Phase II Trial Demonstrates Vision Gains in Stargardt Disease With MCO-010

Nanoscope Therapeutics has announced the publication of positive results from the Phase II STARLIGHT clinical trial (NCT05417126) of MCO-010 (sonpiretigene isteparvovec) for the treatment of patients with Stargardt disease (SD).¹

Now published in eClinical Medicine, part of The Lancet Discovery Science, data from STARLIGHT show:²

• Across all participants, mean best-corrected visual acuity (BCVA) improved by 5.5 ETDRS letters without a wearable low-vision aid and by 9.0 letters with the aid at week 48.
• In patients with atrophy limited to the macula, mean improvement was 12.0 ETDRS letters without the aid and 32.0 letters with the aid.
• Some participants experienced vision gains as early as four weeks after treatment, with improvements sustained through week 48.
• MCO-010 was well tolerated, with no serious adverse events reported over the 48-week period.

First trial to demonstrate vision improvements in Stargardt disease

According to Nanoscope, STARLIGHT is the first and only trial to demonstrate vision improvements in patients with SD.

In a press release, Byron Lam, MD, Professor of Ophthalmology at Bascom Palmer Eye Institute, lead author and principal investigator of the STARLIGHT study, said: “While this was an open-label study, this is one of the first studies to demonstrate vision improvement in Stargardt disease patients. This is a remarkable finding as these patients typically experience irreversible central vision loss over their lifetimes. I am thrilled to be part of the upcoming Phase III trial of MCO-010 in Stargardt disease, helping advance this promising therapy towards potential approval.”

Study design and patient population

STARLIGHT was an open-label, 48-week study conducted at two sites in the United States. The trial evaluated the safety and efficacy of a single intravitreal injection of MCO-010 in the worse-seeing eye of patients with SD.

• Six adults (mean age 50 years, range 32–71; four males and two females) received 1.2×10¹¹ genome copies per eye.
• The primary outcome measures included incidence, nature, and severity of treatment-emergent and serious adverse events, intraocular inflammation, retinal thickness, BCVA, and lesion size.
• Secondary endpoints included changes in BCVA, vision-guided mobility, and shape determination accuracy.
• Exploratory endpoints included visual field perimetry and responses to the Michigan Retinal Degeneration Questionnaire.

In the press release, Samarendra Mohanty, PhD, president and chief scientific officer of Nanoscope, added: “We are grateful to the patients and investigators who participated in the trial. The results we have seen in STARLIGHT for SD patients reinforce the therapeutic potential of our gene-agnostic MCO-010 platform, building on positive outcomes in both Stargardt and retinitis pigmentosa populations.”

Next steps: Phase III STARGAZE trial

As mentioned by Lam, Nanoscope will be launching a Phase III, randomized, double-masked, sham-controlled trial, STARGAZE, to further evaluate MCO-010 in SD.

• The registrational study will enroll approximately 60 patients across multiple clinical centers.
• The primary endpoint is the change in BCVA measured with a standard vision chart compared to sham control.
• A key secondary endpoint will evaluate improvement in multi-luminance shape recognition.
• Top-line results are anticipated in 2027.

The initiation of STARGAZE follows a positive, End-of-Phase II meeting with the FDA. The agency offered support on further evaluation of MCO-010.³

In a press release from the time of when the meeting outcome was announced, Sulagna Bhattacharya, co-founder and chief executive officer of Nanoscope, said: “Patients suffering from Stargardt Macular Degeneration face a substantial disease burden with no restorative treatments presently available. Following the positive results from the Phase II STARLIGHT clinical trial, the outcome of this meeting strengthens our conviction to advance clinical development of MCO-010 in this indication. We appreciate the FDA’s guidance and look forward to finalizing preparation for the Phase III trial.”

References

1. Nanoscope Therapeutics Announces Publication of STARLIGHT Phase 2 Study Evaluating MCO-010 Gene-Agnostic Therapy in Patients with Stargardt Disease. News release. Nanoscope Therapeutics. August 14, 2025. Accessed August 15, 2025. https://nanostherapeutics.com/2025/08/14/nanoscope-therapeutics-announces-publication-of-starlight-phase-2-study-evaluating-mco-010-gene-agnostic-therapy-in-patients-with-stargardt-disease/

2. Lam, B. et al. Safety and efficacy of MCO-010 optogenetic therapy in patients with Stargardt disease in USA (STARLIGHT): an open-label multi-center Ph2 trial. eClinical Medicine. https://www.sciencedirect.com/science/article/pii/S2589537025003621 (2025)

3. Nanoscope Therapeutics Announces End-of-Phase 2 Meeting with U.S. FDA and Plan to Initiate a Phase 3 Clinical Trial of MCO-010 to Treat Stargardt Macular Degeneration. News release. Nanoscope Therapeutics. September 12, 2024. Accessed August 15, 2025. https://nanostherapeutics.com/2024/09/12/nanoscope-therapeutics-announces-end-of-phase-2-meeting-with-u-s-fda-and-plan-to-initiate-a-phase-3-clinical-trial-of-mco-010-to-treat-stargardt-macular-degeneration/