Romurtide
A bacterial cell-wall fragment made fat-soluble, given under the skin in Japan to help white cells recover after cancer treatment
Romurtide, also published as muroctasin and MDP-Lys(L18), is the smallest immune-stimulating piece of a bacterial cell wall, muramyl dipeptide, with a lysine and an 18-carbon fatty chain added. Daiichi Pharmaceutical chose it from hundreds of such derivatives because it made the bone marrow release more white cells, and it was sold in Japan as Nopia for low white-cell counts after chemotherapy or radiotherapy. Its trials, all Japanese and mostly from 1988 to 1997, used 200 micrograms under the skin for about a week; fever was the usual side effect. It has never been approved in the United States, and we could not find a current Japanese package insert.
Used in human trials: 200 or 400 µg, Daily, or every other day, Subcutaneous (Dose-finding: leukopenia after chemotherapy or radiotherapy) Details ↓
Recommended Dosing
Used in human trials
There is no FDA label. A label from outside the US exists (see the regulatory status on this page) but was not read for this page: these are amounts given in published trials, not recommendations.
Work out syringe units → · New to syringes? · All dosing data ↓ · Dose and vial tracker · Is this vial OK?
What is it?
Bacterial cell walls are some of the strongest signals the immune system knows. In the early 1970s researchers traced the adjuvant power of whole killed mycobacteria down to a single small unit of the cell wall, N-acetylmuramyl-L-alanyl-D-isoglutamine, usually shortened to muramyl dipeptide or MDP. MDP by itself switches on macrophages and boosts immune responses in animals, but it is cleared fast and causes fever, so chemists made hundreds of variants. The group behind romurtide, at Hokkaido University and Daiichi Pharmaceutical, reports picking it from that series by how well it protected mice against bacterial infection (PMID 1618600).
The change that defines romurtide is at the end of the peptide. A lysine is attached after the isoglutamine, and that lysine's side chain carries stearic acid, an 18-carbon fat. The 'L18' in its lab name refers to that lysine and its 18-carbon acyl group. The fat makes the molecule more lipophilic, and in human monocytes in culture it was far more potent than MDP at provoking interleukin-1, interleukin-6 and tumour necrosis factor, and kept them coming for longer (PMID 7928300).
Its developers did not aim it at infection in the end. Injected under the skin, it raised white-cell and platelet counts in mice, guinea pigs and monkeys, and the explanation they found was indirect: macrophages and monocytes exposed to it release colony-stimulating factors (the growth signals that tell the bone marrow to make granulocytes and monocytes) and interleukin-6, which helps megakaryocytes mature into platelet makers. That made it a candidate for the drop in white cells that follows chemotherapy and radiotherapy (PMID 1618600).
The human work came almost entirely from Japan between 1988 and 1997. A phase 1 study in 35 healthy men found a short half-life of under three hours, a rise in neutrophils, and fever at the top dose (PMID 3263868). Trials in people whose white counts had fallen below 3,000 per cubic millimetre after chemotherapy then compared doses and schedules. In 102 such patients a daily injection beat one every other day, 400 micrograms was only slightly better than 200, and fever rose with dose, so the authors settled on 200 micrograms a day for six days (PMID 3190800). A randomised trial of 131 people with lung cancer found faster white-cell recovery on 100 or 200 micrograms than on no treatment (PMID 2719748), and a crossover trial in 20 people with lymphoma found higher white-cell and neutrophil counts at the low point of the cycle in which romurtide was given (PMID 3058133).
Several of these studies also tracked platelets. A double-blind comparison of 200 against 20 micrograms in lung cancer reported earlier recovery of both white cells and platelets on the higher dose only (PMID 2684174), and a 1995 comparison of 55 people treated for gastrointestinal cancer found platelet counts falling in 43% of those given romurtide against 80% of those who were not (PMID 8669883). These were small trials by today's standards, several were not blinded, and the endpoints were blood counts, not infections, hospital stays or survival. None of the trials read compared it with G-CSF.
It was sold in Japan under the brand Nopia; KEGG DRUG lists the trade name and classes it as an antileukopenic immunomodulator, and a 1996 lecture by its main developer described it as widely used to raise white-cell and platelet counts in cancer patients (PMID 8808264). We could not read a Japanese label: the current index of Japanese prescription package inserts lists no romurtide product, so this page cannot say whether Nopia is still sold or what its label says. It has never been approved in the United States or the European Union, it has no registered trials on ClinicalTrials.gov, and the PubMed record falls almost silent after 2000.
Romurtide is not mifamurtide (Mepact), the liposomal muramyl tripeptide approved in Europe for osteosarcoma, and it is not murabutide, a different MDP derivative tested in HIV. Each has its own entry, and their results are not romurtide's.
Mechanism of Action
Romurtide does not act on the bone marrow directly. It is read by the immune system as a fragment of bacterial cell wall, and the cells that respond release the signals that tell the marrow to make more white cells and platelets.
Monocytes release growth factors
Human blood cells exposed to it made more G-CSF (PMID 1705535), and human monocytes more interleukin-1, interleukin-6 and TNF than with MDP itself (PMID 7928300). Mouse macrophage lines switched on M-CSF (PMID 1692219). These colony-stimulating factors drive granulocyte and monocyte production.
Megakaryocytes and platelets
In guinea pigs and monkeys a rise in interleukin-6 came before more and larger megakaryocytes and faster platelet recovery (PMIDs 8167336, 9004440). Human trials reported platelet effects as well, less consistently (PMIDs 2684174, 8669883, 9350244).
Fever and inflammation come with it
The same cytokines explain its main side effect, fever, which rose with dose in patients (PMID 3190800), and the joint inflammation seen in dogs, where a neutrophil-attracting chemokine reached the joint (PMID 8926048).
Published Research
These are the studies of romurtide read from their PubMed abstracts on November 4, 2026. The human cards come first: a phase 1 study, dose-finding and randomised trials in people with low white counts after cancer treatment, and smaller studies of platelets, neutrophil function and timing during radiotherapy, almost all from Japan. Several Japanese papers are known here only from their English abstracts. The laboratory and animal cards that follow show how its developers think it works and what it did to animals at high doses. Many of the animal and safety papers appeared together in one 1988 journal supplement written largely by the manufacturer's own scientists.
Phase 1 and blood levels in healthy men
Thirty-five healthy men were given romurtide under the skin. The highest dose group ran a mild fever of about 38 °C, and redness where the needle went in was common but did not track dose; one man had a positive CRP and one a small rise in a liver enzyme that came back to normal while he was still being dosed. White counts rose, driven by neutrophils, and lymphocytes responded more strongly to mitogens. After a single 400 µg dose the peak level was about 6.9 ng/mL at roughly 1.3 hours and the half-life 2.7 hours; peaks after 100 and 200 µg rose in step with dose. The authors proposed 200 to 400 µg for patient trials.
Dose and schedule in 102 patients with leukopenia
People whose white counts had dropped during chemotherapy or radiotherapy received 200 or 400 µg under the skin, either daily for six days or every other day over five days. Daily dosing worked best, and 400 µg was only a little better than 200 µg. About 42% had a good or excellent rise in white cells, more often with solid tumours than with blood cancers. Fever was the main side effect, larger at the higher dose and on alternate days, and usually settled with fever medicine. Weighing both, the authors chose 200 µg a day for six days. There was no untreated comparison group.
Randomised trial: 131 lung cancer patients
Patients whose white count fell to 3,000 per cubic millimetre or less after a first course of chemotherapy were assigned by sealed envelope to 200 µg, 100 µg or no treatment, injected daily for six days. White cells, mainly neutrophils, came back faster in both treated groups, and bone marrow samples held more young neutrophils. In the second chemotherapy course only the 200 µg group kept the advantage. Fever and pain at the injection site were common in both treated groups. A Japanese-language report of the same trial is listed under References.
Double-blind: 200 against 20 micrograms
A review of a double-blind trial in lung cancer that compared six days of 200 µg with six days of 20 µg after chemotherapy. Only the higher dose sped the return of white cells and platelets, which the authors read as a chance to start the next chemotherapy cycle sooner. Short-lived fever was the side effect seen most often. The abstract gives no patient numbers.
Crossover trial in 20 people with lymphoma
Each patient had two cycles of the same chemotherapy and received 200 µg under the skin for ten days, starting on day 4, in one of them chosen at random. The low point of the white count came at about the same time in both cycles, but white cells and neutrophils at that low point were higher in the romurtide cycle. Seven of 20 did clearly better with it and one did better without it. About a third had side effects, mostly tolerable.
Randomised doses in urological cancer
Thirty-two people with urogenital cancer whose white count fell below 3,000 during a first chemotherapy cycle were randomised to 50 or 100 µg under the skin daily for six days; 23 to 25 could be assessed. Doctors judged the 100 µg dose better at restoring white cells. Mild fever or a reaction at the injection site occurred in 4 of 25. Published in Japanese; read from its English abstract.
Neutrophil number and function in lung cancer
Fifteen people with lung cancer and white counts of 3,000 or less after chemotherapy received 200 µg daily for seven days. Average white counts were 3,900 one day and 5,500 one week after treatment, and the authors rated 8 of 15 as improved. Of the neutrophil function tests, only one light-emission test of the response to zymosan went up; superoxide and peroxide production, movement towards a signal and bacterial killing did not change. Six had a passing fever, one with a rash. Japanese, English abstract.
Platelets during gastrointestinal cancer treatment
A comparison of 55 people treated with intensive chemotherapy, radiotherapy or both for gastrointestinal cancer, 30 given romurtide and 25 not, indexed as retrospective. Platelet counts fell in 43% of the treated group against 80% of the others, and severe drops below 60,000 occurred in 7% against 28%. In 27 people given high-dose carboplatin, white cells and platelets held up better with romurtide. Patients were not randomised, and the abstract gives no dose.
Timing alongside radiotherapy
Thirty people whose white counts fell during radiotherapy received 200 µg of Nopia under the skin on each treatment day, five days a week for two weeks. White cells, mostly neutrophils, rose from the first week through the end of dosing, then dipped a week after it stopped; platelets did not rise. Everyone finished radiotherapy, with no serious adverse events and fever in four. The authors suggested that giving it right after each radiation session was not ideal. Japanese, English abstract.
Lung immune cells in rats and patients
Compared white cells from blood with cells washed out of the airways in rats and in people with lung cancer having radiotherapy. Romurtide raised the bacteria-killing activity of the airway cells more than that of blood cells, and the authors suggest it could help prevent chest infections. The abstract gives no numbers. Japanese, English abstract.
Into the chest cavity for malignant effusion
Six people with cancer cells in fluid around the lung received a single 200 µg dose directly into the pleural space. In four, the fluid did not build up again for at least four weeks, and no major side effects were seen. Within four hours the fluid filled with neutrophils and the signalling proteins that attract and activate them; interleukin-1 beta and interleukin-6 tended to peak higher in those who responded. A six-person pilot without controls.
Human monocytes: romurtide against MDP
Both MDP and romurtide made human monocytes produce interleukin-1 (mostly the beta form), interleukin-6, tumour necrosis factor and the interleukin-1 blocker IL-1Ra. Romurtide needed far lower concentrations for the first three, kept them going longer and drew out more tumour necrosis factor; for IL-1Ra the two were alike.
G-CSF from human blood cells
Human blood mononuclear cells cultured with muroctasin produced significantly more granulocyte colony-stimulating factor, the signal specific to the neutrophil line, measured by a sensitive immunoassay and confirmed at the RNA level. The authors offer this as the reason for the neutrophil rise seen in people.
M-CSF from mouse macrophage lines
In two mouse macrophage cell lines muroctasin raised colony-stimulating factor output and switched on the M-CSF gene but not the G-CSF gene. Medium from those stimulated macrophages did raise G-CSF in a fibrosarcoma line, probably through the interleukin-1 the macrophages released.
With interferon-beta on dendritic cells and melanoma
Described as a synthetic NOD2 agonist. Human monocyte-derived dendritic cells treated with romurtide plus interferon-beta matured further and made more interleukin-12, TNF and interleukin-6 than with either agent alone, and stimulated T cells better. In mice the combination slowed B16 melanoma growth while each agent alone did not.
Faster platelet recovery after irradiation in guinea pigs
In normal guinea pigs, daily injections of 1 to 100 µg raised platelet counts in a dose-related way. After total-body X-irradiation, 100 µg a day for eight days shortened the time to normal platelet counts, preceded by more and larger megakaryocytes and an interleukin-6 level about five times that of controls. The white-cell low point was shallower, and fibrinogen rose during treatment.
Platelets after carboplatin in monkeys
Cynomolgus monkeys given carboplatin developed long-lasting low platelet counts. Romurtide under the skin raised platelets both early and during recovery, shortening the time they stayed low, and the same effect was seen when it was given by mouth.
Healthy monkeys: neutrophils, monocytes and platelets
Repeated injections under the skin raised neutrophils and monocytes in a dose-related way, and platelets too. After one 1 mg dose neutrophils climbed within a day while monocytes first fell for some hours and then rose from two to five days. Monocytes taken from the monkeys made more colony-stimulating factors, interleukin-1 and interleukin-6 when exposed to it in culture.
Leukopenia in mice: timing matters
After cyclophosphamide or X-irradiation, injections given afterwards helped mice recover their white counts in a dose-related way, with more colony-stimulating factor and more maturing granulocytes in the marrow. Given beforehand, it neither prevented nor shortened the drop. Glutathione, used as a comparator, did little either way.
Fewer metastases in mice
A 100 µg dose two to four days before tumour cells were injected cut lung metastases of B16 melanoma and colon 26 carcinoma and liver spread of a T-cell lymphoma, by injection under the skin, into a vein, into the nose, and (at 1 mg) by mouth. Five injections after tumour inoculation also reduced lung metastases, and peritoneal macrophages from treated mice killed tumour cells.
Where the drug goes and how it is broken down
Using a radiolabelled form in mice, rats, rabbits and monkeys, the drug moved quickly from the injection site; its blood half-life was under two hours in every species except rabbits (about three). Radioactivity peaked in organs within two hours, highest in the liver. Forty to fifty per cent of the dose left as exhaled carbon dioxide, because the molecule is broken down step by step to N-acetylmuramic acid, lactic acid and finally CO2.
Acute toxicity in mice, rats and dogs
The lethal dose for half of the animals, given under the skin, was 436 to 625 mg/kg in mice, 761 to 801 mg/kg in rats and above 200 mg/kg in dogs, thousands of times the human trial amounts. Toxic signs included weakness, weight loss, and crusting, necrosis and ulcers at the injection site. Intravenous doses of 90 mg/kg caused no marked toxicity in mice or rats.
Four weeks of dosing in mice and dogs
Both species developed high white counts, activated-looking lymph nodes and spleen, and irritation at the injection site, which the authors tie to the drug's intended action. Dogs also became anaemic and developed joint inflammation (synovitis).
Why it inflamed joints in rats and dogs
Rat macrophages exposed to it released interleukin-1, tumour necrosis factor, colony-stimulating factor and a neutrophil-attracting protein identified as interleukin-8-like. Joint fluid from dogs given it under the skin for 14 days, which developed swollen knees, held only the neutrophil-attracting activity. The authors propose that a chemokine pulls neutrophils into the joint lining.
Mutation tests
Negative in bacterial reverse-mutation tests with five Salmonella strains and one E. coli strain, caused no chromosome damage in Chinese hamster cells at doses that killed cells, and did not raise micronuclei in mice given up to 350 mg/kg under the skin.
The developer's overview
Traces the line from whole mycobacterial cell walls to MDP as their smallest active part, and from MDP to romurtide, chosen with a mouse model of E. coli infection. Summarises its activity against bacterial, fungal and viral infections in animals, its cytokine induction, and the clinical finding that it helped white-cell and platelet counts recover after chemotherapy or radiotherapy.
Tuberculosis research and MDP derivatives
A lecture summary on basic tuberculosis research under the US-Japan Medical Cooperative Program. In its section on cell-wall adjuvants it notes that MDP derivatives were selected as cytokine inducers and that MDP-Lys(L18) was widely used as a drug to raise white-cell and platelet counts in cancer patients. Japanese, English abstract.
Tubercle bacillus fractions, from lab to clinic
A personal review by romurtide's lead developer of decades of work on mycobacterial cell walls. His group synthesised several hundred MDP derivatives and picked romurtide as the cytokine inducer to take into people, where it was used in cancer patients to restore monocytes, neutrophils and platelets. Japanese, English abstract.
Dosing Data
Romurtide was sold in Japan as Nopia, but we could not read a Japanese package insert: the current index of Japanese prescription inserts lists no romurtide product, and there is no FDA label because it was never approved in the US. Every row below is an amount a published human study gave, taken from its abstract. The patient trials enrolled people whose white counts had already fallen after chemotherapy or radiotherapy and gave the drug under medical supervision with repeated blood counts.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Romurtide is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
An arithmetic example, not a recommendation: a 5 mg vial mixed with 2 mL of bacteriostatic water holds 2,500 mcg per mL, so every 10 units on a U-100 insulin syringe hold 250 mcg. 200 µg, the first amount in the “Dose-finding: leukopenia after chemotherapy or radiotherapy” row (200 or 400 µg) is 8.0 units (0.080 mL). If your vial or water differ, the numbers change: use the reconstitution calculator.
Source: dose: Used in human trials, PMID 3190800 (Dosing Data below); vial and water: the calculator's default example, not a vial size we have a source for.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Romurtide, before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Romurtide stays intact once mixed.
How it is taken
As it was given in human studies: Subcutaneous (Daily, or every other day; Dose-finding: leukopenia after chemotherapy or radiotherapy).
For injection technique, sites and needle disposal, see the mixing guide.
Source: Used in human trials: the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: a half-life of 2.7 ± 0.8 h after a single 400 µg dose under the skin. After about five half-lives almost none is left.
How long the doses were given: Dose-finding: leukopenia after chemotherapy or radiotherapy: 6 days (daily) or 5 days (alternate); Randomised trial: lung cancer chemotherapy: 6 days; Crossover trial: lymphoma chemotherapy: 10 days, from day 4 of the cycle.
When effects appear: unknown; no source on this page gives a time to effect for Romurtide. Results reported in the studies are under Published Research.
Source: half-life: PMID 3263868; Used in human trials, the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: Fever, the most common effect, larger at 400 than 200 µg and with alternate-day dosing; usually eased by fever medicine (PMID 3190800); A rise to about 38 °C at the highest phase 1 dose in healthy men (PMID 3263868); Redness, pain or a reaction at the injection site (PMIDs 3263868, 2719748, 2660519); Rash with fever in one of 15 lung cancer patients (PMID 2919891); Side effects of any kind in about a third of lymphoma patients, mostly tolerable (PMID 3058133); In animals: joint inflammation and anaemia in dogs given it for four weeks (PMID 3190795), and ulcers and necrosis at the injection site at very high doses (PMID 3190794). Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Romurtide. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“From the human studies carded above; the toxicology findings in animals follow”).
Interactions
Unknown: a PubMed search for human interaction studies of Romurtide (reviewed 2026-11-04) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Romurtide products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder; it checks the measured mass against Romurtide's expected mass, 887.1 Da, from this entry's molecular data. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Not FDA Approved. Elsewhere: approved in Japan (Nopia). Sport: Unsettled (S0 may apply).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
From the human studies carded above; the toxicology findings in animals follow.
Contraindications & Cautions
We could not read a Japanese label, so no official list of contraindications is given here. These cautions come from the studies.
Legal Status
Romurtide was approved in Japan as Nopia and has never been approved in the US or the EU.
Frequently Asked Questions
?What is romurtide?
A synthetic version of muramyl dipeptide, the immune-stimulating fragment of bacterial cell walls, with a lysine carrying an 18-carbon fatty chain added. It is also called muroctasin and MDP-Lys(L18), and it was sold in Japan as Nopia.
?What was it used for?
To help white-cell counts recover in people whose counts fell after chemotherapy or radiotherapy. Japanese trials from 1988 to 1997 found faster recovery of white cells, and in some studies platelets, compared with no treatment or a lower dose (PMIDs 2719748, 2684174, 8669883).
?How does it compare with filgrastim (G-CSF)?
No trial compared them. Romurtide works indirectly, by making the body's own monocytes and macrophages release G-CSF and other growth factors (PMID 1705535); filgrastim is G-CSF itself. Romurtide's trials measured blood counts only, not infections or survival.
?What doses were used?
Most trials gave 200 µg under the skin once a day for six days, the regimen its dose-finding study chose (PMID 3190800); others used 100 µg, 400 µg or ten days. These are study amounts, not a recommendation.
?What are the side effects?
Fever was the most common and rose with dose (PMID 3190800), followed by redness or pain at the injection site. Dogs given it for weeks developed joint inflammation (PMID 3190795).
?Is it the same as mifamurtide?
No. Mifamurtide (Mepact) is a muramyl tripeptide joined to a phospholipid and packaged in liposomes, approved in Europe for osteosarcoma. Romurtide is a different MDP derivative with a different use.
?Is it approved in the US?
No. Drugs@FDA holds no application for it (November 4, 2026), and no US trial is registered.
References
- [clinical-trial] Ichihara N, et al. "Phase I study and clinical pharmacological study of muroctasin." Arzneimittelforschung, 1988;38(7A):1043-69. PMID: 3263868.
- [clinical-trial] Tsubura E, et al. "Restorative activity of muroctasin on leukopenia associated with anticancer treatment." Arzneimittelforschung, 1988;38(7A):1070-4. PMID: 3190800.
- [clinical-trial] Hiraoka A, et al. "Hematological response to the new synthetic muramyl dipeptide derivative muroctasin after chemotherapy in patients with malignant lymphoma. A randomized crossover trial." Arzneimittelforschung, 1988;38(10):1499-501. PMID: 3058133.
- [clinical-trial] Fukuoka M, et al. "Restorative effect of muroctasin on leukopenia caused by anticancer chemotherapy in lung cancer. Comparative study by envelope method." Arzneimittelforschung, 1989;39(1):90-3. PMID: 2719748.
- [clinical-trial] Furuse K, et al. "Activation of the cytokine network by muroctasin as a remedy for leukopenia and thrombopenia." Arzneimittelforschung, 1989;39(8):915-7. PMID: 2684174.
- [clinical-trial] Oishi K, et al. "[Restorative effect of muroctasin; MDP-Lys (L18) [DJ-7041] on leukopenia in urogenital cancer patients treated with chemotherapy]." Hinyokika Kiyo, 1989;35(3):527-36. PMID: 2660519.
- [clinical-trial] Hirota M, et al. "[Activation of neutrophil function by MDP-Lys(L 18)]." Gan To Kagaku Ryoho, 1989;16(2):219-24. PMID: 2919891.
- [clinical-trial] Yano K, et al. "Restorative effect of romurtide for thrombocytopenia associated with intensive anticancer drug treatment and/or irradiation in patients with gastrointestinal cancer." Anticancer Res, 1995;15(6B):2883-7. PMID: 8669883.
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- [clinical-trial] Yanagawa H, et al. "Intrapleural therapy with MDP-Lys (L18), a synthetic derivative of muramyl dipeptide, against malignant pleurisy associated with lung cancer." Lung Cancer, 2000;27(2):67-73. PMID: 10688489.
- [pubmed] Suzuki K, et al. "Differences in interleukin 1 (IL-1), IL-6, tumor necrosis factor and IL-1 receptor antagonist production by human monocytes stimulated with muramyl dipeptide (MDP) and its stearoyl derivative, romurtide." Immunopharmacology, 1994;28(1):31-8. PMID: 7928300.
- [pubmed] Shimoda K, et al. "Muroctasin [MDP-Lys(18)] augments the production of granulocyte colony-stimulating factor (G-CSF) from human peripheral blood mononuclear cells in vitro." Int J Immunopharmacol, 1990;12(7):729-36. PMID: 1705535.
- [pubmed] Akahane K, et al. "Stimulation of macrophages by muroctasin to produce colony-stimulating factors." Arzneimittelforschung, 1990;40(2 Pt 1):179-83. PMID: 1692219.
- [pubmed] Fujimura T, et al. "A synthetic NOD2 agonist, muramyl dipeptide (MDP)-Lys (L18) and IFN-β synergistically induce dendritic cell maturation with augmented IL-12 production and suppress melanoma growth." J Dermatol Sci, 2011;62(2):107-15. PMID: 21411292.
- [pubmed] Namba K, et al. "Enhancement of platelet recovery in X-irradiated guinea pigs by romurtide, a synthetic muramyl dipeptide derivative." Blood, 1994;83(9):2480-8. PMID: 8167336.
- [pubmed] Namba K, et al. "Romurtide, a synthetic muramyl dipeptide derivative, accelerates peripheral platelet recovery in nonhuman primate chemotherapy model." Vaccine, 1996;14(14):1322-6. PMID: 9004440.
- [pubmed] Nakajima R, et al. "Stimulatory effect of romurtide on hematopoiesis in monkeys." Arzneimittelforschung, 1991;41(1):60-5. PMID: 2049113.
- [pubmed] Nakajima R, et al. "Beneficial effect of muroctasin on experimental leukopenia induced by cyclophosphamide or irradiation in mice." Arzneimittelforschung, 1988;38(7A):986-92. PMID: 3263871.
- [pubmed] Yoo YC, et al. "MDP-Lys(L18), a lipophilic derivative of muramyl dipeptide, inhibits the metastasis of haematogenous and non-haematogenous tumours in mice." Vaccine, 1994;12(2):175-60. PMID: 8147100.
- [pubmed] Ono K, et al. "Metabolic disposition of 14C-muroctasin in laboratory animals." Arzneimittelforschung, 1988;38(7A):1009-14. PMID: 3190792.
- [pubmed] Ono Y, et al. "Acute toxicity of muroctasin in mice, rats and dogs." Arzneimittelforschung, 1988;38(7A):1022-4. PMID: 3190794.
- [pubmed] Ono Y, et al. "Subacute toxicity of muroctasin in mice and dogs." Arzneimittelforschung, 1988;38(7A):1024-7. PMID: 3190795.
- [pubmed] Sugawara T, et al. "Inflammatory cytokine production induced by an analogue of muramyl dipeptide MDP-Lys(L18) in rat macrophage cultures and dog synovial fluid." Inflammation, 1996;20(1):43-56. PMID: 8926048.
- [pubmed] Shimada H, et al. "Mutagenicity studies of muroctasin." Arzneimittelforschung, 1988;38(7A):1031-3. PMID: 3056424.
- [review] Azuma I. "Review: inducer of cytokines in vivo: overview of field and romurtide experience." Int J Immunopharmacol, 1992;14(3):487-96. PMID: 1618600.
- [review] Azuma I. "[Basic studies on tuberculosis and tubercle bacilli in U.S.-Japan medical cooperative program tuberculosis panel]." Kekkaku, 1996;71(1):19-23. PMID: 8808264.
- [review] Azuma I. "[Biochemical and immunological properties of the fractions of tubercle bacilli]." Kekkaku, 1998;73(2):65-70. PMID: 9545698.
- [pubmed] Takada M, et al. "[Restorative effect of muroctasin, MDP-Lys (L 18), on leukopenia caused by anticancer chemotherapy in lung cancer--comparative study by envelope method]." Gan To Kagaku Ryoho, 1988;15(11):3095-101. PMID: 3142367.
- [pubmed] Azuma I. "Development of the cytokine inducer romurtide: experimental studies and clinical application." Trends Pharmacol Sci, 1992;13(12):425-8. PMID: 1293866.
- [pubmed] Azuma I, et al. "Potentiation of host defense mechanism against infection by a cytokine inducer, an acyl-MDP derivative, MDP-Lys(L18) (romurtide) in mice and humans." Med Res Rev, 1994;14(4):401-14. PMID: 8084203.
- [pubmed] Okawa T, et al. "Restorative effect of MDP-Lys (L18) on leukopenia of cancer patient treated with radiotherapy." Nihon Igaku Hoshasen Gakkai Zasshi, 1988;48(4):514-22. PMID: 3231516.
- [pubmed] Nitta Y, et al. "Inhibitory effect of liposomal MDP-Lys on lung metastasis of transplantable osteosarcoma in hamster." Oncol Res, 2000;12(1):25-31. PMID: 11061343.
- [other] FDA Global Substance Registration System, Romurtide, UNII SUP956TPT6 (chemical; JAN, INN 6406; brand name Nopia; CAS 78113-36-7; MeSH C036866; ChEMBL CHEMBL1908331), read November 4, 2026: formula C43H78N6O13, molecular weight 887.11; N-acetylmuramyl-L-alanyl-D-isoglutaminyl-N6-stearoyl-L-lysine. https://gsrs.ncats.nih.gov/ginas/app/beta/substances/SUP956TPT6
- [other] KEGG DRUG D01722: Romurtide (JAN/INN); Nopia (trade name); efficacy antileukopenic, immunomodulator; formula C43H78N6O13, molecular weight 887.11. Read November 4, 2026. https://www.kegg.jp/entry/D01722
- [other] KEGG MEDICUS, index of Japanese prescription drug package inserts (edition of October 21, 2026), searched November 4, 2026 for romurtide, ロムルチド and ノピア: no product found. https://www.kegg.jp/medicus-bin/search_drug?display=med&search_keyword=romurtide
- [other] ChEMBL molecule CHEMBL1908331 (ROMURTIDE), read November 4, 2026: synonyms Nopia, Romurtida, Romurtide; full formula C43H78N6O13, 887.13; highest clinical phase recorded 2. https://www.ebi.ac.uk/chembl/compound_report_card/CHEMBL1908331/
- [registry] ClinicalTrials.gov API v2, read November 4, 2026: no study lists romurtide or muroctasin as an intervention. https://clinicaltrials.gov/search?intr=romurtide
- [other] US FDA, Drugs@FDA and the drug label endpoint (openFDA), searched November 4, 2026: no application and no label record for romurtide.
Sources & Citations
The 28 studies carded above and the five References-only papers were read from their PubMed records on November 4, 2026; several Japanese papers only through their English abstracts. Identity comes from the FDA Global Substance Registration System (UNII SUP956TPT6), KEGG DRUG (D01722) and ChEMBL (CHEMBL1908331); Japanese product status from KEGG DRUG and the KEGG MEDICUS index of Japanese package inserts; trial registration from ClinicalTrials.gov; US status from Drugs@FDA and openFDA, all read the same day. No Japanese label was read. Grey Peptides sells nothing and links to no vendor.
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