A drug that targets a protein known as phosphatidylserine boosted the response rate for hepatocellular carcinoma (HCC) patients receiving immunotherapy without compromising their safety, according to results of a clinical trial. The findings show the potential benefits of augmenting immunotherapy for this and other forms of cancer. Several years ago, researchers discovered that phosphatidylserine, a fatty substance called a phospholipid sometimes present on the surface of cancer cells, appeared to interact with immune cells to prevent them from attacking tumors. An antibody drug called bavituximab that neutralizes phosphatidylserine showed no effect on tumor response, progression, or survival when administered alone...