March 19, 2018

expert reaction to using stem cells to treat macular degeneration

A study published in Nature Biotechnology describes a phase 1 clinical trial of an embryonic stem cell-derived retinal pigment epithelium patch for age-related macular degeneration.

Dr Carmel Toomes, Associate Professor, Leeds Institutes of Molecular Medicine, said:

Does the press release accurately reflect the science?

“The press release does accurately reflect the science.”

Is this good quality research?  Are the conclusions backed up by solid data?

“It’s sound science and the conclusions are realistic. The authors do say the data is only from two patients, however such a small sample size is normal for phase 1 clinical studies like this.”

How does this work fit with the existing evidence? 

“Using stem cells technology to replace the dead cells in neuronal tissue is a major topic in medical research. A few teams are investigating using stem cell derived RPE cells to replace the RPE cells which die as a result of age-related macular degeneration, as well as the rarer inherited forms of retinal degeneration. Previous studies have injected the RPE cells directly into the patient whereas in this study the researchers have developed a novel piece of technology which they call a “patch” on which they first grow the RPE cells. This allows the cells to grow in the correct orientation and this could potentially help the cells integrate into the retina. The authors here are reporting that this “patch” worked and the cells were integrated into the patient’s eye.

“What’s exciting about this study is that the patients recorded an increase in vision. Patients with very poor vision are chosen for phase 1 trials because of their “untested” nature. To see an improvement is a good sign that that this therapy may help patients in the future, although further studies are needed before real conclusions can be drawn.”

What are the implications in the real world?  Is there any overspeculation?

“The authors have been responsible in their reporting of the study, and in particular the improvements in vision seen in the patients. These improvements are only anecdotal at the moment as this was not the outcome being tested with this study. The authors clearly state this in the paper.

“These results give the many patients out there who suffer from AMD and other retinal degenerations real hope that stem cells replacement therapy may be a reality in the near future. While this is only a very early clinical trial, the results are positive and show that the technology is moving along. In the right direction.”

Prof John Hunt, Head of the Strategic Research Theme Medical Technologies and Advanced Materials, Nottingham Trent University, said:

“The authors present a well-balanced, experimentally evidenced case for having taken in to consideration all that is known about ESC at this point in time; experimentally they have attempted to address the known safety concerns surrounding ESCs and their potential to form tumours (teratomas). The authors also point out correctly, the eye is a very special location in the body, in that it is quite isolated in terms of cell migration, possibly it is immuno privileged. We can view inside the eye non-invasively, which is perfect to monitor progress and should there be a need to remove cells there is a good chance we would be able to find them and do that.  The eye’s easy physiological access and the current increasing unmet medical need to treat eye diseases globally like AMD make the eye a logical place to trial the use of cellular therapies. We should learn a great deal from this study in the longer term, let’s hope that it is all positive and helps us take massive steps forwards towards demonstrating the clinical efficacy of cellular therapies to address many others of our pressing clinically unmet needs.”

Dr Dusko Ilic, Reader in Stem Cell Science, King’s College London (KCL), said:

“Even though still in the experimental stage, encouraging results from the da Cruz team are reducing further safety concerns with the human embryonic stem cell (hESC)-based therapies. They represent another step forward in materializing our hopes of clinical implementation of hESC-based treatment of age-related macular degeneration in the not so distant future.”

* ‘Phase 1 clinical study of an embryonic stem cell–derived retinal pigment epithelium patch in age-related macular degeneration’ by Lyndon da Cruz et al. published in Nature Biotechnology on Monday 19th March. 

All our previous output on this subject can be seen at this weblink: http://www.sciencemediacentre.org/tag/embryonic-stem-cells/

Declared interests

Dr Carmel Toomes: I have no conflicts/objections to declare regarding this study.

Prof John Hunt: No conflicts of interest

Dr Dusko Ilic: I declare no conflict of interest with the study.

None others received.