A Phase II Clinical Study to Evaluate the Efficacy and Safety of HLX43 (Anti-PD-L1 ADC) in Patients With Advanced Gynecological Malignant Tumors

1. Volunteer to participate in clinical research; To fully understand and understand this study and to sign the Informed Consent Form (ICF); Willing to follow and able to complete all test procedures;

2. The age of signing ICF is ≥ 18 years old and ≤ 75 years old;

3. Cohort 1: Metastatic or recurrent cervical cancer including squamous cell, adenocarcinoma or adenosquamous histology confirmed by histopathology or cytology.

Cohort 2: Histologically confirmed high-grade serous ovarian, fallopian tube, or primary peritoneal cancer.

4. Cohort 1: Previous failure or progression of standard systemic therapy for cervical cancer (For patients with PD-L1 expression positive \[CPS≥1\], the standard therapy is defined as platinum-based chemotherapy in combination with immune checkpoint inhibitor (ICI) therapy; for patients with PD-L1 expression negative \[CPS\<1\], the standard therapy is defined as platinum-based chemotherapy), or intolerability toxicity (CTCAE≥3 adverse events), or contraindications to standard therapy.

Cohort 2: Ovarian cancer patients with platinum-resistant disease: If the patient has previously received only first-line platinum-based chemotherapy, platinum resistance is defined as having received at least 4 cycles of platinum-based chemotherapy, with the tumor showing a response to platinum-based chemotherapy (best tumor assessment being complete remission/partial remission), and the time from the last platinum-based chemotherapy to tumor progression being \>3 months and ≤6 months. If the patient has previously received multiple lines of platinum-based chemotherapy, platinum resistance is defined as disease progression occurring during the last line of platinum-based chemotherapy treatment or within 6 months after the last platinum-based chemotherapy.

5. Within 4 weeks prior to the first administration of the medication, at least one measurable target lesion must be evaluated according to the RECIST v1.1 criteria;

6. Tumor tissue should be provided as much as possible for an evaluable PD-L1 expression result at Screening period；

7. Before the initial administration of the study drug, there should be at least a 3-week interval or 5 times the half-life of the last cytotoxic chemotherapy, immunotherapy, or biological therapy, whichever is shorter. There should be at least a 2-week interval from the previous small molecule targeted therapy, at least a 1-week interval from traditional Chinese medicine treatment with antitumor indications or minor surgery. Additionally, treatment-related adverse events (AEs) should have recovered to NCI-CTCAE grade ≤ 1 (except for grade 2 peripheral neurotoxicity and alopecia)；

8. The ECOG physical performance score of 0-1 in the week prior to randomization；

9. Expected survival ≥ 3 months；

10. Laboratory tests within the previous week confirm adequate organ function (within 14 days prior to the first dose of medication, without receiving interventions such as blood transfusions or granulocyte colony-stimulating factor)；

11. Female subjects of childbearing potential must agree to use at least one highly effective method of contraception during the trial and for at least 6 months after the last dose of the study drug. Female subjects of childbearing potential must have a negative pregnancy test within 7 days prior to enrollment.

What this study is about