A Study of Niraparib (GSK3985771) Maintenance Treatment in Participants With Advanced Ovarian Cancer Following Response on Front-Line Platinum-Based Chemotherapy
Condition: Ovarian Neoplasms
MeSH terms: Ovarian Neoplasms; Carcinoma, Ovarian Epithelial
Intervention: Niraparib; Placebo
Intervention description: Niraparib will be administered.; Placebo will be administered.
Intervention MeSH terms: Niraparib
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 733.0
Sex: Female
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Ovarian Cancer; Niraparib; GSK3985771; Poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP)Inhibitor; Homologous recombination deficiency (HRD); HRD positive; PRIMA; PRIMA Clinical Trial; PRIMA Study

Summary:

      This study aims to assess efficacy of Niraparib (GSK3985771) as maintenance treatment in
      participants with Stage III or IV ovarian cancer. Participants must have completed front-line
      platinum based regimen with complete response (CR) or partial response (PR). Data collection
      for Secondary Outcome measures is ongoing and the approximate duration of the study will be 7
      years.
    

Eligibility criteria:

        Inclusion criteria:

          -  Participants must have histologically diagnosed high-grade serous or endometrioid, or
             high-grade predominantly serous or endometrioid ovarian cancer, fallopian tube cancer,
             or primary peritoneal cancer that is Stage III or IV according to Federation
             Internationale de Gynécologie et d'Obstétrique (FIGO) criteria.

          -  Participants with inoperable Stage III and IV disease; All Stage IV participants with
             operable disease; Participants with stage III or IV disease treated with neoadjuvant
             chemotherapy and interval debulking surgery; and Participants with stage III disease
             who have visible residual disease after primary debulking surgery.

          -  Participants who have received intraperitoneal chemotherapy; All participants must
             have had more than or equal to (>=)6 and less than or equal to (<=)9 cycles of
             platinum-based therapy; Participants must have had >=2 post-operative cycles of
             platinum-based therapy following interval debulking surgery; Participants must have
             physician assessed Complete response (CR) or Partial response (PR) after >=3 cycles of
             therapy; and Participants must have either Cancer antigen 125 (CA-125) in the normal
             range or CA-125 decrease by more than 90 percent(%) during their front-line therapy
             that is stable for at least 7 days (no increase more than (>)15% from nadir).

          -  Participants must be randomized within 12 weeks of the first day of the last cycle of
             chemotherapy.

          -  All participants must agree to undergo central tumor HRD testing.

          -  Participants of childbearing potential must have a negative serum or urine pregnancy
             test (beta human chorionic gonadotropin [hCG]) within 7 days prior to receiving the
             first dose of study treatment.

        Exclusion criteria:

          -  Participant has mucinous or clear cell subtypes of epithelial ovarian cancer,
             carcinosarcoma or undifferentiated ovarian cancer.

          -  Participants with Stage III disease who have had complete cytoreduction (no visible
             residual disease) after primary debulking surgery.

          -  Participant has undergone more than two debulking surgeries for the study disease.

          -  Participant is pregnant, breastfeeding, or expecting to conceive children while
             receiving study treatment and for up to 180 days after the last dose of study
             treatment.

          -  Participant has a known hypersensitivity to the components of niraparib or its
             excipients.

          -  Participant has received prior treatment with a known PARP inhibitor or has
             participated in a study where any treatment arm included administration of a known
             PARP inhibitor.

          -  Participant is to receive bevacizumab as maintenance treatment.

          -  Participant has had investigational therapy administered within 4 weeks, or within a
             time interval less than at least 5 half-lives of the investigational agent, whichever
             is longer, prior to the first scheduled day of dosing in this study.

          -  Participant has had any known >=Grade 3 anemia, neutropenia or thrombocytopenia due to
             prior chemotherapy that persisted >4 weeks.

          -  Participant has a condition (such as transfusion dependent anemia or
             thrombocytopenia), therapy, or laboratory abnormality that might confound the study
             results or interfere with the participation for the full duration of the study
             treatment, including:

               1. Participant received a transfusion (platelets or red blood cells) within 2 weeks
                  of the first dose of study treatment.

               2. Participant received colony-stimulating factors (e.g., granulocyte colony
                  stimulating factor [G-CSF], granulocyte macrophage colony-stimulating factor
                  [GM-CSF] or recombinant erythropoietin) within 2 weeks prior to the first dose of
                  study treatment.

          -  Participant has been diagnosed and/or treated for invasive cancer less than 5 years
             prior to study enrollment.