For surgeons treating PJI
Failed DAIR isn't a surgical problem.
It's a pharmacological one — and RETAIN is testing the first potential solution.
When PJI returns after surgery, it isn't because the debridement was inadequate. It's because biofilm and persister bacteria remain on the implant surface, where systemic antibiotics cannot reach them. RETAIN is the first Phase 2/3 trial to test a potential treatment for that residual reservoir directly.
01The clinical reality
Roughly half of DAIR patients fail. The literature has been consistent on this for two decades.
Across the published literature, 35–55% of patients undergoing debridement, antibiotics, and implant retention for PJI of the knee experience treatment failure. The failure isn't random. It tracks the one thing the operation cannot remove: the biofilm that is on the prosthetic surface.
Systemic antibiotics, even at maximal tolerated dose and duration, cannot penetrate the biofilm matrix in concentrations sufficient to clear the persister bacteria sheltered within it. Surgical debridement clears synovium and necrotic tissue. Modular exchange clears the polyethylene. Neither addresses biofilm on the implant.
If a patient comes back, you didn't fail. The pharmacology did.
02The RETAIN approach
PLG0206 — target the biofilm directly.
Pharmacological, not just surgical
Can biofilm be destroyed?
PLG0206 is a first-in-class investigational anti-biofilm peptide engineered to do what antibiotics cannot: penetrate the biofilm matrix on prosthetic surfaces and eradicate the persister bacteria protected within it — applied locally as an irrigation solution, at the source.
- Anti-biofilm
Penetrates and disrupts biofilm on prosthetic surfaces, killing bacteria that systemic antibiotics cannot reach.
- Broad-spectrum
Bactericidal activity against a wide range of gram-positive and gram-negative organisms, including MDR pathogens such as MRSA.
- Rapid-acting
- Potent anti-biofilm activity in preclinical models.
- Locally delivered
Administered as an intraoperative irrigation solution with limited observed systemic exposure.
- Adjunct to SoC
Added on top of the existing DAIR approach and postoperative antibiotic regimen; no change to surgical workflow.
- Safety profile
Evaluated at >100× systemic exposure in a Phase 1 clinical trial with no safety signals; studied in Phase 1b (n=14) PJI patients undergoing DAIR after TKA.
PLG0206 vs. systemic antibiotics at the biofilm interface.
A dashed outline indicates membrane disruption (bacterium killed).
03The trial
A landmark pivotal trial — now enrolling.
RETAIN is a randomized, double-blind, placebo-controlled, multi-center Phase 2/3 registration trial evaluating PLG0206 as an adjunct to standard-of-care DAIR for the treatment of PJI following total knee arthroplasty. The primary endpoint is treatment failure through 12 months.
Placebo control in a surgical PJI trial is uncommon. Most studies in this space have been single-arm or non-comparative. RETAIN is designed to produce evidence at the standard the field has been waiting for.
Full study details: ClinicalTrials.gov — NCT07214311
RETAIN builds on encouraging Phase 1b data: 1 of 13 PLG0206-treated patients in this open-label, non-comparative trial had a recurrence of infection through 12 months — a 7% failure rate, against the 35–55% benchmark from the literature.
Phase 1b data: ClinicalTrials.gov — NCT05137314. Phase 1b was open-label and non-comparative; cross-trial comparisons should be interpreted accordingly. PLG0206 is investigational.
04Patient eligibility at a glance
Screen a patient in fifteen seconds.
Eligible if
3 key criteriaThis study may be appropriate if your patient:
- Is between 18 and 79 years of age
- Has PJI following total knee arthroplasty (TKA)
- Is DAIR-eligible with a well-fixed prosthesis — surgeon is planning debridement with exchange of modular components
Not eligible if
4 key criteriaThis study is likely not appropriate if your patient:
- Has a history of prior PJI in the index joint
- Has had two or more prior revisions of the index joint
- Has suspected fungal PJI
- Requires long-term (>6 months) antibiotic therapy
Full inclusion and exclusion criteria: ClinicalTrials.gov — NCT07214311
05What we're asking
You don't need a patient today.
If RETAIN comes to mind in three weeks when a PJI patient walks into your clinic, this page has done its job. Bookmark it, forward it to a coordinator, and come back when the moment arrives. Two paths are ready for you when it does.
Path A · Now
I have a patient to refer.
A patient with confirmed or suspected PJI of the knee, planned for DAIR. Use the eligibility screen above; our clinical team prioritizes time-sensitive referrals. No patient-identifying information is required.
Path B · Future
I'd like to refer in the future.
We'll walk you through the referral process and what collaboration with the nearest participating center looks like. Submit your information; our clinical team will follow up at your convenience.
Request follow-up contact and information
Do not include patient-identifying information: This page does not accept protected health information. The intake form is for clinician-side contact details only; do not include patient identifiers in the referral message at this stage.
About your information: We collect your name, email address, phone number, organization, and postal code so that we can respond to your inquiry about RETAIN, discuss potential patient referrals, and, where appropriate, introduce you to the relevant RETAIN clinical trial contact, site, sponsor, or study team member for referral coordination. We use this information only for these RETAIN-related purposes and related administrative, compliance, and security purposes. We do not sell this information or share it for cross-context behavioral advertising. Do not include patient-identifying or health information in this form. See our privacy notice for more information about who controls your information, what we collect, our legal bases, who we share it with, how long we keep it, international transfers where relevant, and how to exercise your rights. To submit an access, correction, deletion, or other privacy request, use the privacy request form.
06RETAIN sites
RETAIN sites
- Boston Trial Center — Boston, MA
- Manhattan Orthopedic Trial Site — New York, NY
- Cincinnati Orthopedic Research Center — Cincinnati, OH
- Chicago Joint Infection Trial Site — Chicago, IL
- Central London Trial Site — London, England
- Manchester Trial Center — Manchester, England
- Birmingham Joint Infection Research Site — Birmingham, England
- Glasgow Orthopedic Trial Site — Glasgow, Scotland
- Sydney Trial Center — Sydney, NSW
- Melbourne Orthopedic Trial Site — Melbourne, VIC
- Brisbane Joint Infection Research Site — Brisbane, QLD
- Perth Orthopedic Trial Center — Perth, WA
- Active sites
- Planned sites