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Piano Player


PAX Therapeutics is a preclinical-stage gene delivery company relentlessly focused on bringing gene delivery out of the lab and into the clinical settings for patients with tendon and ligament injury.

Our initial product candidate, PAX-001, is our proprietary gene therapy currently in development for the treatment of flexor tendon injuries of the hand.

Anchor 1


PAX-001 is our proprietary vector- a cutting edge, yet proven gene delivery technology for hyper-localized production of VEGF, a growth factor that stimulates the production of Type 1 collagen.  The vector is AAV-2 which has been approved for use in children for another disease, and is in widespread clinical trials for other diseases.

HUMANS: This anticipated results based on the best pre-clinical animal model are faster stronger healing of the tendon following repair surgery for humans resulting in: 1) a more rapid ability to start using the joint, 2) resulting in less muscle wasting, 3) fewer re-ruptures, 4) fewer adhesions/scarring, 5) yielding better joint mobility and decreased pain.

HORSES: Current therapies are so unproven that a significant proportion of horses are euthanized after injury. PAX-001 results in the production of Type 1 collagen instead of Type 3 collagen which means that the typical process or remodeling from Type 3 to Type 1 collagen will not be needed resulting in faster healing. Given the structure of the key equine tendons involved, the intent is for non-surgical injection under ultrasound guidance. 

Lacrosse Players
Anchor 2
Training of Foals


PAX-001 is easily delivered by injection during repair surgery in humans and by Ultrasound-guided injection through the skin in horses. While our first application will be for repair of ruptured hand tendons, we anticipate expanding to non-surgical injection for human partial tendon tears and ligament injuries.

Anchor 3


PAX-001 is completing IND-enabling GLP studies along with dose-range finding studies, as the GLP material is more potent than the previous lab-made vector. We are on track to file an IND for initiating clinical trials in 1H2025. A human study has been initiated at Yale University to establish the exact post-operative protocols and measurements following standard-of-care surgical repair of hand flexor tendon transections in humans. This will provide comparative data for the PAX-001 initial human trial so that it will be a Phase 1/1B study providing indications of efficacy in addition to safety, which is typically the only readout of a Phase 1 study. 

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