A Stem Cell Therapy Resembling a Contact Lens Hopes To Cure Blindness

We are developing off-the-shelf replacements for lost or damaged cells in the eye to restore sight.

We are first focusing on a rare form of corneal blindness, called limbal stem cell deficiency, for which most patients currently have no existing treatment options. Limbal stem cells are the cells that constantly renew the surface layer of our cornea. In limbal stem cell deficiency, these cells have been destroyed by injury or disease, and the corneal surface begins to get clouded over by blood vessels and the surrounding tissue. We are hoping to provide a one-time treatment for these patients. In the future, we hope to apply the same tools and technologies to other areas of unmet need in blindness.

iPSCs are cells that can produce unlimited copies of themselves and can be guided to make any cell type found in the human body. We can specifically guide these iPSCs to become the cell type that we need to replace on the cornea – and that is part of our unique technology. In addition to the cells, we also need to have the means to accurately deliver them to the desired location. This is especially challenging in the case of limbal stem cell deficiency, where the cells must be delivered on the surface of the eye.

We have developed a biomaterial carrier, which we use to implant our cells. The carrier resembles a flexible contact lens, and it degrades after implantation. We believe that this approach is crucial for ensuring both effective delivery of the cells to the desired location, and increasing safety, as the cells are not going to off-target locations (which could happen with injection-based approaches). 

Corneal donor shortage is a global problem, with about 70 times more patients than there are donors. In limbal stem cell deficiency, the cadaveric donor corneas cannot even be used as a source of cells, as they do not contain the necessary viable limbal stem cells. For existing cell therapy approaches in limbal stem cell deficiency, cells have been extracted from the patient’s healthy eye and later transplanted to the affected eye. However, more than half of the patients are affected by the disease in both eyes, so they don’t have any treatment options.

Using a single source of iPSCs, we can produce our therapeutic cells in large batches, which we can then perform rigorous quality testing and freeze for later use. This shortens the time for treatment and reduces the manufacturing cost of the therapy. 

Before pursuing clinical trials, we must complete studies showing the efficacy and safety of the therapy. For efficacy, we have already established the feasibility of the therapy in rodents, but now we are verifying the results in a larger-eyed animal model. So, we are using a minipig model, where the cornea anatomy and eye size more closely resemble humans.

For safety, we need to establish that the cells don’t travel beyond the eye after implantation and that they don’t form unintentional tissue growth. The preparation for the clinical trial also takes time, from selecting trial sites to patient selection. Fortunately, our therapy is intended to have a very broad treatment window, so we hope to bring relief to many patients who might have suffered from limbal stem cell deficiency for years.