DEFINITION

Sargramostim is a single-chain, glycosylated polypeptide of 127 amino acid residues expressed from Saccharomyces cerevisiae. The glycoprotein primarily consists of three molecular species having relative molecular weights of approximately 19,500; 16,800; and 15,500 due to different levels of glycosylation. Sargramostim has the property of generating granulocyte, macrophage, and mixed granulocyte macrophage colonies from hematopoietic progenitor cells found in bone marrow. It possesses the primary sequence of the natural form of granulocyte-macrophage colony-stimulating factor with a substitution in the amino acid residue at position 23 (Leu₂₃ in place of Arg₂₃). It has a biological potency of NLT 73.0% and NMT 146.0% of the potency stated on the label, the potency being 5.6 million USP Sargramostim Units/mg of protein. The presence of host cell DNA and host cell protein impurities in Sargramostim is process-specific; the limits of these impurities are determined by validated methods.