The main purpose of this study is to investigate the effect of veliparib in ovarian cancer patients with known BRCA 1/2 mutations who do no longer respond to conventional chemotherapy.

The side effects are modest, since PARP inhibitors affect cancer cells to a much larger extent than normal cells. The effect of this PARP-inhibiting treatment is evident although the greatest effect is seen in patients with mutations in BRCA genes. The reason for this is that BRCA deficient cancer cells are unable to repair both DNA double strand and single strand breaks and undergo apoptosis to a large extent.

Inclusion Criteria:

1. Histologically confirmed epithelial, primary fallopian or primary peritoneal cancer. Stages I-IV.

2. Patients with known germline BRCA1/2 mutations

3. Verified progression by either RECIST criteria and/or GCIG CA125 criteria after previous first line chemotherapy or progression after later lines of cytotoxic treatment.

4. Platinum resistance or partially platinum sensitive disease (Relapsed within six months of prior first line/later lines of platinum-based therapy or relapsed within six to twelve months of prior first line/later lines of platinum-based therapy)

5. Age ≥ 18 years.

6. Performance status 0-2.

7. Measurable disease by RECIST 1.1 or evaluable by CA125 GCIG criteria

8. Adequate bone marrow function, liver function, renal function and coagulation parameters (within 7 days prior to randomization):

   WBC ≥ 3.0 x 10^9/l or neutrophils (ANC) ≥ 1.5 x 10^9/l Platelet count ≥ 100 x 10^9/l Hemoglobin ≥ 9.7 g/dl (6 mmol/L) Serum bilirubin ≤ 1.5 x ULN Serum transaminases ≤ 2.5 x ULN Serum creatinine ≤ 1.5 x ULN

9. Written informed consent.

10. Tissue available for BRCAness analysis.

Exclusion Criteria:

1. Previous treatment with a PARP inhibitor.

2. Platinum-refractory disease (disease that progressed or was stable during prior platinum therapy)

3. Patients who have received (or are planning to receive) treatment with any other investigational regimen, or who have participated in another clinical trial within 28 days prior to entering this trial.

4. Pregnant or breast-feeding patients. For fertile women a negative pregnancy test at screening is mandatory.

5. Fertile patients not willing to use acceptable and safe methods of contraception during and for 6 months after treatment

6. Other present or previous malignancy except curatively treated cervical cancer stage I, non-melanotic skin cancer or other cancer with minimal risk of relapse.

   Curatively treated prior breast cancer is allowed if no relapse is suspected at time of inclusion.

7. CNS metastasis.

8. History of any chronic medical or psychiatric condition or laboratory abnormality that is not medically controlled or in the opinion of the Investigator may increase the risks associated with study drug administration. (e.g. diabetes, cardiac diseases, hypertension, renal or liver disease).

9. Allergy to the ingredients of the study medication.