New Human Embryonic Stem Cell Study For Dry AMD And Stargardt's Macular Dystrophy
Two patients have been treated using RPE (retinal pigment epithelial) cells derived from hESCs (human embryonic stem cells) in two Phase 1/2 clinical trials for dry age-related macular degeneration and Stargardt's macular dystrophy, Advanced Cell Technology Inc. has announced.
According to Dr. Steven Schwartz and Dr. Robert Lanza, the transplantation surgeries, which took place at the Jules Stein Eye Institute, California, were successful and both patients are recovering well.
Advanced Cell Technology says the two trials will enroll 12 patients in each one, with 3-patient cohorts in ascending dosage format. The primary endpoint is to establish safety and tolerability of hESC-derived RPE cells, after transplantation sub-retinally into patients with dry AMD and Stargardt's at 12 months. The investigators will also be looking for signs that the cells helped restore vision. In animal studies, rats experienced some recovery of vision.
Gary Rabin, interim chairman and chief executive officer of Advanced Cell Technology, said:
"This first treatment milestone is welcomed by scientists, stem cell advocates and patients hoping for cures. The two trials could not have started any smoother, and we are very pleased to announce that the procedures went well. The dosing of the first patients represents an important milestone for ACT and opens the doors to a potentially significant new therapeutic approach to treating the many forms of macular degeneration. We believe that these procedures represent a key step forward in therapeutic stem cell research, and the capacity to treat a variety of devastating diseases."
The studies' main investigator, Dr. Schwartz, said:
"One patient in each clinical trial, the Stargardt's trial and the dry AMD trial, has undergone surgical transplantation of a relatively small dose (50,000 cells) of fully-differentiated retinal pigment epithelial (RPE) cells derived from human embryonic stem cells. Early indications are that the patients tolerated the surgical procedures well. The primary objective of these Phase 1/2 studies is to assess the safety and tolerability of these stem cell-derived transplants. We will be carefully monitoring our patients over the course of the trials. We are privileged to be collaborating with ACT and honored to be working with these pioneering patients."
Stargardt's macular dystrophy, dry AMD and other types of atrophy-related macular degeneration are generally impossible to treat. These common forms of blindness urgently need safe and effective therapies.
Dr. Lanza said:
"Today -13 years after the discovery of human embryonic stem cells - the great promise of these cells is finally being put to the test. The initiation of these two clinical trials marks an important turning point for the field. While we will continue writing research papers and carrying out more research, it's time to start moving these exciting new stem cell therapies out of the laboratory and into the clinic.
Tens of thousands of people continue to die every day from diseases that could potentially be treated using stem cells. In the meantime, we intend to accelerate our efforts to translate new embryonic stem cell (ES) and induced pluripotent stem (iPS) cell therapies into the clinic. It has taken years of extensive research to get to this point. Our research and preclinical studies have demonstrated the safety and effectiveness of such therapies.
We hope these cells may provide a treatment option not only for degenerative eye diseases, but for a wide spectrum of other debilitating conditions, ranging from diabetes to vascular and autoimmune diseases. Our team remains committed to moving the field of regenerative medicine forward from bench to bedside."
In November, 2010, the FDA (Food and Drug Administration) approved Advanced Cell Technology's application to test cells created from human embryonic stem cells on 12 volunteers. Between 50,000 and 200,000 retinal pigmented epithelial cells derived from human embryonic stem cells will be injected into the patients' eyes. Hopefully, the new cells will replace those destroyed by dry AMD and Stargardt's macular dystrophy.
Human embryonic stem cell research is very controversial. The scientific community mainly believe that it can lead to treatments and cures for many devastating diseases. However, embryos a few days old have to be destroyed to get these cells, which many people are against for ethical reasons. There is also concern about safety - some people say the approach has not been tested enough and should not yet be tried on human beings.
Embryos used in embryonic stem cell research are usually extras that have been created in in-vitro fertilization (IVF) clinics - several eggs are fertilized in a test tube, but only one is implanted into the woman.
Advanced Cell Technology's stock price has gone up 170% so far this year. The company is valued at $285 million. Market experts believe it could be worth many billions if these trials are successful. Macular degeneration affects approximately 10 million people in the USA.
Embryonic stem-cell research has not been a money-maker so far. Advanced Cell Technology accumulated losses of over $180 million since it started in the mid-1990s.
What are hESC-RPE Cells?
RPE (retinal pigment epitheliom) is an extremely thin, pigmented cell layer just below the retina. It nourishes the photoreceptors as well as carrying away waste products. Human embryonic stem cells can turn into (differentiate) into any type of cell, including RPE cells.
SMD, Dry AMD and Degenerative Diseases of the Retina
SMD (Stargardt's macular dystrophy), a common form of macular degeneration, causes progressive loss of vision. The disease usually starts when the patient is between 10 to 20 years old. Photoreceptor loss caused by degeneration in the pigmented layer of the retina (RPE cell layer) eventually leads to blindness.
Degenerative retinal diseases are one of the most common causes of untreatable blindness worldwide. Experts estimate that in the USA and Europe alone approximately 30 million people suffer from macular degeneration - a global market in excess of $25 billion. One in every ten individuals aged between 66 and 74 years is thought to have macular degeneration symptoms, most of them with dry AMD, which is untreatable. Three in every ten individuals aged between 75 and 85 are believed to be affected.
Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today
it's time to start moving these exciting new stem cell therapies out of the laboratory and into the clinic
把胚胎干细胞治疗这项技术从实验室走出来并应用到临床的时候到了。作者: 福娃晶晶 时间: 2011-7-15 18:09
