10. Women of childbearing potential (WOCBP) must be using an adequate method of contraception (Pearl-Index < 1) to avoid pregnancy for up to 12 weeks (for ipilimumab therapy) or for 5 months (for nivolumab therapy) after the last dose of investigational product, in such a manner that the risk of pregnancy is minimized. WOCBP include any female who has experienced menarche and who has not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or is not post-menopausal. WOCBP must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of HCG) within 72 hours before the start of ipilimumab or nivolumab.