A DOSE FREQUENCY OPTIMIZATION,TRIAL OF NIVOLUMAB 240 MG EVERY 2 WEEKS VS NIVOLUMAB 480 MG EVERY 4 WEEKS IN SUBJECTS WITH ADVANCED OR METASTATIC NON-SMALL CELL LUNG CANCER WHO RECEIVED UP TO 12 MONTHS OF NIVOLUMAB AT 3 MG/KG OR 240 MG EVERY 2 WEEKS: