Europe approved the marketing of IDMPharma’s mifamurtide injection (mifamurtide, L-MTP-PE, :Mepact) for the treatment of non-metastatic resectable osteosarcoma (a rare but predominantly fatal bone tumor in children and young adults). It is the first new drug approved for marketing for the treatment of osteosarcoma in more than 20 years. Mivamutide is the first drug in more than 20 years to improve long-term survival in patients with osteosarcoma. Patients are treated with preoperative chemotherapy, followed by surgery to remove the osteosarcoma, and then chemotherapy. While patients receive post-operative chemotherapy they also receive intravenous injections of mivamutide for immunotherapy (twice a week for 3 months, followed by once a week for 6 months). Studies have shown that mivamutide completely removes residues from the microscopic trenches of the disease. Mivamutide kills tumor cells by stimulating certain white blood cells such as macrophages. It is made into spherical liposomes, and inside the vesicles is cytosolic acyl tripeptide (MTP). This lipid triggers macrophages to consume mevalonate. Once consumed, MTP stimulates macrophages, especially in the liver, spleen and lungs, to seek out and kill tumors. The approval of mivamutide injection is based on the results of a phase III clinical study. A collaborative group established by the National Cancer Institute (NCI) and studied by the Children’s Oncology Group (COG) completed the largest study of this product for the treatment of osteosarcoma in approximately 800 patients enrolled in the study. The study evaluated the results of mivamutide in combination with three to four adjuvant chemotherapeutic agents (cisplatin, doxorubicin, methotrexate, with or without isocyclophosphamide). The study showed that the combination of mivamutide with chemotherapy reduced mortality by about 30% and 78% of treated patients survived up to 6 years or more.