CIRM-funded research aims to create a platform to test therapies for AMD

People with late stage age-related macular degeneration lose their central vision. So an image like the one on the left might appear to them as shown on the right.
Credit: University of California – Santa Barbara

Our vision is one of the most important senses that we use in our everyday lives. Whether its to help somebody perform complex surgeries or soak in a beautiful impressionist painting, a layer of cells in the back of the eye called the retinal pigment epithelium (RPE) provide support to photoreceptors (PRs), specialized cells that play an important role in our ability to process images. Unfortunately, as we get older, problems with this part of the eye can begin to develop.

Age-related macular degeneration (AMD) is an eye disease that causes severe vision impairment, resulting in the inability to read, drive, recognize faces, and blindness if left untreated.  It is the leading cause of vision loss in the U.S. and currently affects over 2 million Americans.  By the year 2050, it is projected that the number of affected individuals will more than double to over 5 million. The dysfunction and/or loss of RPE cells plays a critical role in the loss of PRs and hence the vision problems observed in AMD. One form of AMD for which there is no treatment is known as dry AMD (dAMD) and accounts for about 90% of all AMD cases. This version of dAMD is due to the inability of the RPE cells to heal.

CIRM-funded research at UC Santa Barbara aims to create a platform to test therapies for dAMD. Led by Dr. Peter Coffey and Dr. Lindsay Bailey-Steinitz, the team outlined two main objectives for this project. The first was to better understand what is occurring at the cellular level as the disease advances. The second was to develop a model that could be used to test therapeutics.

In a press release, Dr. Bailey-Steinitz discusses the importance of developing a disease model for dAMD.

“Part of the struggle of finding a treatment option is that we’ve not been able to really model the progression of the disease in cell culture or in animals.”

An overview of Dr. Coffey and Dr. Bailey-Steinitz’s experiment.
Credit: Lindsay Bailey-Steinitz

In dAMD, when RPE cells fail to repair themselves, they form a hole that gradually continues to expand. Dr. Bailey-Steinitz recreated this hole in the lab by culturing RPE cells on a plate with an electrode and then zapping them. This process created a hole very similar to the one that appears in dAMD. However, since the cells used in this experiment were younger cells, they were more prone to self healing. But the team found that 10 pulses of electricity over the course of 10 days prevented the younger cells from healing. The team also found that shocking the cells suppressed important genes involved in RPE cell function.

The team is planning future experiments with older cells since they demonstrate a decreased ability to heal.

In the same press release, Dr. Coffey highlights the potential impact of this work.

“”If we can improve this setup, then we’ve got a therapeutic testbed for AMD.”

CIRM has also funded a separate clinical trial for dAMD conducted by Dr. Mark Humayun at the University of Southern California.

The full results of this study were published in PLOS ONE.

Study highlights the problem patients have in taking part in clinical trials and one simple way to change that

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Photo: courtesy Medical Daily

Let’s face it, when you are feeling crummy all you want to do is be quiet, rest and not have to deal with anyone else. So, it’s not surprising that a new survey of people with primary mitochondrial disease (PMD) found that many were often less than enthusiastic about taking part in a clinical trial.

It’s not surprising because PMD, caused by problems with the mitochondria which provide energy within our cells, can lead to a wide variety of debilitating conditions including muscle weakness, visual problems, hearing problems, heart disease, liver disease, kidney disease, gastrointestinal disorders, breathing problems, neurological problems and dementia. Any one of those is bad enough, but if you combine several you can see why it would be hard for a person with PMD to get to a clinical trial site for an experimental therapy.

That’s unfortunate because right now there are no effective treatments for PMD so it’s vitally important that people take part in clinical trials that might lead to new therapies.

Obstacles and opportunities

Fortunately, this study, published in the journal PLOS One, did more than just identify the barriers to taking part in a clinical trial, it also identified some strategies to overcome those barriers.

The barriers included not just the individual’s state of health but also:

  • Requiring patients to discontinue current medications
  • Daily blood tests
  • Requiring patients to pay for the cost of the clinical trial

Ways to encourage increased participation include:

  • Direct communication with a physician involved in the trial
  • Better education and outreach to people with PMD
  • Working with patient advocacy groups

The study says this last point in particular is extremely important.

“We propose widespread, coordinated efforts that involve PMD patient advocacy groups to organize community education sessions that clarify the components and need for efficacious clinical trial design.”

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CIRM CAP meeting

This is something that CIRM knows a lot about. Whenever we fund a clinical trial – or, in some cases a late stage pre-clinical program – we create a Clinical Advisory Panel (CAP) to support it. Each CAP consists of an independent, outside expert in whatever disease the trial is targeting, a CIRM Science Officer, and a Patient Advocate. The Patient Advocate plays a vital role in making sure this project works.

Researchers know the science, but the Patient Advocate knows what it is like to live with the disease and the limitations it may impose. They can help guide and advise the researchers on how to design a clinical trial that works for the patients and makes it as easy as possible for them to be part of the trial.

In the last few years we have created 68 CAPs, ensuring the voice of the patient, and the needs of the patient, are front and center in everything we do.

The easier it is for the patient, the easier it will be to recruit people for the trial and the more likely it is they will stay with the trial to the end. It won’t guarantee the therapy will succeed, but it gives it the best possible chance.