Study: Gene therapy effective in hereditary blindness

(Image Credit: AdobeStock/Kai Zhao)

A team of researchers at the Karolinska Institute are investigating whether gene therapy can improve vision in people with Bothnia dystrophy is a form of hereditary blindness, prevalent in the region Västerbotten in Sweden.

The study, published in Nature Communications, demonstrates that gene therapy can improve vision in patients with the disease.¹

The researchers noted that Bothnia dystrophy occurs primarily in the region Västerbotten in Sweden. However, it has also been identified in other parts of the world, including the United States. The disease leads to progressive visual impairment as a result of the destruction of the visual cells in the retina. The disease is caused by an inherited genetic mutation that leads to damage to a particular protein in the eye. There is currently no treatment for the disease.²

Researchers used a viral vector, a specially designed virus that was genetically modified to contain a functioning RLBP1 gene, the gene that is damaged in Bothnia dystrophy.³

Then researchers noted the viral vector was injected in 12 people diagnosed with the diseases under the retina through a surgical procedure. Their hope is that after treatment, the viral vector will be taken up by the cells of the retina, where it can produce normal protein.

According to the study, the preliminary results showed that the visual function of 11 of the subjects improved significantly.

“The results are important because hereditary blindness is the most common cause of blindness in younger and able-bodied people, and there is no treatment for the vast majority of those affected,” according to Helder André, PhD, a researcher involved in the study, who works at the Department of Clinical Neuroscience, Karolinska Institutet.

Following the procedure, the team followed the study subjects for a year to study the safety and effect of the drug on visual function. In 11 of the 12 study subjects, night vision, among other things, improved significantly, and in several participants, this led to improved self-perceived quality of life. No serious side effects linked to the drug were noted in the study.

Anders Kvanta, professor of ophthalmology at the same department and the person who led the study, said it offers hope that this large group of patients can have their vision restored in the future.

“The results also support the idea that gene therapy can work for hereditary diseases in general,” Kvanta said.

According to researchers, the next step is a larger study comparing the effect on treated study subjects with a control group that has not been treated.

The study was conducted at St. Erik Eye Hospital in Stockholm, and was Novartis and the study team included Novartis employees. None of the team at St. Erik's Eye Hospital has ties to Novartis or any other conflict of interest.²

References:

1. Anders Kvanta, Nalini Rangaswamy, Karen Holopigian, Christine Watters, Nicki Jennings, Melissa S. H. Liew, Chad Bigelow, Cynthia Grosskreutz, Marie Burstedt, Abinaya Venkataraman, Sofie Westman, Asbjörg Geirsdottir, Kalliopi Stasi, and Helder André, Interim safety and efficacy of gene therapy for RLBP1-associated retinal dystrophy: a phase 1/2 trial, Nature Communications, Published online September 10, 2024, Accessed Sep[tember 15, 2024. doi: 10.1038/s41467-024-51575-4

2. Bothnia retinal dystrophy | About the Disease | GARD. Nih.gov. Published 2024. Accessed September 16, 2024. https://rarediseases.info.nih.gov/diseases/16734/bothnia-retinal-dystrophy

3. Gene therapy effective in hereditary blindness. EurekAlert! Published September 10, 2024. Accessed September 16, 2024. https://www.eurekalert.org/news-releases/1057203