Nearly $3 billion a year is wasted on cancer drugs because of the way they are packaged, according to a study in BMJ. These expensive drugs that are injected or infused come in fixed size vials and patients often require less drug than what is sold as a single dose. Because of restrictions on the ability to use leftover drug, the result is that it is usually thrown out. Nevertheless, drugmakers have little incentive to do things differently because the waste enhances their profitability. We spoke to Leonard Saltz, an oncologist with Sloan Kettering Memorial Cancer Center and coauthor of the study, about the findings, why Europe doesn’t have the same problem, and what can be done to stop the waste.