BioWorld International Correspondent

PARIS - Neurotech SA initiated a Phase I clinical trial of NT-501, its lead encapsulated cell technology product for the treatment of retinitis pigmentosa.

NT-501 is an intraocular, polymer implant containing human retinal epithelial cells genetically modified to secrete ciliary neurotrophic factor (CNTF). It releases CNTF directly into the diseased retinal tissue for a sustained period of time.

Because intraocular delivery of CNTF has not been tried in patients before, the trial will test both the drug and the encapsulated cell technology (ECT) device in 10 pre-selected patients with late-stage retinitis pigmentosa (RP). The trial is being carried out at the National Eye Institute in Bethesda, Md., and if it confirms the safety of NT-501, a Phase II trial will be conducted to test the ability of the treatment to preserve vision in earlier-stage RP patients.

RP is an inherited degenerative eye disease for which there is no effective remedy. CNTF, a natural neuroprotective protein, has been shown in a variety of animal models to protect against the loss of photoreceptors. But delivery of therapeutic proteins into the eye is complicated by the fact that the blood-retina barrier rules out oral or intravenous administration and that repeated injections of CNTF into the eye are an impractical therapeutic option.

Neurotech now focuses exclusively on ophthalmology, having abandoned its programs in the field of central nervous system diseases. All of its research and development now takes place at the Lincoln, R.I. facility of its subsidiary, Neurotech USA Inc. It has only a skeleton staff at its head office in the Quinze-Vingts hospital in Paris, to which it relocated in January.