PLEX technology - A lipid-and-polymer-based novel local drug delivery system - from concept to clinical practice

PLEX (Polymer-Lipid Encapsulation matriX) platform is a matrix made of layers of polymers and lipids that entraps a therapeutic drug between them to form a protected reservoir that enables an effective localized drug delivery at the target site. PLEX-based protected drug reservoir enable prolonged delivery of sensitive drugs over periods ranging from days to several months. The application of PLEX technology enables to optimize drug treatment regimens by predetermining release rates and durations, a rare combination of attributes. PLEX platform is suitable for the encapsulation of a variety of drug types ranging from small molecules to peptides, proteins including antibodies and siRNA. PLEX provides best in class therapy by combining pre-determined constant release rates over extended durations.

PolyPid is developing a family of product candidates consisting of PLEX encapsulating doxycycline, a widely-used antibiotic, which we refer to as our D-PLEX family. The PLEX matrices in this family are designed to mediate the release of doxycycline for up to four weeks. Our initial infection related targets are Surgical Site Infections (SSIs), the second most prevalent type of Healthcare Acquired Infections (HAIs). SSIs have substantial negative impact on patients’ clinical outcomes, they are the most common reason for unplanned readmission and thus pose a significant healthcare system burden.

D-PLEX`s ability to prevent SSI was clinically tested. Prevention of infection was seen even against antibiotic-resistant bacterial strains.

A mixture of D-PLEX and bone graft material was shown to be clinically highly potent in immediate bone grafting procedure in sever open tibia fractures, which is one of the most challenging contaminated condition in orthopedics. To date, no post-surgical infection or delayed hilling were associated with D-PLEX. Additionally, no product related adverse events were reported. Pharmacokinetics data demonstrated a very low plasma concentration of the antibiotic for over 30 days, and maximal concentration (C_max) of ~10 time less than the systemic administrated drug, suggesting constant and controlled release of the drug in humans.

Conclusion: Application of the prolonged-release formulation of doxycycline via D-PLEX products to surgical sites surgery is safe and has the potential to prevent SSI. Our preliminary studies show that D-PLEX products are both safe and effective.