Efficacy and Safety of BG-C9074 With Bevacizumab Compared With Bevacizumab in Adults With Ovarian, Fallopian Tube, or Primary Peritoneal Cancers

Ovarian cancer is a disease where abnormal cells in the ovaries or fallopian tubes grow out of control and form tumors. Common early signs include belly bloating, pelvic or back pain, feeling full quickly when eating, and frequent urination.

BG-C9074 is a targeted cancer medicine called an antibody-drug conjugate (ADC). ADC consists of an antibody linked to a drug that can kill cancer cells. The antibody part of BG-C9074 specifically attaches to a protein called B7-H4 that is found on the surface of cancer cells. After it attaches to B7-H4, BG-C9074 enters the cancer cell where the drug causes DNA damage and cell death. Bevacizumab is an approved medicine used to treat these cancers along with chemotherapy. It works by cutting off the blood supply that helps the tumor grow, which may help keep the cancer under better control.

The purpose of this study is to test if BG-C9074 is safe and effective in women with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer when it is given in combination with bevacizumab as a first-line maintenance treatment.

This study has 2 treatment groups. Participants will be randomly assigned (by chance, like flipping a coin) to receive one of the treatments listed below:

* Arm A: BG-C9074 + Bevacizumab
* Arm B: Bevacizumab

This study will enroll approximately 600 participants. The overall time to participate in this study may be up to 5 years. Participants will make regular visits to the clinic for treatment, health checks, blood tests, and for tumor and imaging tests.

• BG-C9074 (Drug): Administered by Intravenous infusion
• Bevacizumab (Drug): Administered by Intravenous infusion

Primary outcomes

• Progression-Free survival (PFS) assessed by Blinded Independent Central Review (BICR) [Up to 5 years]: PFS is defined as the time from randomization to the date of disease progression by BICR based on Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 or death, whichever occurs first.

Secondary outcomes

• Overall Survival (OS) [Up to 5 years]: OS is defined as the time from randomization to death due to any reason.
• PFS, as Assessed by Investigator [Up to 5 years]: PFS is defined as time from randomization to the date of disease progression by Investigator based on RECIST v1.1 or death, whichever occurs first.
• PFS2, as Assessed by Investigator [Up to 5 years]: PFS2, as assessed by investigator, is defined as time from randomization to the documented disease progression on first subsequent systemic therapy by Investigator or death due to any cause, whichever occurs first.
• Time to Next Treatment [Up to 5 years]: Time to next treatment is defined as the time from randomization to the start of the first subsequent anticancer therapy after discontinuation of randomized treatment, or death due to any cause.
• Number of Participants with Treatment-Emergent Adverse Events, Treatment-Related Adverse Events, and Serious Adverse Events [From first dose of study drug up to 30 days after last dose, up to 24 months]: An adverse event is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study treatment, whether considered related to study treatment or not. A serious adverse event is any untoward medical occurrence that, at any dose, meets one or more of the criteria listed in the view of either the investigator or the Sponsor: 1. Results in death 2. Is life-threatening 3. Requires inpatient hospitalization or prolongation of existing hospitalization 4. Results in persistent or significant disability/incapacity 5. Is a congenital anomaly/birth defect
• Change from Baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) - F17 Global Health Status/Quality of Life (GHS/QoL), Role Functioning, and Physical Functioning Domain Scores [Baseline and up to approximately 2 years]: The EORTC QLQ-F17 is a 17-item questionnaire that covers GHS/QoL and five functional scales (Physical, Role, Emotional, Cognitive, and Social). All items are scored on a 4-point - Likert scale (1 = "Not at all"; 4 = "Very much"), except the two items of the GHS/QoL-scale that are scored on a 7-point scale (1 = "Very poor"; 7 = "Excellent"). Scores are averaged and transformed to a 0 to 100 scale. Higher scores in GHS/QoL and functional scales indicate better health-related quality of life (HRQoL).
• Change from Baseline in EORTC QLQ -Ovarian Cancer Module (OV28) Abdominal/GI Symptoms Domain Score [Baseline and up to approximately 2 years]: The EORTC QLQ-OV28 includes a 28-item questionnaire for evaluating ovarian cancer-specific symptoms and concerns in participants of cancer clinical studies. These include items that assess symptoms in the abdominal/gastrointestinal domain. Scores are averaged and transformed to a 0 to 100 scale; higher scores indicate a greater symptom burden, while lower scores reflect fewer symptoms.
• Time to Deterioration (TTD) of GHS/QoL, Role Functioning, and Physical Functioning Domain Scores as Measured via EORTC QLQ - F17 [Up to 5 years]: TTD of GHS/QoL is defined as the time from the date of randomization to the first confirmed clinically meaningful deterioration on the abdominal/gastrointestinal symptom domain of the EORTC QLQ-F17.
• Time to deterioration (TTD) of Abdominal/GI Symptoms as Measured via EORTC QLQ - OV28 [Up to 5 years]: TTD of Abdominal/GI Symptoms is defined as the time from the date of randomization to the first confirmed clinically meaningful deterioration on the abdominal/gastrointestinal symptom domain of the EORTC QLQ-OV28.

Sex: Female, ages: 18 Years to any

Inclusion Criteria:

1. Able to provide a signed and dated written informed consent prior to any study-specific procedures, sampling, or data collection.
2. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1.
3. Participants must have a histologically confirmed diagnosis of epithelial high-grade ovarian, fallopian tube or primary peritoneal carcinoma (serous, endometrioid, or clear cell).
4. Participants are newly diagnosed International Federation of Gynecology and Obstetrics (FIGO) stage III or IV and have received primary debulking surgery or interval debulking surgery.
5. Participants must have adequate organ function.
6. Women of childbearing potential must be willing to use a highly effective method of birth control and agree not to donate eggs (ova, oocytes) or freeze/store eggs for the duration of the study and for ≥ 7 months after the last dose of study treatment.

Exclusion Criteria:

1. Participants have ovarian, fallopian tube, or peritoneal cancer of nonepithelial origin.
2. Participants have either a germline or somatic BReast CAncer gene (BRCA) mutation as per local test.
3. Participants who will receive poly-adenosine diphosphate ribose polymerase (PARP) inhibitor as maintenance therapy per standard of care and investigator discretion.
4. Participants have a history of allergic reactions or hypersensitivity to the active ingredients and excipients of the drug products and other monoclonal antibodies.
5. Participants had previous transient ischemic attack, cerebrovascular accident, or subarachnoid hemorrhage within 6 months prior to randomization
6. Participants have evidence of bleeding diathesis or significant coagulopathy (in the absence of anticoagulation therapy).

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

• Study Director, Study director, BeOne Medicines