 12. Women of child-bearing potential i.e., women who are pre-menopausal or not surgically sterile must be willing to use an acceptable contraceptive method abstinence, oral contraceptive or double barrier method for the duration of the study and for 5 months following the last dose of nivolumab and 30 days following the last dose of chemotherapy on this trial on this trial, and must have a negative urine or serum pregnancy test within 2 weeks prior to beginning treatment on this trial. If a female subject or female partner of a male subject becomes pregnant during this period then patient will be recommended to seek appropriate obstetric care. The study will not be monitoring subjects or female partners of subjects for pregnancy after the last dose of study drug or chemotherapy. 