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Update on PTR-01 trial phase 2 for EB

Rapid and durable wound healing and decrease in pain for RDEB patients: data of a phase 2 protein replacement trial (PTR-01) shows first positive results.

The study is based on a protein replacement therapy, which could correct the symptoms of recessive dystrophic EB (RDEB) in the long term. Patients with severe RDEB lack the collagen VII protein necessary for the cohesion of the skin layers due to an inherited mutation in the collagen 7 gene. Recently, first interesting results of the phase 2 trial were published. The approach is exciting for EB patients worldwide because the missing protein is systemically administered by intravenous injection.

It is not yet clear whether the therapy will actually work in the long term. Initial data show that after treatment, some patients retain the inserted collagen VII for up to three months. Some patients achieved a reduction of wounds as well as a clear pain relief in the course of the phase 2 study. In other patients, this success remained rather limited. In principle, the therapy approach is very interesting due to its systemic application. Phoenix Tissue Repair has initiated a Phase 2 extension study.

Summary of the data presented by BridgeBio Pharma affiliate Phoenix Tissue Repair

  • PTR-01 was well-tolerated over a four-month treatment period in RDEB patients.
  • Treatment led to rapid, consistent and durable wound healing as observed in reduction of wound surface area and clinican-reported assessment.
  • All patients that completed the study reported a decrease in pain over the course of treatment with PTR-01.

Details about the trial

PTR-01 is an intravenously-administered recombinant collagen VII (rC7) protein replacement therapy, in patients with recessive dystrophic epidermolysis bullosa (RDEB). The Phase 2, open-label study was designed to examine the effect of PTR-01 on wound healing as well as other endpoints, and to evaluate the long-term safety and tolerability of the drug candidate. The data shared at the 2022 SID Annual Meeting demonstrated that PTR-01 was well tolerated when given once per week for 4 weeks and then every other week for 14 weeks.

Phoenix Tissue Repair acquired worldwide rights to PTR-01 in 2017. Preclinical studies of PTR-01 have demonstrated C7 staining in basement membranes with de novo anchoring fibril formation and improved survival in models of RDEB.

PTR-01 has been granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency.

Read full press release.


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