Eyestem Research could become the first Indian firm to develop cellular therapies for dry age-related macular degeneration (AMD) aimed for the local population.
Currently the eye condition is one of the leading causes of vision loss globally and is managed with either injections or a cocktail of vitamin supplements. These treatments, while helpful in slowing the progression of the condition, cannot cure it.
“Around 170 million people in the world suffer from it [AMD] with 40 million estimated to be in India and it is the largest cause of blindness for people over 50,” says Dr Jogin Desai, founder, and CEO of Eyestem Research, located in Bengaluru.
The company, backed by the Centre for Cellular and Molecular Platforms (C-CAMP), is now looking to move into human trials for its therapy after successful animal tests. The therapy can replace damaged retinal pigment epithelium and restore vision in those who are slowly losing it.
The need for an AMD cure
AMD is a common eye condition where a part of the retina called the macula deteriorates for many reasons – age, genetics, and lifestyle factors. The macula is the central part of the retina that is responsible for central vision and needed for activities like reading, writing, driving, and recognizing faces.
The retina is a complex tissue made up of ten layers of which the retinal pigmental epithelium (RPE) layer is vital for supporting the function of the photoreceptor cells in the macula.
There are two forms of AMD – dry and wet. The dry form has no treatment that can reverse the damage to the retina whereas the wet form can be treated with the help of anti-injections. Vascular endothelial growth factor (VEGF) is a protein that promotes the growth of blood vessels and anti-VEGF injections stop this growth.
“There is an accumulation of debris and waste products underneath the retinal pigment epithelium layer called as drusen,” explains Dr T P Vignesh, retina consultant and professor of ophthalmology at Aravind eye hospital, Madurai. “As this accumulation builds up, there is atrophy [shrinking] of the retinal epithelium cells and the overlying photoreceptor cells,” adds Dr Vignesh, explaining what causes damage to the RPE, leading to visual impairment.
Once it progresses to an advanced stage, known as geographic atrophy, it is characterised by increased damage to the macula. “Once it goes to the advanced stage – [people with the condition] become legally blind – they may have some vision, but they cannot read, write or drive,” says Dr Vignesh.
Treatments for AMD work by slowing down the progression of the eye condition in its early stages. The Food and Drug Agency (FDA) has granted approval to the biotech company Apellis to treat geographic atrophy in the US.
The understanding of the causes of AMD is still evolving, and researchers are working to identify the specific biological mechanisms that lead to the disease.
“It is theoretically possible that stem cells may replace it [retinal cells]. However, we still don’t have a product in the market which can do this, but it may come soon,” adds Dr Vignesh.
Harnessing the power of stem cells
Many people are exploring cellular therapies for conditions where cells in the body are damaged or die. There is potential for reversing damage to retinal cells using stem cells.
By using a well-characterised clinical stem cell line from the National Institute of Health in the US, Eyestem set out to create a product containing RPE cells derived from induced pluripotent stem cells (iPSC). This allogenic (donor) cell product currently holds patents in both India and the US and has been studied in terms of its safety and efficacy in animals.
“We started by creating a lot of cells in the lab and decided to focus on the eye first,’’ says Desai. It is easier to scale up a cell product for the eye as a small number of cells are needed compared to other organs in the body, he adds.
“We saw that rats which are injected with our stem cells were able to preserve their eyesight versus those which were not,” says Desai.
Additionally, their stem cell product is being tested on non-human primates for which they are collecting data.
“We are at the stage where we are compiling the reports and looking to start testing in humans soon. We will get our AMD treatment to be in human clinical trials [within] this year,” adds Desai.
Expanding horizons
Eyestem has also entered into a collaboration with LV Prasad eye institute, Hyderabad to manufacture their product in a GMP-graded facility.
“We must make sure it [manufacturing] is consistent and dependable. People need to be able to repeat the same thing consistently as stem cells can have batch to batch variability,” says Desai.
For future work, Eyestem wants to tackle retinitis pigmentosa – a genetic disease that is diagnosed in childhood and can lead to blindness in adulthood – using photoreceptor cells grown in the lab. Besides the eye, they are also studying lung fibrosis by growing alveolar organoids in the lab.
“I look forward to the day when somebody who was going blind will not go blind because of the work done our lab,” says Desai.
Key takeaways on maintaining eye health
There are several lifestyle factors that can put you at risk of developing AMD as you age. Dr Vignesh suggests these simple tips to follow:
- Regular eye check-ups after the age of 50
- Avoiding sunlight by using a UV filter
- Avoiding smoking and alcohol consumption
- Consuming nutritious meals that include fresh and leafy vegetables, fatty fishes like salmon, milk and eggs.