NCT03602859

Who might be able to join this trial:

• You must be a woman aged 18 or older who can understand the study and agrees to take part by signing a consent form.
• You must have a confirmed diagnosis of a specific type of high-grade ovarian, fallopian tube, or peritoneal cancer (including serous, endometrioid, clear cell, carcinosarcoma, or mixed types) that is at Stage III or Stage IV.
• If you have Stage IV cancer, you may be eligible regardless of whether surgery is planned, has been done, or is not possible.
• If you have Stage III cancer, you may be eligible if you meet certain additional criteria set out by the trial (confirm with trial site).
• You must be willing to provide a blood sample for a specific genetic test related to DNA repair.
• You must be willing to provide at least one tissue sample (from a previous biopsy or surgery) for additional testing.
• If you could become pregnant, you must have a negative pregnancy test within 3 days before starting treatment.
• You must be postmenopausal, surgically unable to have children, or willing to use highly effective contraception — or agree to abstain from activities that could lead to pregnancy — during the study and for 180 days after the last dose.
• Your blood counts, kidney function, and liver function must be at acceptable levels as measured by standard blood tests (confirm with trial site for specific values).
• You must have a good general level of physical functioning, rated 0 or 1 on a standard medical scale (meaning you are fully active or have only minor limitations).
• Your blood pressure must be normal or well controlled with medication (no higher than 140/90 mmHg).
• You must be willing to complete quality-of-life questionnaires throughout the study.
• You must be able to swallow and take oral (by mouth) medication.

Who may not be able to join:

• You have a type of ovarian cancer classified as mucinous, germ cell, transitional cell, or undifferentiated.
• You have low-grade or Grade 1 ovarian cancer.
• You have not fully recovered from a recent major operation.
• You are pregnant, planning to become pregnant during the study or within 180 days after the last dose, or are breastfeeding (or plan to breastfeed within 30 days of the final dose).
• You have active cancer that has spread to the brain or the lining around the brain.
• You have a significant heart or blood vessel condition (confirm with trial site).
• You have a bowel blockage, certain intestinal conditions, a hole in the bowel, or an infection inside the abdomen.
• You have a history of or currently have a blood disorder called myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML).
• You have been treated for another invasive cancer within the last 5 years, received certain chemotherapy or targeted treatments within the last 3 years, or finished hormone therapy within the last 4 weeks (some non-invasive or minor skin cancers may be exceptions — confirm with trial site).
• You are at higher risk of serious bleeding due to recent major injury, major surgery in the last 28 days, or a history of stroke or significant bleeding in the last 3 months.
• Your immune system is significantly weakened for any reason.
• You have active hepatitis B or hepatitis C infection.
• You have a serious uncontrolled medical condition, non-cancer illness, or uncontrolled infection that puts you at high medical risk.
• You have taken part in another clinical trial and received an experimental treatment within the past 4 weeks (or longer, depending on the treatment).
• You have received a live vaccine within 14 days before starting the study (non-live flu vaccines are generally allowed).
• You have a known allergy or serious sensitivity to any of the study drugs: paclitaxel, carboplatin, niraparib, bevacizumab, or dostarlimab.
• You have already received treatment (such as chemotherapy, immunotherapy, or radiation) specifically for this high-grade ovarian, fallopian tube, or peritoneal cancer.
• You have an active autoimmune disease that has needed systemic (whole-body) medical treatment in the past 2 years (routine hormone replacements like thyroid medication or insulin are not considered systemic treatment).
• You