Omiganan (MBI-226)_Dosage, benefits & legal status
Also known as MBI 226, MX-226, CPI-226, Omigard, CLS001, MBI 594AN, omiganan pentahydrochloride
A short, tryptophan- and arginine-rich peptide gel that disrupts microbial membranes. Two catheter-site phase 3 trials missed their primary endpoints, and its two rosacea phase 3 trials split, one positive and one negative.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Omiganan (MBI-226)?
Plain language first. The technical label stays, but it never stands alone.Overview
Germs on the skin around an intravenous catheter can infect the insertion site and spread into the blood, and omiganan was a germ-killing peptide gel meant to stop that. In the 1,859-patient CLIRS trial, local catheter-site infections occurred in 6.3% against 8.6% with povidone-iodine, short of statistical significance (p=0.082), after an earlier phase 3 had also missed its bloodstream infection endpoint (2.2% against 2.6%). Later skin trials were mixed: one rosacea phase 3 was positive and the other negative, and small studies in eczema, HPV lesions and seborrheic dermatitis were mostly negative. It was never approved and is sold only as a laboratory reagent.
Omiganan is a linear 12-residue cationic peptide amide, ILRWPWWPWRRK-NH2, rich in tryptophan and arginine and described as an indolicidin analog and a synthetic cathelicidin-family antimicrobial peptide. It binds the negatively charged surfaces of bacteria and fungi and disrupts their membranes, with in vitro activity against Gram-positive bacteria (MIC50/90 4 mg/L for coagulase-negative staphylococci and 16 mg/L for S. aureus regardless of methicillin resistance), variable Gram-negative activity and Candida; in human blood cells it also boosts interferon-alpha release to TLR3, 7, 8 and 9 ligands mainly through plasmacytoid dendritic cells, as LL-37 does. Formulated as the pentahydrochloride in a topical gel, it went through two phase 3 trials for preventing catheter-site infections (run by Micrologix, then by Cadence until it ended that program on March 12, 2009) and dermatology trials under Cutanea and Maruho, the last published in 2023.
What it's used for
Nothing in medicine. It was tested as a gel to prevent catheter-site infections and to treat rosacea and other skin conditions, and it is now sold only as a laboratory reagent.
How does Omiganan (MBI-226) work?
What it does in the body, and where.Omiganan, like pexiganan, is a short, positively charged peptide that kills microbes by breaking their membranes; it also nudges the skin's immune response.
- 01Drawn to microbesIts three arginines and one lysine carry positive charges that pull it toward the negatively charged surfaces of bacteria and fungi. There is no receptor: the target is the membrane itself.
- 02Breaking the membraneA stretch of four tryptophans broken by two prolines pushes into the membrane and disrupts it, killing the microbe quickly. In lab tests it was active against Gram-positive bacteria, including S. aureus at 16 mg/L whether or not it was methicillin-resistant, against Candida, and variably against Gram-negative bacteria.
- 03An immune nudgeIn human blood cells it boosts the release of interferon-alpha in response to molecules that trigger the immune sensors called toll-like receptors 3, 7, 8 and 9, mainly through plasmacytoid dendritic cells, much as the human peptide LL-37 does. That effect was the reason for the HPV wart and vulvar lesion trials; neither found a clinical benefit.
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.
Catheter sites, first phase 3
tested-and-failed- Human trial1,452 enrolled, 1,392 analyzed, open-label with blinded adjudication, against 10% povidone-iodine: catheter-related bloodstream infection 2.2% against 2.6% (p=0.966), missing the primary endpoint.
- Human trialCatheter colonization 31% against 40% (p=0.002) and local catheter-site infection 3.5% against 6.9% (p=0.004), the source of the widely quoted 49% reduction.
- No dataNo peer-reviewed full publication was found; the figures come from company filings.
Catheter sites, CLIRS phase 3
tested-and-failed- Human trial1,859 randomized at 58 sites in the US and Europe, open-label with blinded adjudication: local catheter-site infection 6.3% against 8.6% (difference 2.25 points, 95% CI -0.30 to 4.81; p=0.082).
- Human trialMicrobiologically confirmed site infection 3.9% against 7.6% (p=0.002) and colonization 43.7% against 55.1% (p<0.001), with no adjustment for multiple comparisons.
- RegulatoryEnrollment was raised from 1,250 to 1,850 with FDA agreement in July 2007, under a Special Protocol Assessment; Cadence ended the program on March 12, 2009.
Rosacea phase 3 trials
Investigational- Human trialNCT02547441, 463 randomized, 12 weeks: inflammatory lesions -18.1 against -13.5 on the plain gel (p=0.043) and a 2-grade improvement in 26.3% against 16.9% (p=0.019), meeting both co-primary endpoints.
- Human trialNCT02576860, 263 randomized: -19.8 against -20.9 (p=0.799) and 24.6% against 25.6% (p=0.858), meeting neither.
- No dataResults were posted in July and August 2022, after the trials ended in 2017 and 2018.
Atopic dermatitis (Leiden)
tested-and-failed- Human trial36 randomized, one lesion treated once daily for 28 days: at 2.5%, an eczema severity score on the treated patch (oSCORAD) fell 18.5% more than with vehicle (95% CI -32.9 to -1.0; p=0.04) and morning itch fell 8.2 more (p=0.05), short of the 20 to 30 points counted as clinically important; 1% was not significant.
- Human trialStaphylococcus abundance on the skin fell from 70% to 42% (p=0.01).
- Human trialA second trial in 80 patients, twice daily on all lesions for 28 days, found no significant clinical improvement, though Staphylococcus fell.
HPV lesions (Leiden)
tested-and-failed- Human trialAnogenital warts, 24 randomized 2 to 1, 2.5% once daily for 12 weeks: no difference in clearance, count or size; wart height -30.3% (p=0.054); HPV load -96.6% against placebo (95% CI -99.9 to -7.4%; p=0.045).
- Human trialVulvar HSIL, 12 randomized 2 to 1: no difference in lesion size (p=0.79), tissue findings or viral load.
- Human trialBlood was sampled only in the vulvar HSIL trial, and omiganan was undetectable in every sample.
It is sometimes reported as failing one primary infection-prevention endpoint; there were two catheter phase 3 trials with different primary endpoints, bloodstream infection in the first and local catheter-site infection in CLIRS, and both missed. Its current development status is often described as unknown: a Maruho- and Cutanea-funded seborrheic dermatitis trial ran from November 2019 to January 2022 and was negative, and nothing has been reported since. The widely quoted 49% reduction in local catheter-site infections comes from the original analysis of the first phase 3 (3.5% against 6.9%, described by Micrologix as local tunnel infections); a stricter re-analysis gave a 41.9% reduction (3.5% against 6.1%), and the trial's primary endpoint was missed. A 21% reduction in colonization is also quoted; the figures were 31% against 40%, a 9-point difference. The first phase 3 is reported as 1,400, more than 1,400 or 1,407 patients (Cadence, at 27 US centers); 1,452 were enrolled, 1,407 evaluated for safety and 1,392 analyzed. CLIRS is described as double-blind in a Cadence filing, but the registry and the company's 2007 release describe an open-label trial with blinded adjudication. Some drug databases label omiganan a small molecule; it is a 12-residue peptide.
The published record
Papers and trials about Omiganan (MBI-226)
52 papers tagged human · 23 not reviews or lab · 6 clinical trial publications
18 registered trials · 5 with posted results
Furthest stage reached: Phase 3, results posted
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 Omiganan (MBI-226)
Evidence
Investigational
Category
Immune support
Common vial
Varies
Half-life
Not established
How much, and do you cycle it?
The range, and whether you take breaks.1% gel at catheter sites, 1.6% gel on rosacea (phase 3 trials), each dressing change (catheters) or once daily (rosacea). Courses of 28 days to 12 weeks in trials; never marketed Trial dose
The catheter trials applied it for as long as the line stayed in, renewed at each dressing change, for up to 28 days in the first phase 3. The skin trials ran 28 days to 12 weeks, and one rosacea safety study ran up to 12 months. No product exists, so there is no schedule to plan around.
Not establishedNo figure
Applied to the skin only. No half-life, peak time or bioavailability has been published, and in the vulvar HSIL trial omiganan was undetectable in all blood samples. How it is cleared has not been described.
Source: Rijsbergen M et al., British Journal of Clinical Pharmacology 2020 (blood sampling in the vulvar HSIL trial)
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What does it cost?
Typical dose and cost, in plain numbers.Omiganan (MBI-226) is not injected
It is taken on the skin (topical gel). Applied to the skin as a gel in every trial. The catheter trials spread 1% omiganan pentahydrochloride gel on the skin around the insertion site after the catheter went in and at each dressing change (every 3 days in CLIRS, for up to 28 days in the first phase 3); CLIRS also used a povidone-iodine scrub before insertion. The rosacea phase 3 trials used a 1.6% w/w gel once daily for 12 weeks, after a phase 2 compared 1% once daily with 2.5% once or twice daily. The Leiden skin studies used 1%, 1.75% or 2.5% once or twice daily for 28 days, and 2.5% once daily for 12 weeks on warts and vulvar lesions, at most 37.5 mg a day. The early acne trials used 1.25% to 5%. The gels were made for trials only, and no product was ever sold.
How do you store it?
Before mixing, and after.Room temperature, out of light. Cap it tight after each use.
Omiganan (MBI-226) ships as a cream, gel, or serum. Keep it at room temperature away from sun and heat unless the label says otherwise. Refrigerating an emulsion can split the texture. Watch for color, smell, or separation changes and stop using it if any appear.
What are the side effects and cautions?
Known cautions and warnings for this compound.Solubility, computed: 50% charged residues, 67% hydrophobic. Water usually sufficient.
A first-pass rule from peptide manufacturers' guidance. It does not account for disulfide bridges, salt form or how the powder was dried, and it predicts what should be easy rather than what will happen in your vial.
Who should avoid it
- Not studied in pregnancy or breastfeeding: no data exist
- Not studied by injection or by mouth: every trial applied it to the skin as a gel
- Not studied as a replacement for catheter care: in CLIRS it was added after a povidone-iodine scrub before insertion
- Use outside a trial: it was never approved, and what is sold is a laboratory reagent for research use, not a medical product
Stop and get help
- Spreading redness, warmth, pus or pain at a catheter site, or fever and chills: signs of an infection that needs medical care
- Burning, pain or a rash where the gel is applied that gets worse instead of settling: application-site pain and dermatitis were the main side effects in the rosacea trials
Common effects
- Rosacea phase 3 NCT02547441: non-serious adverse events 35.3% against 36.4% on the plain gel; headache 7.7% against 6.1%; application-site dermatitis 2.1% against 0.4% and pain 2.1% against 3.5%; serious adverse events 1.70% against 1.75%
- Rosacea phase 3 NCT02576860: non-serious adverse events 34.6% against 28.4%; application-site pain 6.6% against 1.6%; treatment-related events 14.0% against 13.4%, with 6 withdrawals for side effects in each arm
- Up to 12 months of open-label use in 307 people with rosacea: treatment-related adverse events in 48 (about 16%), serious adverse events in 2.3% and 27 stopping for side effects, with no deaths
- First catheter phase 3: no serious drug-related adverse events and about 2% minor treatment-related events, no different from povidone-iodine
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Omiganan (MBI-226) approved?
And where the numbers on this page come from.No. Omiganan (MBI-226) was never approved, and no development has been reported in recent years. There is no legal route to obtain it as a medicine.
- Approval statusInvestigational
- RouteOn the skin (topical gel)
- Checked21 October 2026
- DoseFrom published clinical trials. Not approved by a regulator for this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesFDA GSRS substance record, omiganan pentahydrochloride (UNII LX2P9RD54V)FDA GSRS substance record, omiganan (UNII 618SLL9VBS)Micrologix Biotech, annual report for fiscal 2003 (Form 20-F)Micrologix Biotech, Form 6-K (December 2003)ClinicalTrials.gov, CLIRS posted results (NCT00231153)Cadence Pharmaceuticals, Form 8-K (March 2009)Cadence Pharmaceuticals, FDA agreement on increased enrollment (July 30, 2007)ClinicalTrials.gov, rosacea phase 3 posted results (NCT02547441)ClinicalTrials.gov, rosacea phase 3 posted results (NCT02576860)EU Clinical Trials Register, 2015-002919-15Rijsbergen M et al., British Journal of Clinical Pharmacology 2020;86:2133-2143Niemeyer-van der Kolk T et al., Clinical and Translational Science 2020;13:994-1003Rousel J et al., International Journal of Molecular Sciences 2023;24:14315Biofrontera, acquisition of Cutanea Life Sciences (2019)
What has happened recently
Never approved anywhere, and no marketing application was filed: Cadence said the CLIRS data did not support one. Micrologix Biotech of Vancouver licensed antimicrobial peptide technology from the University of British Columbia in April 1993, and after a phase 1 study finished in April 1999, the FDA granted Fast Track status to MBI 226 for preventing catheter-related bloodstream infections. Fujisawa Healthcare licensed North American rights in July 2002 ($1 million upfront and up to $20 million in development milestones); after the first phase 3 missed its primary endpoint in 2003, Micrologix took back all rights from Fujisawa in January 2004. Micrologix licensed North American and European rights to Cadence Pharmaceuticals (then called Strata) in July 2004, was renamed Migenix that September, and licensed worldwide dermatology rights to Cutanea Life Sciences in December 2005. Cadence ran CLIRS as Omigard (CPI-226) under an FDA Special Protocol Assessment and discontinued the product on March 12, 2009, after it missed its primary endpoint; Migenix later became BioWest Therapeutics, the sponsor now listed on the first trial's registry record. Maruho of Osaka bought Cutanea in February 2012 and kept research and development rights when it sold Cutanea to Biofrontera on March 25, 2019, and Maruho is now the registry sponsor of the CLS001 trials. The last trial, in seborrheic dermatitis, ran from November 2019 to January 2022 and was published in 2023; no trial has been registered since 2018, and no end to the dermatology program has been announced.
You can compare this against the whole library, or read how to check a seller.
What else is like Omiganan (MBI-226)?
Others in Immune support, side by side.If you're weighing Omiganan (MBI-226), it's worth reading P140 (forigerimod), Pegcetacoplan (Empaveli, Syfovre), and Pegtarazimod (RLS-0071) in the same class.
A short, tryptophan- and arginine-rich peptide gel that disrupts microbial membranes. Two catheter-site phase 3 trials missed their primary endpoints, and its two rosacea phase 3 trials split, one positive and one negative.
- Dose
- 1% gel at catheter sites, 1.6% gel on rosacea (phase 3 trials)
- How often
- Each dressing change (catheters) or once daily (rosacea)
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
Blocks complement at its central protein, C3. Twice-weekly infusions for PNH and kidney disease; eye injections every one to two months for geographic atrophy.
- Dose
- 1,080 mg twice weekly under the skin; 15 mg into the eye every 25 to 60 days
- How often
- Twice weekly (Empaveli); every 25 to 60 days (Syfovre)
A 15-residue peptide with a short PEG tail that stops the classical complement pathway at its first step and blunts neutrophil damage. Patient data so far are small and early.
- Dose
- 10 mg/kg IV every 8 hours (phase 2 trials)
- How often
- Every 8 hours for 3 to 14 days (trials)
Guides for this compound
- 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.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
- FDA GSRS substance record, omiganan pentahydrochloride (UNII LX2P9RD54V)(2026)Sequence ILRWPWWPWRRK, all L residues, C-terminal lysinamide; hydrochloride 1 to 5; CAS 269062-93-3.
- FDA GSRS substance record, omiganan (UNII 618SLL9VBS)(2026)INN omiganan; C90H127N27O12, MW 1779.15; CAS 204248-78-2.
- Micrologix Biotech, annual report for fiscal 2003 (Form 20-F)(2003)Fast Track granted after a phase 1 study finished in April 1999; first phase 3, 1,452 enrolled and 1,392 analyzed; Fujisawa license terms; MBI 594AN uses the same active ingredient as MBI 226.
- Micrologix Biotech, Form 6-K (December 2003)(2003)First phase 3: bloodstream infection 2.2% against 2.6% (p=0.966), colonization 31% against 40%, local site infection 3.5% against 6.9%; about 2% minor treatment-related events.
- ClinicalTrials.gov, CLIRS posted results (NCT00231153)(2009)1,859 randomized: local catheter-site infection 6.3% against 8.6% (p=0.082); confirmed site infection 3.9% against 7.6%; colonization 43.7% against 55.1%.
- Cadence Pharmaceuticals, Form 8-K (March 2009)(2009)CLIRS missed its primary endpoint; Omigard discontinued March 12, 2009; data did not support an NDA.
- Cadence Pharmaceuticals, FDA agreement on increased enrollment (July 30, 2007)(2007)Special Protocol Assessment; enrollment raised from 1,250 to 1,850; stricter re-analysis of the first phase 3 gave 3.5% against 6.1%.
- ClinicalTrials.gov, rosacea phase 3 posted results (NCT02547441)(2022)463 randomized: inflammatory lesions -18.1 against -13.5 (p=0.043); 2-grade improvement 26.3% against 16.9% (p=0.019).
- ClinicalTrials.gov, rosacea phase 3 posted results (NCT02576860)(2022)263 randomized: -19.8 against -20.9 (p=0.799); 24.6% against 25.6% (p=0.858).
- EU Clinical Trials Register, 2015-002919-15(2015)Rosacea phase 3 gel strength 1.6% w/w, once daily.
- Rijsbergen M et al., British Journal of Clinical Pharmacology 2020;86:2133-2143(2020)Anogenital warts (24) and vulvar HSIL (12): no clinical benefit; 2.5% gel; undetectable in all blood samples (taken in the vulvar HSIL trial only).
- Niemeyer-van der Kolk T et al., Clinical and Translational Science 2020;13:994-1003(2020)Atopic dermatitis, 36 randomized: target-lesion score -18.5% against vehicle at 2.5% (p=0.04); described as an indolicidin analog.
- Rousel J et al., International Journal of Molecular Sciences 2023;24:14315(2023)Seborrheic dermatitis, November 2019 to January 2022: omiganan 1.75% not efficacious against vehicle (p=0.14).
- Biofrontera, acquisition of Cutanea Life Sciences (2019)(2019)Maruho sold Cutanea to Biofrontera on March 25, 2019, keeping research and development rights.
Beyond these, 73 records are indexed. Browse the records