alt=watering can pours water onto flowers that are growing into parts of an eye.

Researching Clinical Trials and Stem Cell Therapies

Last updated: June 2021

Hi! Recently I was looking over some work a friend had done for her macular degeneration Facebook group. In the references, she had included a press release from OpRegen. They announced the rollout of a phase 1 and 2a open-label, dose-escalation safety and efficacy study of a single injection of human retinal pigment epithelial cells, (RPEs), derived from established pluripotent cell lines and transplanted sub-retinally in patients with advanced dry AMD with GA.

Oh my! I am not quite sure we will get past the vocabulary on this one. And that is only the first line of the release!

What is regenerative medicine?

So, why am I taxing my little brain - and by extension your brain - to even look at such a thing? To begin with, when you say "OpRegen" you are saying the name of a big player in regenerative medicine. Regenerative medicine deals with “growing back” parts and making other, such repairs. Talking regenerative medicine, you are talking stem cells and you are talking my Jerusalem, Valhalla, Nirvana, wherever people dream of being. Stem cell studies have been my goal since I was diagnosed with geographic atrophy, aka advanced, dry, age-related macular degeneration.

The reason for that is simple: my maculas are pretty much gone. Look to the backs of my eyes and you can see down to the choroid. When it comes to photoreceptors and support cells, there is none there and they will not grow back on their own. Unless I get stem cells to replace them, dead is dead.

Stem cell research is starting to crank

Fortunately for me and maybe you, stem cell research is starting to crank. While in the early stages of clinical trials - phase 1/2a - the research has graduated from animal (preclinical trials) and is moving along nicely.

We have talked about the phases of a clinical trial in the past, but it might bear repeating.

Phases of clinical trials

Phase 1 is solely safety and tolerability. In medicine the cardinal rule is “first, do no harm” and that is what phase 1 is about. Phase 2 is about efficacy. Does the treatment do what I want it to do? Phase 2a has to do with safety in dosage as well as efficacy. How much is too little? How much is too much?

Stem cell research vs. clinical trials

And while talking about safety, I cannot remind you enough: stem cell research is in its infancy. It has not been approved by the FDA and will not be approved for years. If someone is offering “stem cell treatments”, run the other way. Especially run the other way if they want to charge you big bucks. The only places you can get stem cell treatments are hospitals and some clinics in which they are running research for the big names. Also, clinical trials are essentially at no cost to the patient. Not thousands of dollars...ever.

Clinial trial language


"Open-label" is a phrase meaning everybody involved knows the treatment you are getting. You know. The doctor charting your progress knows. The experimenter knows. It is the opposite of a double-blind experiment in which the only person who knows is the experimenter.

And that is only the first line of print! Phew! Moving on to the next line!

Dose escalation and single-injection

Dose escalation means the different groups get a different amount of treatment. We already went over safety and efficacy, efficacy being if it works. Single-injection is just that, one treatment. That is all simple enough. On to the third line of print!

Retinal pigment epithelial aka RPE

Retinal pigment epithelial has been covered in these pages before. I describe them as servants to our photoreceptors. Photoreceptors really cannot take care of themselves. They need their servants to keep them alive.

However, and this is a big however. RPEs cannot see. In other words, getting RPE stem cells will not restore vision per se. You cannot grow crops without good soil, but just having good soil does not mean you have crops. Yes/no? The increase in vision when people are given RPEs is the result of a “rescue operation”. Photoreceptor cells that were on their proverbial last legs get a new lease on life and start functioning again.

Knowledge is power!

The stuff about pluripotent cell lines and subretinal transplant is going to have to wait for another page. It won’t get done in 100 words! In fact, they could each be a page.

That said, class dismissed! And don’t be afraid of this stuff. They are your eyes and you should be able to help make informed decisions about them. After all, knowledge really is power!

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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