Zaloganan (PLG0206)_Dosage, benefits & legal status
Also known as PLG0206, WLBU2
A surgical rinse whose headline number was never an endpoint.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Zaloganan (PLG0206)?
Plain language first. The technical label stays, but it never stands alone.Overview
This is a man-made antibacterial peptide, built from scratch rather than copied from nature, and the way it is used is the most interesting thing about it. Instead of being injected and expected to travel through the blood, it is poured straight into an open knee joint as the last rinse before the surgeon closes, during an operation to rescue an infected knee replacement. That sidesteps the problem that has killed most peptide antibiotics, since a peptide that would be torn apart or cause trouble in the bloodstream only needs to work for a few minutes in a washed-out joint. The catch is that the success figure people repeat was never something the trials set out to measure, and the company has described it three different ways.
Zaloganan is a fully engineered cationic antimicrobial peptide of 24 residues, RRWVRRVRRVWRRVVRVVRRWVRR, carrying a C-terminal amide, CAS 2759007-66-2, international nonproprietary name number 12764. It was not discovered in a human or an animal. The design began with an idealized twelve-residue amphipathic lytic base unit built from only arginine and valine. That unit was then joined head to tail as a tandem dimer and modified by substituting tryptophan at three positions on the hydrophobic face. Its structural lineage traces to the lentivirus lytic peptide 1 region of HIV-1 rather than to any human host defense peptide. In development it is used as a single intra-articular irrigation during surgery for periprosthetic joint infection, where the mechanism of interest is direct disruption of bacterial membranes and of established biofilm at high local concentration.
What it's used for
Investigational only, for infection of an artificial knee joint. It is given once during surgery as the final irrigation, in a trial setting. It is not approved anywhere and is not sold.
How does Zaloganan (PLG0206) work?
What it does in the body, and where.Most antimicrobial peptides fail for the same reason: they work in a dish and then cannot survive a bloodstream, or they damage the patient at the dose that kills the bacteria. This program is built around avoiding that problem rather than solving it.
- 01Designed, not discoveredThe starting point was an idealized twelve-residue lytic base unit using only two amino acids, arginine for positive charge and valine for bulk, arranged so that one face of the helix is charged and the other is hydrophobic. That unit was joined to a copy of itself to make a 24-residue tandem dimer, then three valines on the hydrophobic face were swapped for tryptophan. The structural idea traces back to a lytic region of HIV-1 rather than to any human defense peptide.
- 02Charge finds the membraneThirteen of the 24 residues are arginine, giving a strong positive charge that is drawn to the negatively charged outer surface of bacterial membranes. Human cell membranes carry much less negative charge on their outer face, and that difference is the usual basis for selectivity in this class. The three tryptophans help the peptide insert at the membrane interface rather than simply sitting on it.
- 03It tears the membrane instead of hitting a targetOnce inserted, the peptide disrupts membrane integrity directly rather than binding an enzyme or a receptor. That matters for resistance, since there is no single protein target to mutate, and it matters for biofilm, where conventional antibiotics struggle because the bacteria inside are metabolically quiet and most antibiotics need active cellular processes to work. A physical mechanism does not care whether the cell is dividing.
- 04The route is the whole strategyRather than asking the peptide to circulate, the program pours it into a joint that has been opened and washed during a debridement procedure, as the last rinse before closing. For a few minutes the local concentration can be far above anything achievable in blood, and afterward the peptide is removed with the fluid. Half-life, plasma protein binding and systemic toxicity all become much smaller questions than they would be for an infusion.
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.
The number that was never an endpoint
none- No dataThe phase 1b registry entry lists safety as the primary outcome and no secondary outcomes, so the 93% success figure was never a registered endpoint.
- No dataCompany statements describe the same cohort three ways: 13 of 14 at 180 days in September 2023, 13 of 14 at 12 months in October 2025, and 1 of 13 failing by 12 months in March 2026.
- No dataAll of it is press-release material. No peer-reviewed efficacy result exists for this compound.
The sequence disagreement
none- lab-analysisFDA's substance registry gives RRWVRRVRRVWRRVVRVVRRWVRR, with tryptophan at positions 3, 11 and 21.
- No dataMost of the literature, including a review from the company itself, prints a version with the second tryptophan at position 10. The company's own PLOS ONE figure disagrees with that review.
- lab-analysisBoth versions are 24 residues with identical composition, 13 arginine, 8 valine and 3 tryptophan, so composition cannot settle which is correct. The question remains formally unresolved.
What the phase 1 studies actually did
peer-reviewed-human- Human trialTwo separate phase 1 studies: an intravenous single ascending dose study in 48 healthy subjects from 0.05 to 1 mg/kg, and a 14-patient surgical irrigation study.
- No dataThe planned 2 and 3 mg/kg intravenous levels were never run, and no public document gives a reason.
- No dataPublished half-life figures conflict, 6.5 to 11.2 hours against 7.37 to 19.97 hours reported at a conference.
Where the molecule comes from
Early research- Lab studyBuilt from an idealized twelve-residue arginine and valine lytic base unit, joined as a tandem dimer, then given three tryptophan substitutions on the hydrophobic face.
- Lab studyThe structural lineage is a lytic region of HIV-1, not a human host defense peptide, so describing it as a natural antimicrobial peptide is wrong.
- No dataLaboratory catalog WLBU2 is sold as a free acid, while the clinical compound is amidated, so reagent material is not necessarily the same molecule.
The 93% success rate is the main problem. It comes from company press statements, not a trial: the phase 1b study registered safety as its primary outcome and listed no secondary outcomes, so efficacy was never an endpoint, and the company has described that same small cohort three different ways across three years. The second error is the sequence. FDA's substance registry places the second tryptophan at position 11, while most published sources, including a review written by the company, place it at position 10; both forms have identical composition, so the disagreement cannot be settled by composition and remains open. The third is calling it a natural or human antimicrobial peptide. It was engineered from an idealized arginine and valine base unit whose lineage runs to a lytic region of HIV-1. The fourth is listing breakthrough therapy designation among its FDA grants: it holds orphan drug, qualified infectious disease product and fast track status, not breakthrough. Last, the research peptide sold as WLBU2 is a free acid while the clinical compound is amidated.
The published record
Papers and trials about Zaloganan (PLG0206)
Searched: zaloganan, PLG0206, WLBU2.
Left out: antimicrobial peptide (an enormous class literature. This site already carries LL-37, pexiganan, omiganan, darobactin, teixobactin and others, each with its own slug); cationic peptide (a class descriptor covering most of that same literature); lytic base unit (the design concept behind a family of engineered peptides, not an identifier for this one); LLP1 (the lentivirus lytic peptide 1 region of HIV-1 that this molecule descends from structurally. Searching it returns HIV virology rather than anything about this compound); periprosthetic joint infection (a large orthopedic infection literature covering debridement, antibiotic spacers and revision surgery, not this drug); Peptilogics (a company name); biofilm (a very large microbiology literature; the row must stay anchored on the molecule).
20 papers tagged human · 10 not reviews or lab · 2 clinical trial publications
How the compound was given: 2 applied to skin · 7 injected · 2 by mouth or rectal · 40 route not stated in the abstract
Read from each paper's indexing terms and abstract, by rule. A paper that mentions a cream studied a cream, not necessarily the product being sold.
2 registered trials · none with posted results
Furthest stage reached: Phase 2, under way
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 Zaloganan (PLG0206)
Evidence
Investigational
Category
Immune support
Common vial
Varies
Half-life
Reported between about 6.5 and 20 hours in the vein studies, with sources disagreeing
How much, and do you cycle it?
The range, and whether you take breaks.A single intra-articular irrigation during the operation; the registry states no concentration, once, during the operation. Single intraoperative administration Trial dose
It is given once, during one operation, as the final irrigation. No repeat dosing or cycling scheme exists in the trial design.
How long does it stay in the body?
The half-life, and where the figure comes from.Reported between about 6.5 and 20 hours in the vein studies, with sources disagreeingHuman study
Two sources give different ranges for the same program, 6.5 to 11.2 hours in the journal report against 7.37 to 19.97 hours presented at a conference, and the full text is paywalled so the conflict could not be resolved. The figure matters less here than it would for most drugs: the lead program puts the peptide into an opened joint for the length of a rinse and then removes it with the fluid, so systemic persistence is not what the compound is being asked to do.
Source: Phase 1 single ascending dose study, Antimicrobial Agents and Chemotherapy 2022, volume 66, DOI 10.1128/aac.01441-21
You can compare this against the whole library to see where it sits.
How is it given?
Dosing context and source notes.Given in hospital from a prepared product, so there is nothing to mix.
Given once by the surgical team as the final irrigation step during the operation. The trial registry does not state a concentration or a volume, so no figure is given here.
How do you store it?
Before mixing, and after.Given in a hospital or trial clinic, so the pharmacy stores it.
Zaloganan (PLG0206) is prepared and given by hospital, clinic or trial staff, following the product label or the trial protocol. Some products like this arrive ready to use and others are mixed just before the dose, often with hours rather than weeks of shelf life once prepared. It is not a medicine people store at home.
What are the side effects and cautions?
Known cautions and warnings for this compound.Solubility, computed: 62% charged residues, 46% 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
- Any reading of the 93% success figure as a trial result: the phase 1b study registered safety as its primary outcome and listed no secondary outcomes at all
- Treating laboratory catalog WLBU2 as the same material, since the reagent form is sold as a free acid while the clinical compound is amidated
- Expecting this to behave like a systemic antibiotic, since the development route deliberately avoids the bloodstream
Stop and get help
- Signs of worsening joint infection after surgery, such as fever, spreading redness or wound drainage
- Any allergic reaction, including rash, swelling or difficulty breathing
Common effects
- Nothing established. The published safety experience covers 62 people across two small phase 1 studies.
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Zaloganan (PLG0206) approved?
And where the numbers on this page come from.No. Zaloganan (PLG0206) is not approved anywhere and is currently in company-run clinical trials. There is no legal route to obtain it outside a trial.
- Approval statusInvestigational
- RouteInto the joint during surgery, as the final irrigation
- Checked1 November 2026
- DoseFrom published clinical trials. Not approved by a regulator for this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesClinicalTrials.gov record NCT07214311, the RETAIN trialPLOS ONE, engineered peptide PLG0206 against a challenging targetAntimicrobial Agents and Chemotherapy, phase 1 single ascending dose studyAntibiotics, PLG0206 eliminates biofilmsAntimicrobial Agents and Chemotherapy, de novo generation of cationic antimicrobial peptidesFDA substance registration record for zaloganan
What has happened recently
FDA has granted orphan drug designation, dated September 9, 2020, qualified infectious disease product status, and fast track designation dated July 19, 2022. It has not received breakthrough therapy designation, despite that claim appearing in secondary coverage. The pivotal program is NCT07214311, called RETAIN, a phase 2/3 trial sponsored by Peptilogics that began February 3, 2026 and is recruiting, with 240 participants planned and primary completion estimated for September 2028. The design is stronger than most antimicrobial trials: triple-masked across participant, investigator and outcomes assessor, placebo-controlled against 0.9% sodium chloride, with the proportion of patients experiencing treatment failure through 12 months as the primary outcome and 17 secondary outcomes including anti-drug antibodies, plasma pharmacokinetics and the Oxford Knee Score. It runs at 21 sites across the United States and the United Kingdom, 16 and 5 respectively, with two further sites withdrawn before enrolling. A $78 million series B2 financing closed on October 16, 2025. Nothing is on sale: searches of the usual channels return laboratory reagent houses offering the research peptide and nothing offered as the clinical product.
You can compare this against the whole library, or read how to check a seller.
What else is like Zaloganan (PLG0206)?
Others in Immune support, side by side.If you're weighing Zaloganan (PLG0206), it's worth reading Zilucoplan (Zilbrysq), Glutathione, and Thymosin Alpha-1 in the same class.
A surgical rinse whose headline number was never an endpoint.
- Dose
- A single intra-articular irrigation during the operation; the registry states no concentration
- How often
- Once, during the operation
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- Dose
- 16.6, 23 or 32.4 mg daily, by body weight (label)
- How often
- Once daily
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- Dose
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- How often
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- Dose
- 1.6 mg per dose
- How often
- 2x per week
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.
- 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
- ClinicalTrials.gov record NCT07214311, the RETAIN trial(2026)Phase 2/3, sponsor Peptilogics, recruiting, start date February 3, 2026, estimated primary completion September 2028, 240 participants planned. Triple-masked across participant, investigator and outcomes assessor, with 0.9% sodium chloride as placebo. Inclusion requires knee periprosthetic joint infection and the intervention is a single intra-articular irrigation given as the final irrigation step during debridement, antibiotics and implant retention surgery. Primary outcome is the proportion of patients with treatment failure through 12 months, with 17 secondary outcomes including anti-drug antibodies, plasma Cmax, Tmax, half-life and AUC, and the Oxford Knee Score. 21 sites across 2 countries, 16 in the United States and 5 in the United Kingdom, with two sites withdrawn.
- PLOS ONE, engineered peptide PLG0206 against a challenging target(2022)Volume 17, article e0274815. The main published characterization of the compound. Its figure 1 gives a sequence that disagrees with the version reproduced in most of the later literature, including a review from the company itself, on the position of one tryptophan.
- Antimicrobial Agents and Chemotherapy, phase 1 single ascending dose study(2022)Volume 66. The intravenous single ascending dose study in 48 healthy subjects, from 0.05 to 1 mg/kg. The planned 2 and 3 mg/kg levels were not run. Reported half-life figures conflict with those presented at a conference, 6.5 to 11.2 hours against 7.37 to 19.97 hours, and the full text is paywalled so the discrepancy could not be resolved here.
- Antibiotics, PLG0206 eliminates biofilms(2021)Volume 11, article 41. A review from the company developing the compound. It is cited here for an unusual reason: it reproduces the tryptophan position that disagrees with the company's own PLOS ONE figure, so the sequence confusion is not confined to outside sources.
- Antimicrobial Agents and Chemotherapy, de novo generation of cationic antimicrobial peptides(2005)Volume 49, pages 316 to 322. The origin paper for the lytic base unit approach that produced this peptide, establishing that the molecule is an engineered construct rather than a natural product. The figure giving the base unit is an image, so the twelve-residue unit could not be transcribed from it directly.
- FDA substance registration record for zaloganan(2026)UNII HYE7ZLD2RQ, CAS 2759007-66-2. The systematic name ends in L-argininamide, establishing the C-terminal amide. The registry subunit sequence reads RRWVRRVRRVWRRVVRVVRRWVRR, placing tryptophan at positions 3, 11 and 21. The formula and molecular weight fields in this record are blank.
Beyond these, 52 records are indexed. Browse the records