Released:10/1/2012 1:10 PM EDT
An experimental treatment for blindness, developed from a patient’s skin cells, improved the vision of blind mice in a study conducted by Columbia ophthalmologists and stem cell researchers.
The findings suggest that induced pluripotent stem (iPS) cells – which are derived from adult human skin cells but have embryonic properties – could soon be used to restore vision in people with macular degeneration and other diseases that affect the eye’s retina.
“With eye diseases, I think we’re getting close to a scenario where a patient’s own skin cells are used to replace retina cells destroyed by disease or degeneration,” says the study’s principal investigator, Stephen Tsang, MD, PhD, associate professor of ophthalmology and pathology & cell biology. “It’s often said that iPS transplantation will be important in the practice of medicine in some distant future, but our paper suggests the future is almost here.”
The advent of human iPS cells in 2007 was greeted with excitement from scientists who hailed the development as a way to avoid the ethical complications of embryonic stem cells and create patient-specific stem cells. Like embryonic stem cells, iPS cells can develop into any type of cell. Thousands of different iPS cell lines from patients and healthy donors have been created in the last few years, but they are almost always used in research or drug screening.
No iPS cells have been transplanted into people, but many ophthalmologists say the eye is the ideal testing ground for iPS therapies.
“The eye is a transparent and accessible part of the central nervous system, and that’s a big advantage. We can put cells into the eye and monitor them every day with routine non-invasive clinical exams,” Tsang says. “And in the event of serious complications, removing the eye is not a life-threatening event.”
MARLBOROUGH, Mass. — July 26, 2012 – Advanced Cell Technology, Inc. (“ACT”; OTCBB: ACTC), a leader in the field of regenerative medicine announced today that it has been issued a patent in Australia, patent number 2005325753, “Improved modalities for the treatment of degenerative diseases of the retina.” The patent broadly covers the use of human retinal pigment epithelial (RPE) cells generated from pluripotent stem cells in the manufacture of pharmaceutical preparations of RPE cells, and the use of those preparations to treat patients with degenerative diseases of the retina such as Age-related Macular Degeneration. The patent covers the pharmaceutical formulation of human RPE cells made from a range of pluripotent stem cells, including both human embryonic stem cells (hESCs) and human induced pluripotent stem (iPS) cells.
“We continue to make great progress with our patent estate covering RPE therapies,” said Gary Rabin, chairman and CEO of ACT. “Our ongoing success in securing broad patent protection around the world, including this newly-issued Australian patent, is a testament to our innovative chief scientific officer, Dr. Robert Lanza, and the rest of our scientific team.”
The efficient production of highly pure RPE cell preparations represents a critical step in the creation of renewable sources of transplantable cells that can be used to target degenerative diseases of the eye such as Stargardt’s Macular Dystrophy (SMD) and dry Age-related Macular Degeneration (dry AMD).
“Our current embryonic stem cell trials pave the way for other pluripotent stem cell therapies,” commented Dr. Lanza. “ACT’s cellular reprogramming technologies using iPS cells are in an advanced stage of development, and we hope to be in a position to move toward clinical translation in the not-too-distant future. Since iPS cells can be made from the patient’s own cells such as skin or blood cells they may allow us to expand our cell therapies beyond immune-privileged sites such as the eye without the risk of immune rejection.”
Mr. Rabin concluded, “We are aggressively pursuing patent protection for a variety of aspects of our programs. Our intellectual property strategy includes both vigilance in pursuing comprehensive coverage from our initial patent filings, such as this new Australian patent, and filing for protection around our scientific team’s various innovations. At the same time we are paying close attention to including within our patent coverage those ways others may wish to adapt our technology for commercial use, such as through the choice of stem cell source, or the use of solid supports or cell suspensions for delivery. Following this strategy, we are establishing both formidable barriers-to-entry for potential competitors, as well as strong potential licensing opportunities for others, translating into solid revenue generation possibilities for the company.”
In Tsang’s new preclinical iPS study, human iPS cells – derived from the skin cells of a 53-year-old donor — were first transformed with a cocktail of growth factors into cells in the retina that lie underneath the eye’s light-sensing cells.
The primary job of the retina cells is to nourish the light-sensing cells and protect the fragile cells from excess light, heat, and cellular debris. If the retina cells die – which happens in macular degeneration and retinitis pigmentosa – the photoreceptor cells degenerate and the patient loses vision. Macular degeneration is a leading cause of vision loss in the elderly, and it is estimated that 30 percent of people will have some form of macular degeneration by age 75. Macular degeneration currently affects 7 million Americans and its incidence is expected to double by 2020.
In their study, the researchers injected the iPS-derived retina cells into the right eyes of 34 mice that had a genetic mutation that caused their retina cells to degenerate.
In many animals, the human cells assimilated into mouse retina without disruption and functioned as normal retina cells well into the animals’ old age. Control mice that got injections of saline or inactive cells showed no improvement in retina tests.