Nanoscope Therapeutics Inc. released 3-year follow-up findings from a long-term extension of the phase 2b/3 RESTORE trial evaluating MCO-010, its optogenetic therapy, for the treatment of retinitis pigmentosa (RP).
The data was most recently presented during the 2025 American Academy of Ophthalmology (AAO) annual meeting in Orlando, Florida, earlier this month.
First, a look at optogenetics.
Optogenetics refers to a therapeutic approach that uses light to turn specific cells on or off—and is notable for its potential to treat retinal diseases via therapies that "functionalize retinal cells” to become light sensitive.
Now to this therapeutic.
To understand MCO-010, you’ll need some background on Nanoscope and its MCO-based science.
Next up: MCO-010.
Under clinical investigation for both RP and Stargardt disease—check out this recent positive phase 2 data from the STARLIGHT trial—MCO-010 (sonpiretigene isteparvovec) is a mutation-agnostic optogenetic gene therapy.
Specifically: It uses adeno-associated viral vector serotype 2 (AAV2) to deliver a multicharacteristic opsin (MCO) transgene via a single, in-office intravitreal (IVT) injection.
- The resulting effect: Transduction of bipolar cells to express photosensitive opsin and enhance vision in spite of photoreceptor loss.
How is this possible?
Via Nanoscope’s proprietary optogenetic technology, which makes highly dense bipolar retinal cells sensitive to light (photosensitive) while preserving the visual processing circuitry.
- How: By bypassing or supplementing dead photoreceptors.
Thanks to this tech, MCO-010 doesn’t need:
- Genetic testing (to determine patient eligibility)
- Surgical intervention
- Repeat dosing
As a bonus: See how else this gene-agnostic gene therapy differs from other RP treatments.
And in regards to this clinical data …
Our topic of conversation (an extension study’s 3-year findings) stems from that aforementioned phase 2b/3 RESTORE trial (NCT04945772).
Its purpose: To evaluate the efficacy of a single MCO-010 IVT injection via best-corrected visual acuity (BCVA) among RP patients.
And how did MCO-010 perform in that?
It met the study’s primary endpoint. Check out the full breakdown of data.
So this extension study was built off of those results, then?
Indeed. According to Nanscope, 152-week data from the long-term extension (dubbed REMAIN) demonstrated “durable and clinically meaningful vision improvements” following just one IVT injection of MCO-010.
- Further: The therapeutic’s favorable safety and tolerability profile was maintained through 3 years.
Give me some numbers.
Regarding MCO-010’s durable efficacy:
- Patients maintained an average BCVA gain from baseline of an estimated 0.3 LogMAR (equivalent to three lines or 15 letters on a standard Early Treatment Diabetic Retinopathy Scale [ETDRS] vision chart)
- BCVA-area under the curve (AUC) profiles for both the RESTORE and REMAIN extension trials demonstrated “fivefold greater vision gains” versus sham treatment
Any adverse events to report?
The company noted that no serious ocular adverse events (AEs) were observed among the treated patients.
As for long-term tolerability: One mild case of inflammation necessitated topical steroid treatment.
- And by Week 152, 14 of 15 treated patients did not require any ongoing inflammation management.
Nice! So what’s the significance of this data?
Per Nanoscope CEO Sulagna Bhattacharya, the results underscore MCO-010’s “lasting impact” on RP patients—and highlight the potential for the candidate as a one-time therapy for other retinal degenerative conditions.
And what’s next?
Did we mention Nanoscope is already in the process of submitting a Biologics License Application (BLA) for MCO-010?
Well… it is. That began over the summer, in June. See here for our coverage.
- Take note: Nanoscope noted that the new data from the REMAIN extension study will “form the clinical basis” of its BLA submission.
Back up a moment—What do you mean by “in the process”?
This is a rolling (ongoing) BLA submission—meaning that Nanoscope can submit sections of its application to the FDA as they become available (instead of all at once, as is usually the case).
- Nanoscope received this permission after the federal agency granted MCO-010 two key designations: Fast Track and Orphan Drug.
Also important to know: Due to those designations, MCO-010 also qualified for priority review—enabling an expanded FDA review (within 6 months) of the application.
So… when is this BLA submission expected to be complete?
As the company previously reported: early 2026.
And the big-picture potential: For MCO-010 to become the first gene-agnostic therapy to restore vision in legally-blind RP patients.