Ocular diseases

PDE6b Inherited Retinal Dystrophy (IRD)

PDE6b RP is an inherited retinal dystrophy that leads to blindness by midlife and is characterized by the progressive loss of photoreceptors, with or without the loss of retinal pigment epithelium cells.

It is caused by mutation of the PDE6b gene resulting in dysfunctional Rod PDE6, an enzyme found in rod outer segments that plays a key role in the phototransduction cascade in rods (the process by which light is converted into electrical signals). Dysfunction of the PDE6 protein, and in particular its PDE6ß subunit, ultimately leads to death of rod photoreceptor cells, then cone photoreceptor cells, leading to blindness.

Mutation of PDE6b is one of the most prevalent human mutations within autosomal recessive RP and accounts for 2-4% of RP cases.

There are currently no approved treatments for PDE6b RP.

HORA-PDE6b: A clinical stage AAV based gene therapy for treating PDE6b IRD

HORA-PDE6b is an AAV5 based gene therapy designed to deliver a full-length non-mutated copy of the functional human PDE6b gene into the subretinal space, where it rapidly induces robust transgene expression and synthesis of functional PDE6b proteins in photoreceptive rods and cones. By effectively providing these cells with a functional protein, HORA-PDE6b may significantly delay or halt retinal degeneration in PDE6ß-deficient patients.

HORA-PDE6b is currently in Phase I/II clinical trials.

A description of the protocol can be found on clinicaltrials.gov


eyeDNA and Théa Open Innovation (‘TOI’) are partners for the development and commercialization of HORA-PDE6b. eyeDNA is responsible for the global development of HORA-PDE6b and retains commercial rights to the product in the US, Japan, South Korea, China and other territories outside Europe. In Europe and certain other countries, HORA-PDE6b is being co-developed by Coave and Théa Open Innovation under a license and development agreement with exclusive rights granted to TOI to commercialize CTx-PDE6b in these territories.