In another win for the gene therapy space, Dallas, Texas-based Nanoscope Therapeutics announced positive topline data in a Phase IIb trial of MCO-010 in advanced retinitis pigmentosa.

The 27-patient Phase IIb RESTORE trial (NCT04945772) met its primary efficacy endpoint of the Multi-Luminance Y-mobility Test (MLYMT), which measures patients’ ability to navigate between LEDs lights in a room of varying luminance. In the study, 18 patients received MCO-010 while 9 received a sham intravitreal injection.

Regulators consider a change of at least two luminance levels along the MLYMT to be clinically meaningful, as it indicates a patient can navigate through a dimmer room after treatment. In RESTORE, 16 out of 18 patients receiving MCO-010 met this efficacy threshold, compared to 4 of 9 patients receiving placebo (p<0.05).

MCO-010 also demonstrated a positive effect along the secondary endpoints of Multi-Luminance Shape Discrimination Test (MLSDT) and Best-Corrected Visual Acuity (BCVA), both of which test patients’ abilities to distinguish between objects like shapes or numbers from a distance.

As for safety, there were no reported serious adverse events (AEs) for MCO-010 treated patients. The most commonly reported treatment-emergent AEs across groups were anterior chamber cells, ocular hypertension, and conjunctival hemorrhage.

Nanoscope’s gene therapy delivers white opsin to ocular cells, which could restore white light-based vision and minimize chronic damage to retinal cells. In late February, the World Health Organization designated “sonpiretigene isteparvovec” as the International Nonproprietary Name for MCO-010.

Retinitis pigmentosa describes a group of rare, genetic disorders where the retina progressively degrades, causing impaired vision and blindness. MCO-010 has FDA Fast Track designation and orphan drug designations for both retinitis pigmentosa and the eye disorder Stargardt disease.

Progress in gene therapy space

The RESTORE trial of Nanoscope’s MCO-010 is one of five major gene therapy trials with major readouts expected in the first half of 2022.

Joining MCO-010 in the vision loss space is Applied Genetic Technologies’s Phase II/III study of AGTC-501 (NCT04850118), which has interim results expected in H1 2023. The study tests AGTC-501, also known as laruparetigene zovaparvovec, in X-linked retinitis pigmentosa caused by mutations in the RPGR gene.

As investment in late-stage gene therapies continues to rise, funding is pouring into the development of gene therapy delivery systems like adeno-associated viruses (AAVs). Meanwhile, 2023 could also see the first FDA approval for a CRISPR gene therapy.