Member Introduction: StemSight - A New Treatment for Corneal Blindness

The Tampere-based company StemSight is developing a groundbreaking treatment for a rare form of blindness—corneal blindness, which results from a deficiency of limbal stem cells that regenerate the surface of the eye. The goal is to restore vision for patients suffering from limbal stem cell deficiency, which can occur due to eye damage caused by injuries or accidents.

Currently, there is no available treatment for limbal stem cell deficiency. The development of this therapy began when Finnish corneal surgeons approached researchers in Tampere, hoping to find a treatment for patients affected by this rare eye condition.

Stem Cell Regeneration at the Core of the Treatment

StemSight’s treatment is based on induced pluripotent stem cells (iPSCs), which are similar to embryonic stem cells. These cells can be derived from sources such as skin or blood and reprogrammed to differentiate into various tissue types. StemSight uses there iPSCs to differentiate new limbal stem cells to restore the regenerative ability of the corneal surface.

Limbal stem cell deficiency can result from various causes, with chemical and burn injuries being the most common, as they damage the limbal stem cells located at the edges of the cornea. Normally, these stem cells continually proliferate and maintain a healthy corneal surface. However, if they are destroyed, the eye loses its ability to regenerate.

Without limbal stem cells, the eye attempts to repair itself incorrectly. The conjunctiva (the tissue surrounding the cornea) starts to grow over the cornea, forming an opaque tissue layer that impairs vision. This condition can also cause persistent eye pain, a sensation of having a foreign object in the eye, and increased light sensitivity.

StemSight’s treatment involves first surgically removing the damaged epithelial layer and scraping off the excess conjunctival tissue that has grown over the cornea. Next, StemSight's graft, composed of iPSC-derived limbal stem cells on a biomaterial carrier, is placed on the eye. The biomaterial resembles a soft contact lens, which degrades in the eye, leaving the cells to attach to the surface of the eye.

Once the stem cells attach to the cornea, they begin to replace the missing cell layer and restore the regenerative function of the corneal tissue. The aim is for these cells to remain in the eye long-term, maintaining corneal health and effectively restoring the patient’s vision.

Promising Results from Animal Trials

Animal trials have already shown promising results. Initial studies on mice and rats have yielded positive outcomes, and the next phase will expand testing to animals with larger eyes, such as pigs, whose corneal structure closely resembles that of humans. The first pilot studies in pigs will begin in April, with results expected by the end of the year.

To proceed to clinical trials, the safety of the treatment must also be confirmed. Additional studies are needed to ensure that the transplanted iPSC-derived cells do not migrate elsewhere in the body or form tumors. If funding allows the research to progress as planned, the first clinical trials are expected to begin in 2027.

Cost-Effectiveness

StemSight’s research is internationally unique. The only other known entity developing a similar treatment is an academic research group in Japan. StemSight’s competitive advantage lies in the scalability, reproducibility, and cost-effectiveness of its treatment.

In rare diseases, patient numbers are typically small and manageable, which means the therapeutic cells can be cultured using traditional cell culture techniques. Only about one million cells per patient are required for the treatment, making production significantly more cost-effective compared to therapies like CAR-T cell treatments, which require billions of cells.

Securing funding has not been easy, but the company has secured the resources to advance its research. The company recently announced a 2.3 million € funding round, and a Series A funding round is planned for 2026 to support the launch of clinical trials.

From Researcher to Entrepreneur

Laura Koivusalo, the CEO of StemSight, never saw herself as a traditional academic researcher. She was drawn to working in the research group because the project was highly intriguing and had a clear practical application. Early on, she convinced her professor that her ambitions lay beyond a conventional academic career.

As the research progressed towards commercialization, Koivusalo had the opportunity to join the team and contribute to building the company. Eventually, she found herself leading the company as CEO, with her former supervisors now working under her.

"I went from junior to boss," Laura laughs, adding that entrepreneurship has been the best decision she has made.

According to her, leading the company has been a continuous learning experience and has allowed her to work at the forefront of scientific innovation. While Finland has a strong biotech talent pool, there is still work to be done in commercialization and business development. International networking and collaboration are crucial for Finnish biotech companies to succeed globally.

Future Plans

The company is involved in the EU-funded KeratOPrinter project, which explores 3D bioprinting of the entire cornea using iPS cells. Additionally, StemSight plans to develop a second product focusing on corneal endothelial cell therapy, which would cater to a broader patient group.

Globally, nearly 13 million people are waiting for corneal transplants, highlighting the immense need for innovative treatments like StemSight’s.