The update was provided alongside news the group had applied to the US regulator to add a further nine people to its phase I/IIa clinical study.
The trial to do date has shown sufferers of retinitis pigmentosa receiving ReNeuron’s hRPC stem cell line have enjoyed “sustained clinically relevant improvements in visual acuity”.
The 12-month data reveal that people receiving surgery and the ReNeuron therapy could read seven more letters on a standard eye chart than those receiving surgery alone.
Those who received no treatment whatsoever saw a marginal deterioration in eyesight, while those who received the hRPC cells and no surgery saw a marked improvement in visual acuity, which peaked at six months at almost a 29-letter improvement, which receded to +12 letters at the nine-month stage.
ReNeuron chief executive Olav Hellebø said: "We remain greatly encouraged by the data from the phase I/IIa clinical study of our hRPC cell therapy candidate in patients with retinitis pigmentosa.
“The longer-term follow-up data are particularly noteworthy, demonstrating that the therapy appears to maintain its beneficial effects out to at least one-year post-treatment."
The company expects said it expects to present further data from the expanded clinical trial this year that would allow it to seek approval for a pivotal study in the first half of 2021.
Its programme in RP has been granted what’s called orphan drug designation in both Europe and America, which would give ReNeuron a greater period of exclusivity once the product is approved.
Its fast track designation from the US Food & Drug Administration means the hRPC treatment is eligible for accelerated approval and priority review process by the regulator.