trial, be able to understandthe study procedures and to sign written informed consent.

Exclusion Criteria:

1. Have received or is currently receiving the following treatment:

2. B7-H4-targeted therapies.

3. Have received any of cytotoxic chemotherapy drugs, investigational drugs,anti-tumor traditional Chinese medicines or other anti-tumor drugs (includingendocrine therapy, molecular targeted therapy, biotherapy, etc.) within 14 daysprior to the first dose of study drug; or need to continue these drugs duringthe study.

4. Have received macromolecular antitumor drugs (including immunotherapy, such asmonoclonal antibodies and bispecific antibodies) within 28 days prior to thefirst dose of study drug.

5. Have received locoregional radiation therapy within 2 weeks prior to the firstdose of study drug; more than 30% of bone marrow irradiation or wide-fieldradiation therapy within 4 weeks prior to the first dose of study treatment.

6. Major surgery (such as craniotomy, thoracotomy or laparotomy, etc.) within 4weeks prior to the first dose of study treatment.

7. Use of strong inhibitors or inducers of CYP3A4, CYP2D6, P-gp, or BCRP, orsensitive substrates of CYP3A4, CYP2D6, P-gp, or BCRP with narrow therapeuticwindow within 7 days prior to the first dose of study drug; or in need ofcontinuing treatment with these drugs during the study.

8. Current use of drugs known to prolong the QT interval or potentially causetorsades de pointes; or need to continue these medications during the study.

9. Presence of Grade ≥ 2 toxicities as per Common Terminology Criteria for AdverseEvents (CTCAE version 5.0) due to prior anti-tumor therapy (except alopecia andresidual neurotoxicity).

10. Presence of pleural/abdominal effusion requiring clinical intervention.

11. Known history of prior malignancy.

12. Evidence of brain metastasis, unless meeting all of the following criteria:

13. Asymptomatic; medically stable for at least four weeks prior to the first dose;

14. No steroid treatment required for at least two weeks prior to the first dose;

15. No stereotactic radiation therapy, whole brain radiotherapy, and/orneurosurgical resection within 4 weeks prior to the first dose;

16. No history of intracranial or spinal hemorrhage;

17. Have at least one target lesion other than CNS lesion according to RECIST v1.1;

18. Inadequate bone marrow reserve or hepatic/renal functions.

19. Cardiological examination abnormality.

20. Severe, uncontrolled or active cardiovascular disorders.

21. Serious or poorly controlled diabetes.

22. Serious or poorly controlled hypertension.

23. Clinically significant bleeding symptoms or significant bleeding tendency within 1month prior to the first dose of study treatment.

24. Serious arteriovenous thromboembolic events within 3 months prior to the first doseof study treatment.

25. Serious infections within 4 weeks prior to the first dose.

26. Have received systemic glucocorticoid therapy for more than 30 days within 30 daysprior to the first dose study treatment, or require chronic (≥ 30 days) use ofsystemic glucocorticoids during the study, or have other acquired, congenitalimmunodeficiency disorders, or a history of organ transplantation.

27. Presence of active infectious diseases such as hepatitis B, hepatitis C,tuberculosis, syphilis, or human immunodeficiency virus infection, etc.

28. Current hepatic encephalopathy, hepatorenal syndrome, or Child-Pugh Class B or moresevere cirrhosis.

29. Any moderate or severe lung diseases that may interfere with the detection andtreatment of drug-related pulmonary toxicity or may seriously affect respiratoryfunction.

30. History of severe neurological or psychiatric disorder.

31. Pregnant or breast-feeding women or women who intend to become pregnant during thestudy.

32. Attenuated live vaccination within 4 weeks prior to the first dose.

33. Allergies or hypersensitivity reactions within 4 weeks prior to the first dose.History of severe allergies (e.g., anaphylactic shock), or severe infusion-relatedreactions. Allergy or hypersensitivity to any component of HS-20089.

34. Subjects unlikely to comply with study procedures, restrictions and requirement asdetermined by the investigator.

35. Subjects with any condition that jeopardizes the safety of the patient or interfereswith the assessment of the study, as judged by the investigator.