Twelve people left almost blind by a hereditary condition that strikes in childhood are to receive the world鈥檚 first eye therapy derived from human embryonic stem cells (hESCs).
The treatment is for Stargardt鈥檚 macular dystrophy, which affects 1 in 8000 people in the US. Their sight deteriorates from around age 6 when retinal pigment epithelial cells (RPEs) start to die off rapidly, possibly due to a defective gene. Without RPEs to support and nourish them, adjacent photoreceptor cells which capture light signals, die too and blindness is the result.
People in the trial will be those whose vision has deteriorated to the point where they can see the movement of their own hand, but little else. They will receive injections into their eyes of between 50,000 and 200,000 RPEs.
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鈥淭he goal is to halt the rate of photoreceptor loss,鈥� says Robert Lanza, chief scientist at of Worcester, Massachusetts, the company that has been developing the treatment since first turning hESCs into RPEs in 2004. By implanting new RPEs, which do not contain the defective gene, the team hopes to prevent further deterioration or perhaps even reverse it.
Vision in six months
鈥淲e will hopefully show safety, and we may be able to see improvements in vision in as little as six months,鈥� says Lanza.
It will be relatively easy for the team to monitor the fate of the new cells because they can be seen in the eye through a microscope. They can also be removed if there are any adverse effects.
This contrasts with the first trial of an hESC-derived treatment for spinal cord injuries, which began in October. There is no way of knowing the fate of the injected cells.
鈥淪targardt鈥檚 is an ideal indication,鈥� says Lanza. 鈥淭here鈥檚 a definitive endpoint, for measuring visual acuity.鈥�
Surgeons will inject the cells into the retina in the space usually occupied by RPEs, directly adjacent to the photoreceptor cells.
Macular degeneration next
In the coming weeks, ACT will apply to the FDA to conduct a separate trial in age-related macular degeneration, in which ageing of RPEs eventually causes blindness, a condition affecting 30 million people worldwide.
Other stem cell eye researchers were delighted with the news. 鈥淚t鈥檚 fantastic news that they are going into the clinic with a cell therapy for eye disease,鈥� says of University College London, and head of a team developing tiny 鈥減atches鈥� of RPEs for treating age-related macular degeneration.
Lanza says the first volunteer could be treated within around 2 months at one of the half-dozen eye hospitals around the US collaborating in the trial. Treatments based on hESCs for a whole range of conditions from diabetes to heart disease are also moving towards trials, as 快猫短视频 reported last year.
