Mifamurtide (L-MTP-PE) for High-Risk Osteosarcoma

The drug being tested in this study is called mifamurtide (L-MTP-PE; liposomal muramyl tripeptide phosphatidyl ethanolamine). Mifamurtide is being used to treat people with osteosarcoma, a form of cancer.

This was a patient-access study that looked at adverse events, disease progression, and overall survival in study participants.

The study enrolled 205 patients, of whom 204 were treated with mifamurtide intravenously at a dose of 2 mg/m2 twice weekly (at least 3 days apart) for 12 weeks, and then weekly for an additional 24 weeks, for a total of 48 doses in 36 weeks (following surgery for primary or metastatic disease).

This study was conducted in the United States. Participants could receive treatment for up to 9 months. This study was previously mis-categorized as an interventional study.

Inclusion criteria

• Had signed informed consent/assent. Voluntary participation in the pharmacokinetic portion of the compassionate access protocol was included in the informed consent but not required for compassionate use participation.
• Had diagnosis of high grade osteosarcoma with relapsed or recurrent disease, locally or metastatic, with disease not completely resectable or who were unable to complete recommended chemotherapy due to toxicity: relapse, recurrence local or metastatic; unable to have standard surgical resection; abbreviated chemotherapy regimen secondary to toxicity (e.g. hypophosphatemia from ifosfamide, cardiotoxicity from doxorubicin, renal dysfunction from methotrexate, ifosfamide, or cisplatin.)
• Aged 2 ≤ 50 years.
• Had adequate hematopoietic function as demonstrated by: 1) Absolute Neutrophil Count (ANC) > 750/microL; Hemoglobin (Hb) > 8 g/dL; Platelets > 30,000/microL.
• Had adequate hepatic function as documented by 1) ALT < 2.5 x upper limit of normal (ULN) for age; 2) total bilirubin ≤ 1.5 x ULN for age.
• Had adequate renal function as demonstrated by: 1) Creatinine clearance or radioisotope glomerular filtration rate > 70 mL/min/1.73 m^2; OR, 2) Serum creatinine ≤ 2x ULN for age.
• Had absence of concurrent active acute infection (i.e., afebrile).
• In females of child bearing potential (not menopausal for 12 months or no previous surgical sterilization), had a negative pregnancy test. All sexually active participants used an effective means of contraception. Such means included oral contraceptives, Lupron Depot, DepoProvera, and condom with diaphragm and spermicidal jelly.
• Performance status: Lansky 50-100% (≤ 16 years of age); OR, Eastern Cooperative Oncology Group (ECOG) 0-2 or Karnofsky 50-100% (>16 years of age).

Exclusion criteria

• Had chronic use of corticosteroids or other immunosuppressive agents.
• Was pregnant or breast-feeding.