Biotechnology company Amarantus BioScience Holdings has reported positive data for Mesencephalic-Astrocyte-derived neurotrophic factor (MANF) in retinitis pigmentosa (RP), a degenerative disease.
According to the study, intravitreal injection of recombinant human MANF protein protects both rods and cones from retinal degeneration in an animal model of RP.
Amarantus CEO Gerald Commissiong said as the company continues to move its internal MANF programmes forward, related to mediating endoplasmic reticulum (ER) stress, the MANF therapeutic development franchise can now be expanded into ophthalmology.
"By identifying retinitis pigmentosa as an indication for MANF, we have identified a potentially reduced timeline to get MANF to commercialisation with a very substantial market opportunity," Commissiong said.
The study examined the neuroprotective effect of MANF on rod photoreceptors, recombinant human MANF (6µg) by intravitreally injecting to the left eyes of the transgenic rat S334ter rats (line 3) at PD9, and the right eyes were injected with PBS as controls.
MANF (6µg) was injected intravitreally to the left eyes of the transgenic rats at PD20, and the right eyes were injected with PBS as controls for the examination of the effect of MANF on cone photoreceptors. The eyes, collected at PD21, were examined under light microscopy.
Flat-mounted retinas, collected at PD30 and cone outer segments stained with Alexa 488 conjugated peanut agglutinin (PNA), were examined by confocal microscopy.
Rod photoreceptors were protected by MANF and three to four rows of nuclei in MANF-treated retinas remained in the outer nuclear layer (ONL), as compared to only one row of nuclei in PBS-treated fellow eyes.
Higher thickness of ONL was observed in MANF-treated retinas compared to that of PBS-treated retinas.
Amgen co-founder and current board member Dr Joseph Rubinfeld said: "The delivery of MANF directly to the eye in this indication will be local, potentially significantly reducing timelines to get this into the marketplace versus systemic applications."
Image: Fundus of patient with retinitis pigmentosa, mid stage (bone spicule-shaped pigment deposits are present in the mid periphery along with retinal atrophy, while the macula is preserved although with a peripheral ring of depigmentation. Photo: courtesy of Christian Hamel.