Prof Ula Jurkunas in her lab. Credit: Mass Eye and Ear

A groundbreaking, experimental stem cell treatment for blinding cornea injuries resulted in a 92% success rate at 18 months.

Led by Massachusetts Eye and Ear in Boston, US, and published in Nature Communications, an expanded clinical trial found the new treatment was feasible and safe in 14 patients with limbal stem-cell deficiency (LSCD). The novel therapy, called cultivated autologous limbal epithelial cells (CALEC), removes stem cells from a healthy eye with a biopsy and expands them into a cellular tissue graft in a novel two- to three-week manufacturing process. This is then surgically transplanted into the eye with the damaged cornea, explained principal investigator Dr Ula Jurkunas, associate director of the Cornea Service at Mass Eye and Ear and professor of ophthalmology at Harvard Medical School. This new data shows that CALEC is more than 90% effective at restoring the cornea’s surface, making a meaningful difference to patients with cornea damage that was previously considered untreatable, she said.

The study showed CALEC completely restored the cornea in 50% of participants at their three-month visit, with the success rate increasing to 79% and 77% at the patients 12- and 18-month visits, respectively. The overall success rate was 93% and 92% at 12 and 18 months, with varying levels of visual acuity improvement reported in all 14 patients and no serious events occurring in either the donor or recipient eyes, said the study team.

CALEC is both the US’ first eye stem-cell therapy and the first to be FDA-compliant, they said. “Our findings show that transplantation of CALEC constructs in patients with both mild and severe forms of LSCD achieved corneal surface restoration with limbal epithelial cells and improved clinical symptoms.” CALEC performed well in achieving the efficacy outcome for corneal surface integrity, with a manufacturing success of 93%, they said.