ViGeneron GmbH has received Rare Pediatric Disease Designation (RPDD) from the FDA for VG901, its retinitis pigmentosa (RP)-targeted gene therapy candidate.
And as a bonus: The company was also granted approval for a new component in its ongoing clinical trial evaluating VG901 (but more on that later).
First, a debrief on this designation.
So we’re all on the same page: A RPDD is granted by the FDA for drugs under development for rare childhood diseases (affecting patients under the age of 18, such as RP) when a few key criteria have been met.
- See those criteria here.
A key advantage of this: ViGeneron now has the potential to receive a Priority Review Voucher (PRV) following its therapeutic’s marketing approval.
- Even further: This PRV would accelerate the FDA review process—cutting it down to just six months—and would be transferrable to another candidate in ViGeneron’s pipeline.
Now let’s get familiar with ViGeneron.
Headquartered in Munich, Germany, the privately-owned gene therapy company was founded in 2017 as a spin-off of the Ludwig-Maximilians-University Munich.
Its focus: Developing two inherited retinal disease (IRD) gene therapy programs via three proprietary and viral vector-based gene therapy platforms. The pipeline:
- VG901 (in clinical development for RP)
- Technology platform: vgAAV
- Our topic of discussion
- Technology platform: vgAAV
- VG801 (in clinical development for the most common IRD)
- Technology platform: vgAAV + REVeRT
Also in the preliminary stages is an undisclosed novel non-vascular endothelial growth factor (VEGF) candidate for age-related macular degeneration (AMD).
Circle back to those platforms.
Based on adeno-associated virus (AAV) vectors, each is designed to resolve two key limitations associated with current AAV-based gene therapies:
- Limited DNA uptake capacity (preventing treatment of large genes)
- Limited ability to cross biological barriers (requiring local delivery and, as a result, restricts administration routes)
See all three platforms, including the AAV Transactivation platform.
And which platform do we want to focus on?
The vgAAV vector platform.
- Take note: “vgAAVs” are described as “uniquely engineered” AAV capsids with novel properties that can “efficiently transduce target cells” as well as “overcome biological barriers and enable novel, less invasive routes of administration.”
- Compared to conventional treatments These engineered capsids can reportedly be transduced via intravitreal (IVT) injection and support lateral spreading beyond the bleb.
In this platform, vgAAV capsids are designed to:
- Efficiently transduce target cells
- Overcome biological barriers
- Enable novel, less invasive routes of administration
- Easily be produced in high yields
The potential of these: Currently only used in ophthalmology, vgAAVs could be widely used for other serotypes and tissues, ViGeneron reported—including the central nervous and cardio-metabolic system.
Now let’s discuss this RP candidate.
Already granted Orphan Drug Designation (ODD), ViGeneron refers to VG901 as a “first-in-class and only clinical-stage gene therapy to treat CNGA1-associated RP.”
- To note: Mutations in the CNGA1 gene are known to cause an estimated 2% to 8% cases of autosomal recessive RP (arRP) across the globe.
How VG901 works: The therapeutic incorporates vgAAV to deliver the CNGA1 gene to retinal photoreceptors via IVT injection.
And its clinical journey thus far?
Up to now, VG901 underwent clinical evaluation in vivo, demonstrating functionality by delivering the CNGA1 gene in a mouse model.
Plus: A good laboratory practice (GLP) safety study reportedly confirmed the therapeutic’s safety, durable expression, and sustained tolerability following a six-month observation period.
How about a phase 1 trial?
Funny you should mention that … VG901 is currently in a phase 1b trial (NCT06291935) in which its safety and preliminary efficacy (following one IVT injection) are being observed in two cohorts among six participants (aged 18+).
The goals of the study include determining:
- What is the best-tolerated dose, and are there any side effects—in particular, any inflammatory reactions post-drug administration?
- Are there any early signs of efficacy on visual function?
Go on …
In fact, ViGeneron’s second piece of news involved that study:
The independent Data Safety Monitoring Board unanimously approved dose escalation for this prospective, open-label, single-arm safety study, enabling a higher dose of VG901 to be administered.
- To note: Investigators from the ongoing study stated that “no dose-limiting adverse events” related to the therapeutic have been reported in its first-dose cohort thus far.
Sounds promising! So when might we see data?
With the study expected to conclude in December 2025, potentially in the very near future … so stay tuned!