Mifamurtide (Mepact)_Dosage, benefits & legal status
Also known as Mepact, Junovan, L-MTP-PE, MTP-PE, CGP-19835A
A synthetic bacterial cell-wall fragment that activates macrophages, approved in Europe for osteosarcoma but not in the US.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Mifamurtide (Mepact)?
Plain language first. The technical label stays, but it never stands alone.Overview
Given into a vein, the liposomes are taken up by macrophages and switch them on to attack any tumour cells left after surgery. Added to chemotherapy for osteosarcoma, it raised 6-year survival from 70% to 78% in a large trial. The EU approved it in 2009; an FDA panel found the evidence insufficient in 2007, and it is not approved in the US.
Mifamurtide is muramyl tripeptide phosphatidylethanolamine (MTP-PE): a three-amino-acid chain on a bacterial cell-wall sugar, joined to a fat so it sits in liposomes. Ciba-Geigy made it in the early 1980s, IDM Pharma brought it to market, and Esteve now sells it as Mepact.
What it's used for
A hospital IV add-on to chemotherapy for non-metastatic osteosarcoma in Europe. Fever and chills after infusions are near universal.
How does Mifamurtide (Mepact) work?
What it does in the body, and where.Mifamurtide is a fully synthetic relative of muramyl dipeptide, the smallest immune-stimulating part of mycobacterial cell walls, with an extra alanine and a phospholipid tail.
- 01NOD2MTP-PE binds NOD2, a sensor inside monocytes, dendritic cells and macrophages that recognises bacterial cell-wall fragments.
- 02Macrophages switched onActivated cells release TNF-alpha, IL-1 beta, IL-6, IL-8 and IL-12 and raise adhesion molecules. The idea is that they then kill tumour cells left after surgery; how it works in osteosarcoma is not fully understood.
- 03LiposomesThe lipid tail anchors it in liposomes sized for macrophages to take up. An earlier free form caused harmful side effects.
A schematic of the compound's mechanism, not a diagnostic image.
What else is it used for?
Each group carries its own evidence level.Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
Osteosarcoma
Clinical use- Human trialChildren's Oncology Group trial, 2x2 factorial: 6-year overall survival 78% with MTP against 70% without (HR 0.71, P=.03); event-free survival P=.08.
- RegulatoryThe 2005 report found an ifosfamide-by-MTP interaction that blocked the planned analysis; the 2008 update found none. The FDA panel voted 12 to 2 that the evidence was not substantial.
- No dataThe trial was open-label, with no placebo.
Trial size is quoted as 662, 664, 677, 678 or about 800 depending on the source and population; 678 is the EU intention-to-treat group. The EPAR summary's 68% against 61% are crude proportions alive without recurrence, not survival estimates, and happen to match two single arms in the 2005 paper. The 2005 analysis found an ifosfamide interaction that blocked the planned comparison, and the 2008 update did not. Some listings say it acts through TLR4; the EU label says NOD2. It is not approved in the US. It is better described as a lipid-linked muramyl tripeptide than a conventional peptide drug.
The published record
Papers and trials about Mifamurtide (Mepact)
126 papers tagged human · 69 not reviews or lab · 28 clinical trial publications
13 registered trials · 1 with posted results
Furthest stage reached: Approved outside the US, European Union, United Kingdom
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count.
At a glance
Four things to know about Mifamurtide (Mepact)
Evidence
Clinical use
Category
Immune support
Common vial
Varies
Half-life
About 2 hours
How much, and do you cycle it?
The range, and whether you take breaks.2 mg/m2 per infusion (EU label), twice weekly for 12 weeks, then weekly for 24 weeks. One 36-week course Clinical use
48 infusions over 36 weeks, twice weekly then weekly, given alongside post-operative chemotherapy. There is no repeat course.
About 2 hoursclinical-guideline
2.05 +/- 0.40 hours in 21 healthy adults and 2.04 hours in osteosarcoma patients; no build-up over the course. Radiolabel goes mainly to the liver, spleen, nasopharynx and thyroid. About 3.2 hours in moderate liver impairment.
Source: Mepact EU SmPC section 5.2
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
2 mg per square metre of body surface as a 1-hour infusion into a vein, never as a bolus: twice weekly, at least 3 days apart, for 12 weeks, then weekly for 24 weeks, 48 infusions over 36 weeks alongside chemotherapy. Reconstituted from a 4 mg vial and filtered through the supplied filter. No premedication is specified. A hospital infusion dosed by body surface, so no vial draw applies.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized Mifamurtide (Mepact) keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- Ciclosporin or other calcineurin inhibitors at the same time
- High-dose NSAIDs at the same time: they can block its effect on macrophages
- Routine or long-term corticosteroids
- Pregnancy, or childbearing potential without effective contraception
- Over 30 years old: not enough data to recommend it
Stop and get help
- Fever or chills lasting more than 8 hours after an infusion: needs checking for sepsis
- Wheezing or trouble breathing during or after an infusion
- Chest pain or sudden breathlessness, since fluid around the heart has been reported
Common effects
- Chills in 89%, fever in 85% and tiredness in 53% in early single-agent studies
- Nausea in 57%, vomiting in 44% and headache in 50%
- Mild to moderate fast heart rate in 50%
- Hearing loss in 12% against 7% with chemotherapy alone in the main trial, not clearly caused by mifamurtide
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Mifamurtide (Mepact) approved?
And where the numbers on this page come from.Not in the United States. Mifamurtide (Mepact) has no FDA approval. It is approved in the European Union and the United Kingdom.
- Approval statusClinical use
- RouteInto a vein (1-hour infusion), in hospital
- Checked12 October 2026
- Approved outside the USEuropean Union, United Kingdom: Authorised in the EU on 6 March 2009 as Mepact for non-metastatic osteosarcoma after surgery, given with chemotherapy; studied in patients aged 2 to 30. Current holder Esteve. Also authorised in the UK. Not approved in the US.This does not change the United States position above.
- DoseFrom product labeling and clinical guidelines.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesEMA, Mepact EPARMepact EU summary of product characteristicsEMA, Mepact EPAR summary for the publicMeyers PA et al., Journal of Clinical Oncology 2008;26:633-638Meyers PA et al., Journal of Clinical Oncology 2005;23:2004-2011Cancer Network, FDA advisory committee coverage (May 2007)ClinicalTrials.gov, MSKCC expanded access (NCT04571229)FDA GSRS substance record, mifamurtide (UNII 1LM890Q4FY)
What has happened recently
Not approved in the US. An FDA advisory committee voted 12 to 2 in May 2007 that the main trial did not provide substantial evidence of effectiveness, and a not-approvable letter followed in August 2007; it remains available in the US only through expanded access. The EU authorised Mepact on 6 March 2009 and renewed it with unlimited validity in 2019; the holder moved from IDM to Takeda in 2013 and to Esteve in 2025. It is also authorised in the UK.
You can compare this against the whole library, or read how to check a seller.
What else is like Mifamurtide (Mepact)?
Others in Immune support, side by side.If you're weighing Mifamurtide (Mepact), it's worth reading P140 (forigerimod), Pexiganan, and Splenopentin in the same class.
A synthetic bacterial cell-wall fragment that activates macrophages, approved in Europe for osteosarcoma but not in the US.
- Dose
- 2 mg/m2 per infusion (EU label)
- How often
- Twice weekly for 12 weeks, then weekly for 24 weeks
An experimental lupus peptide whose pivotal trial missed its endpoint in 2018.
- Dose
- 200 mcg every 4 weeks (every trial to date)
- How often
- Every 4 weeks
A magainin-based antimicrobial cream, tested twice for diabetic foot infections and never approved.
- Dose
- 0.8% cream twice daily (last trials)
- How often
- Twice daily for 14 days (trials)
A five-amino-acid spleen peptide, sold on an evidence base almost nobody has read.
- Dose
- Research only
- How often
- Not established
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
Sources
- EMA, Mepact EPAR(2026)Authorised 6 March 2009; holder Esteve Pharmaceuticals. EU orphan designation removed in 2019 at the end of market exclusivity.
- Mepact EU summary of product characteristics(2026)2 mg/m2 twice weekly for 12 weeks then weekly for 24 weeks. NOD2 ligand. 678 patients: 6-year overall survival HR 0.72 (0.53 to 0.97), p=0.0313. Half-life 2.05 hours. Chills 89%, fever 85%.
- EMA, Mepact EPAR summary for the public(2009)678 patients aged 1 to 31, followed up to 10 years; 68% against 61% survived without recurrence (crude counts); risk of death reduced 28%.
- Meyers PA et al., Journal of Clinical Oncology 2008;26:633-638(2008)Children's Oncology Group: adding MTP to chemotherapy raised 6-year overall survival from 70% to 78% (P=.03, HR 0.71); event-free survival showed a trend (P=.08); no interaction with ifosfamide in the updated analysis.
- Meyers PA et al., Journal of Clinical Oncology 2005;23:2004-2011(2005)677 patients, 2x2 factorial design. An interaction between ifosfamide and MTP prevented the planned factorial analysis.
- Cancer Network, FDA advisory committee coverage (May 2007)(2007)The primary disease-free survival endpoint showed no significant advantage; the survival analysis was not prespecified and follow-up was incomplete. (Trade press.)
- ClinicalTrials.gov, MSKCC expanded access (NCT04571229)(2026)Expanded access available in the US; states that L-MTP-PE is investigational and not FDA-approved for any condition.
- FDA GSRS substance record, mifamurtide (UNII 1LM890Q4FY)(2026)Sodium salt monohydrate, C59H108N6O19P.Na.H2O, MW 1277.5; N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine linked to dipalmitoyl phosphatidylethanolamine.
Beyond these, 234 records are indexed. Browse the records