StemSight gains patent for off-the-shelf limbal stem cell platform patent milestone for STE-101

According to a new announcement from StemSight, the Tampere, Finland-based regenerative medicine company has been granted a patent in Singapore and received notices of patent allowance in Canada and Japan for its proprietary stem cell manufacturing technology.¹ The patent family, titled "Method for Obtaining or Maintaining ABCG2-Positive Corneal Limbal Cells," covers the approach behind STE-101, the company's lead product for limbal stem cell deficiency (LSCD).¹ The milestone comes as StemSight prepares for an upcoming Series A financing round.¹

LSCD leaves many patients without effective treatment options, and existing cell-based approaches generally depend on limbal tissue harvested from a healthy donor eye or, in unilateral cases, from the patient's unaffected eye.² StemSight's platform instead generates limbal stem cells from induced pluripotent stem cells (iPSCs), which the company describes as a virtually unlimited starting material for standardized, scalable manufacturing.¹ This represents a departure from biopsy-dependent methods and is intended to support consistent, off-the-shelf production rather than bespoke, patient-specific preparations.¹

“Our proprietary technology enables scalable, standardized production of limbal stem cells, which we believe is essential to making regenerative therapies commercially viable and to making advanced regenerative treatments accessible to patients with few or no treatment options,” said Laura Koivusalo, CEO and co-founder of StemSight.

STE-101 consists of limbal stem cells derived from iPSCs using StemSight's patented differentiation process, which the company states can halt differentiation at a stage marked by expression of ABCG2, a cell-surface protein associated with early progenitor cells.¹ Because ABCG2 expression is typically transient during corneal epithelial differentiation, the proprietary method allows the company to expand this progenitor population at scale.¹ StemSight believes a high proportion of ABCG2-expressing cells may improve the product's ability to repopulate the limbal stem cell niche for durable corneal regeneration.¹ STE-101 is currently in late-stage preclinical development, with clinical trials in humans anticipated to begin in 2028.¹

Investment fuels next phase

The granted and allowed patents cover Singapore, Canada, and Japan, with corresponding applications still pending in Europe, the US, India, and South Korea.¹ StemSight has also advanced a separate patent family covering differentiation of corneal endothelial cell-like cells from pluripotent stem cells, now progressing toward approval in Japan, which the company says will support a future pipeline aimed at addressing the global shortage of donor corneal tissue.¹

Alongside the patent news, StemSight announced an investment from Life Science Invest (LSI Zeta), a Nordic network of life sciences business angels.¹ Kristian Klerfalk of LSI Zeta cited the company's science, team, and the unmet need in LSCD as reasons for the investment.¹ A first-in-human study from Osaka University, Osaka, Japan, has previously demonstrated transplantation of iPSC-derived corneal epithelial cell sheets in patients with LSCD, underscoring growing interest in iPSC-based approaches to corneal regeneration, though StemSight's manufacturing method and clinical positioning differ from that academic program.³

"With the first patent now granted and backing from a new investor secured, StemSight is entering an important growth phase as we prepare for Series A financing and future clinical development," said Ross Macdonald, chief commercial officer at StemSight, told Modern Retina.¹

Surgeons currently managing severe bilateral LSCD rely on techniques such as cultivated limbal epithelial transplantation, which carries an overall success rate of roughly 70% and donor-dependency limitations that an off-the-shelf iPSC-derived product could potentially address.⁴ StemSight's expanding intellectual property position, combined with new investment, positions the company to move STE-101 toward the clinical stage while building out additional ocular indications including corneal endothelial disease.¹

References

1. StemSight. StemSight granted patent for scalable stem cell technology targeting corneal blindness. Press release. June 16, 2026.
2. Ghareeb AE, Lake M, Figueiredo FC. Recent advances in stem cell therapy for limbal stem cell deficiency: a narrative review. Ophthalmol Ther. 2020;9:809–31. doi:10.1007/s40123-020-00305-2
3. Soma T, Oie Y, Takayanagi H, et al. Induced pluripotent stem-cell-derived corneal epithelium for transplant surgery: a single-arm, open-label, first-in-human interventional study in Japan. Lancet. 2024;404:1929-19.doi: 10.1016/S0140-6736(24)01764-1
4. Chen K, Soleimani M, Koganti R, Cheraqpour K, Habeel S, Djalilian AR. Cell-based therapies for limbal stem cell deficiency: a literature review. Ann Eye Sci. 2023;8. https://aes.amegroups.org/article/view/7277/html