Phoenix Tissue Repair is advancing a novel treatment for Recessive Dystrophic Epidermolysis Bullosa (RDEB), a rare skin disease resulting from a deficiency of human collagen type VII.


Collagen is an essential component of human skin and connective tissues. More than two-dozen types of collagen exist in the body, each one playing its own distinct and important role. Collagen type VII functions as nature’s Velcro, forming anchoring fibrils that secure the skin’s protective outer layer, the epidermis, to the thick under-layer known as the dermis. Mutations in the gene that encodes collagen type VII can disrupt its ability to anchor the epidermis, resulting in a genetic disease called Dystrophic Epidermolysis Bullosa (DEB). DEB is characterized clinically by blister formation from mechanical trauma, frequently on the skin, but in severe forms, blisters can form throughout the body including in the mouth, on the external surface of the eye and on tissue lining the respiratory, gastrointestinal and genitourinary tracts. In some forms of the disease, disfiguring scars and disabling musculoskeletal deformities occur.

Two forms of the disease exist, based on how it is inherited. In the United States, the recessive form of DEB has a prevalence of between 3.5 and 20.4 affected patients per million people.

Recessive dystrophic epidermolysis bullosa or RDEB is a severe form of EB and, in addition to the blistering seen with other forms of the disease, manifests systemically with symptoms including malnutrition, anemia, esophageal strictures, growth retardation, corneal abrasions and fusion of the fingers and toes.

There is no cure for RDEB, and management of the disorder is complex, with treatment goals focused on managing blisters, controlling infection and the prevention of complications.


In patients with recessive dystrophic epidermolysis bullosa (RDEB), the epidermis can separate from the dermis. Even minor friction or trauma can cause debilitating blistering, tearing and scarring of the skin, along with severe pain and itching. The internal skin lining the mouth and throat are affected, disrupting patients’ ability to eat. Many die prematurely from aggressive squamous cell carcinoma, a common complication of DEB. These patients have no treatment options beyond daily wound care, pain management and protective bandaging. The epidermolysis bullosa patient community has done extraordinary work to spread awareness of the unmet medical need that patients face.

Phoenix Tissue Repair is working to create a first-ever systemic treatment for RDEB by replacing the collagen proteins (C7) at the root of the disease. In the first quarter of 2022, we completed a Phase 2 clinical trial of PTR-01, a recombinant version of the human protein collagen type VII (rC7) in adult patients with recessive dystrophic epidermolysis bullosa (RDEB). In this trial, we are evaluating safety and tolerability of PTR-01, as well as clinical proof of concept in RDEB including on wound healing and other efficacy endpoints. For more information about this trial, visit the posting on, or contact us at

About PTR-01

Phoenix Tissue Repair is advancing an investigational therapy known as PTR-01, a systemic recombinant collagen type VII (rC7) for the treatment of Recessive Dystrophic Epidermolysis Bullosa. rC7 is a potentially disease-modifying drug that is delivered intravenously to patients, replacing defective collagen type VII with healthy collagen at the sites where it is needed both internally and externally. PTR-001 is currently in clinical studies, with a Phase 2 study initiated in October of 2020.

Phoenix Tissue Repair acquired worldwide rights to PTR-01 from Shire Plc in 2017 and has initiated its first clinical trial (PTR-01-001). Preclinical studies of PTR-01 have shown that it selectively anchors in the skin and other tissues affected by an absence of collagen type VII. In four animal models of the disease, intravenous injections of PTR-01 promoted healing of DEB wounds. These experiments have shown improvements in tissue structure, disease presentation and survival, indicating a restoration of natural skin architecture. For more information, please contact us at


Board of Directors

About Us

Phoenix Tissue Repair is passionate about bringing forth a safe and effective drug for patients with Recessive Dystrophic Epidermolysis Bullosa (RDEB), a rare genetic disease affecting the skin and other organs.

Our dedicated team is working to develop a systemic treatment option that will provide appropriate replacement of the deficient collagen type VII protein to the patients’ skin and other tissues affected by this devastating disease. Investigational drug PTR-01 represents the only therapy in development with the potential to solve systemic manifestations of RDEB as well as the more visible skin-related aspects of the disease.


BridgeBio is a team of experienced drug discoverers, developers and innovators working to create life-altering medicines that target well-characterized genetic diseases at their source. BridgeBio was founded in 2015 to identify and advance transformative medicines to treat patients who suffer from Mendelian diseases, which are diseases that arise from defects in a single gene, and cancers with clear genetic drivers. BridgeBio’s pipeline of over 20 development programs includes product candidates ranging from early discovery to late-stage development.


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