Kiora Pharma is Starting Human Trials of a Novel Treatment That Could Restore Vision In Patients With Inherited Blindness

Kiora Pharmaceuticals Inc. KPRX, a pharmaceutical company specializing in treating eye diseases, is moving its drug candidate KIO-301 into a Phase 1b study in the third quarter of this year.

The treatment could offer patients with retinitis pigmentosa (RP), a rare and incurable disease that causes progressive blindness, the chance to regain some of the sight lost to the disease. Here’s what the latest research on RP treatments has achieved so far and why Kiora believes KIO-301 could be a breakthrough that finally pushes the treatment landscape forward.

Retinitis Pigmentosa Is A Genetic Disease That Damages The Retina

Retinitis pigmentosa is an umbrella term for a cluster of genetic eye diseases that damage the retina, the light-sensitive layer of the eye. These diseases cause the photoreceptor cells on that layer to break down and die over time. The result: a slow onset of blindness that usually starts in childhood and eventually leads to a total or near-total blindness later in life. 

Developing a treatment for RP has been difficult because there are multiple genes involved in controlling the photoreceptor cells of the retina. If any of these genes is changed, it can cause the symptoms associated with RP, and it’s estimated that about 1 in 1,000 people carry a changed gene that could cause RP, though only about 1 in 3,500 will develop the condition.

To date, no cure exists and the only treatment options available are low vision aids and training programs that help people adapt to life with low or no vision. 

New Research Has Made Progress Toward Treating RP, But A Cure Still Eludes Patients

As researchers discover more about the underlying genetics of RP, four novel treatment approaches have emerged: gene augmentation therapy, cell replacement therapy, retinal implants, and small molecule intervention.

Gene Augmentation Therapy

Clinical-stage companies like MeiraGTx Holdings PLC MGTX, 4D Molecular Therapeutics FDMT and Coave Therapeutics (private) are investing in gene therapies that each target specific genes that have been linked to RP.

By delivering functional copies of those genes to the retina, the hope is that the newly introduced genes can help preserve or improve vision. However, it’s typically most effective when used in the early stages as it’s better at preserving existing vision than restoring lost vision.

Cell Replacement Therapy

Cell replacement therapy involves repopulating the retina with new photoreceptors generated from retinal progenitor cells (a kind of stem cell) transplanted into the eye. For example, Bayer AG BAYRY partnered with other biotechs and research centers last year to fund a stem cell transplant therapy to replace damaged and dying photoreceptors in the retinas of RP patients.

But as with other transplants, this treatment approach comes with the risk that the patient’s immune system will reject the donor cells. Even when cells aren’t rejected, transplanted cells have a low survival rate, meaning only a few of the new photoreceptor precursors actually get integrated into the patient’s retina.

Retinal Implants

Retinal implants are electronic devices that can act as a substitute for lost photoreceptors. The Orion Visual Cortical Prosthesis System from Vivani Medical Inc. VANI, for example, is an implant that bypasses the optic nerve and directly stimulates the visual cortex. The implant has a wireless receiver that picks up video captured by a small camera mounted on glasses and converts that into electrical impulses that are then sent to the visual cortex to be processed similarly to the way that cortex once processed signals sent from the eye.

Though still in clinical trials, patients who have received the implant so far have had some visual function restored. However, even in the best case scenario, it’s not a perfect solution. The artificial substitute for vision can improve the ability to detect shapes and movement — an important difference for RP patients with near-total blindness — but it doesn’t restore full sight to patients.

Kiora’s KIO-301 May Help Restore Lost Eyesight

Kiora’s KIO-301 is a small-molecule treatment that could potentially restore sight to people with RP. “Molecular photoswitches” that change shape in response to changing light levels are injected directly into the eye where they can convert downstream retinal cells, like retinal ganglion cells (RGCs) into light-sensitive cells that can act similarly to photoreceptors.

RGCs are normally the relay cells that take signals sent from healthy photoreceptors and pass them along to the brain to be “translated” into visual information. Without photoreceptor cells giving them signals, though, they become inactive. 

So KIO-301 aims to modify these inactive signaling cells by attaching the molecular photoswitches to them. With their new attachments, these downstream retinal cells would be able to pull double duty: sensing light and converting it into a signal to relay to the brain.

Because it works by attaching to RGCs, it has the potential to treat RP patients regardless of the specific gene mutation causing their vision loss as well as patients with age-related retinal degeneration, even in later stages of disease progression. It would also be a less invasive (and potentially more effective) procedure than retinal implants. 

Kiora received approval and has reported plans to begin enrolling patients in a Phase 1b study of KIO-301 this year, with the expectation of reporting rolling data on safety and efficacy before year end and into 1Q23. 

Click here for more information on Kiora Pharmaceuticals: https://redingtonvirtual.com/kprx-benzinga-1/

This post contains sponsored advertising content. This content is for informational purposes only and is not intended to be investing advice.

Featured photo provided by Brands&People on Unsplash