Mifamurtide (liposomal muramyl tripeptide phosphatidyl
ethanolamine;
Mepact) is an
immunomodulator with antitumor effects that appear to be mediated via activation of monocytes and macrophages. In the EU,
mifamurtide is indicated in children, adolescents, and young adults for the treatment of high-grade, resectable, non-metastatic
osteosarcoma after macroscopically complete surgical resection; it is administered by
intravenous infusion in conjunction with postoperative multiagent
chemotherapy. In the US,
mifamurtide is currently an investigational agent that holds orphan drug status for the treatment of
osteosarcoma. In a large, randomized, open-label, multicenter, phase III trial, the addition of adjuvant (postoperative)
mifamurtide to three- or four-
drug combination chemotherapy (
doxorubicin,
cisplatin, and high-dose
methotrexate with, or without,
ifosfamide) was associated with a statistically significant improvement in overall survival in patients with newly diagnosed, high-grade, non-metastatic, resectable
osteosarcoma. The pattern of outcome was generally similar in a small cohort of patients with metastatic disease who were enrolled in this trial.
Mifamurtide is generally well tolerated; adverse events attributed to administration of the
drug include
chills,
fever,
headache,
nausea, and myalgias. Based on the available data,
mifamurtide can be considered for inclusion in treatment protocols for localized
osteosarcoma.