Shortage of injectable sargramostim

The American Society of Health-System Pharmacists reports a shortage of injectable sargramostim. This drug shortage affects people whose white blood cells have been reduced during cancer chemotherapy, or eliminated entirely during a bone marrow transplant. There is a human protein that stimulates the production of white blood cells, and sargramostim is a synthetic version. As a class these drugs are known as immunostimulators, in this case a granulocyte-macrophage colony stimulating factor (GM-CSF). The brand name of the drug is Leukine, and Genzyme does not give a reason for the shortage. It is easy to speculate that the shortage is related to the fact that Sanofi-Aventis will acquire the drug from Genzyme effective July 1, 2012. The Chemocare website has a more complete description of this drug.