My stepmom has stage IV lung cancer with mets to the liver. It had also metastasized to the bone but was surgically removed in October 2014. She is asymptomatic with a performance status of 0-1. She had 1st line treatment with Alimta for just over a year and recently finished four rounds of second line treatment with Keytruda. Any idea what the 3rd line of treatment might be? Apparently there are no clinical trials available.