Throwback Thursday: Progress to a Cure for Diseases of Blindness

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of exciting stem cell stories about advances towards stem cell-based cures for serious diseases. This month we’re featuring stories about CIRM-funded clinical trials for blindness.

2017 has been an exciting year for two CIRM-funded clinical trials that are testing stem cell-based therapies for diseases of blindness. A company called Regenerative Patch Technologies (RPT) is transplanting a sheet of embryonic stem cell-derived retinal support cells into patients with the dry form of age-related macular degeneration, a disease that degrades the eye’s macula, the center of the retina that controls central vision. The other trial, sponsored by a company called jCyte, is using human retinal progenitor cells to treat retinitis pigmentosa, a rare genetic disease that destroys the light-sensing cells in the retina, causing tunnel vision and eventually blindness.

 

Both trials are in the early stages, testing the safety of their respective stem cell therapies. But the teams are hopeful that these treatments will stop the progression of or even restore some form of vision in patients. In the past few months, both RPT and jCyte have shared exciting news about the progress of these trials which are detailed below.

Macular Degeneration Trial Gets a New Investor

In April, RPT announced that they have a new funding partner to further develop their stem cell therapy for age-related macular degeneration (AMD). They are partnering with Japan’s Santen Pharmaceutical Company, which specializes in developing ophthalmology or eye therapies.

AMD is the leading cause of blindness in elderly people and is projected to affect almost 200 million people worldwide by 2020. There is no cure or treatment that can restore vision in AMD patients, but stem cell transplants offer a potential therapeutic option.

RPT believes that their newfound partnership with Santen will accelerate the development of their stem cell therapy and ultimately fulfill an unmet medical need. RPT’s co-founder, Dr. Dennis Clegg, commented in a CIRM news release, “the ability to partner with a global leader in ophthalmology like Santen is very exciting. Such a strong partnership will greatly accelerate RPT’s ability to develop our product safely and effectively.”

This promising relationship highlights CIRM’s efforts to partner our clinical programs with outside investors to boost their chance of success. It also shows confidence in the future success of RPT’s stem cell-based therapy for AMD.

Retinitis Pigmentosa Trial Advances to Phase 2 and Receives RMAT Status

In May, the US Food and Drug Administration (FDA) approved jCyte’s RP trial for Regenerative Medicine Advanced Therapy (RMAT) status, which could pave the way for accelerated approval of this stem cell therapy for patients with RP.

RMAT is a new status established under the 21st Century Cures Act – a law enacted by Congress in December of 2016 to address the need for a more efficient regulatory approval process for stem cell therapies that can treat serious or life-threatening diseases. Trial sponsors of RMAT designated therapies can meet with the FDA earlier in the trial process and are eligible for priority review and accelerated approval.

jCyte’s RMAT status is well deserved. Their Phase 1 trial was successful, proving the treatment was safe and well-tolerated in patients. More importantly, some of the patients revealed that their sight has improved following their stem cell transplant. We’ve shared the inspiring stories of two patients, Rosie Barrero and Kristin Macdonald, previously on the Stem Cellar.

Rosie Barrero

Kristin MacDonald

Both Rosie and Kristin were enrolled in the Phase 1 trial and received an injection of retinal progenitor cells in a single eye. Rosie said that she went from complete darkness to being able to see shapes, colors, and the faces of her family and friends. Kristin was the first patient treated in jCyte’s trial, and she said she is now more sensitive to light and can see shapes well enough to put on her own makeup.

Encouraged by these positive results, jCyte launched its Phase 2 trial in April with funding from CIRM. They will test the same stem cell therapy in a larger group of 70 patients and monitor their progress over the next year.

Progress to a Cure for Blindness

We know very well that scientific progress takes time, and unfortunately we don’t know when there will be a cure for blindness. However, with the advances that these two CIRM-funded trials have made in the past year, our confidence that these stem cell treatments will one day benefit patients with RP and AMD is growing.

I’ll leave you with an inspiring video of Rosie Barrero about her experience with RP and how participating in jCytes trial has changed her life. Her story is an important reminder of why CIRM exists and why supporting stem cell research in particular, and research in general, is vital for the future health of patients.


Related Links:

Throwback Thursday: Progress to a Cure for Type 1 Diabetes

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of valuable stem cell stories on our blog. Some of these stories represent crucial advances towards stem cell-based cures for serious diseases and deserve a second look.

novemberawarenessmonthThis week in honor of Diabetes Awareness Month, we are featuring type 1 diabetes (T1D), a chronic disease that destroys the insulin-producing beta cells in your pancreas. Without these important cells, patients cannot maintain the proper levels of glucose, a fancy name for sugar, in their blood and are at risk for many complications including heart disease, blindness, and even death.

Cell replacement therapy is evolving into an attractive option for patients with T1D. Replacing lost beta cells in the pancreas is a more permanent and less burdensome solution than the daily insulin shots (or insulin pumps) that many T1D patients currently take.

So let’s take a look at the past year’s advances in stem cell research for diabetes.

Making Insulin-Producing Cells from Stem Cells and Skin

This year, there were a lot of exciting studies that improved upon previous methods for generating pancreatic beta cells in a dish. Here’s a brief recap of a few of the studies we covered on our blog:

  • Make pancreatic cells from stem cells. Scientists from the Washington University School of Medicine in St. Louis and the Harvard Stem Cell Institute developed a method that makes beta cells from T1D patient-derived induced pluripotent stem cells (iPSCs) that behave very similarly to true beta cells both in a dish and when transplanted into diabetic mice. Their discovery has the potential to offer personalized stem cell treatments for patients with T1D in the near future and the authors of the study predicted that their technology could be ready to test in humans in the next three to five years.
  • Making functional pancreatic cells from skin. Scientists from the Gladstone Institutes used a technique called direct reprogramming to turn human skin cells directly into pancreatic beta cells without having to go all the way back to a pluripotent stem cell state. The pancreatic cells looked and acted like the real thing in a dish (they were able to secrete insulin when exposed to glucose), and they functioned normally when transplanted into diabetic mice. This study is exciting because it offers a new and more efficient method to make functioning human beta cells in mass quantities.

    Functioning human pancreatic cells after they’ve been transplanted into a mouse. (Image: Saiyong Zhu, Gladstone)

    Functioning human pancreatic cells after they’ve been transplanted into a mouse. (Image: Saiyong Zhu, Gladstone)

  • Challenges of stem cell-derived diabetes treatments. At this year’s Ogawa-Yamanaka Stem Cell Award ceremony Douglas Melton, a well-renowned diabetes researcher from Harvard, spoke about the main challenges for developing stem cell-derived diabetes treatments. The first is the need for better control over the methods that make beta cells from stem cells. The second was finding ways to make large quantities of beta cells for human transplantation. The last was finding ways to prevent a patient’s immune system from rejecting transplanted beta cells. Melton and other scientists are already working on improving techniques to make more beta cells from stem cells. As for preventing transplanted beta cells from being attacked by the patient’s immune system, Melton described two possibilities: using an encapsulation device or biological protection to mask the transplanted cells from an attack.

Progress to a Cure: Clinical Trials for Type 1 Diabetes

Speaking of encapsulation devices, CIRM is funding a Phase I clinical trial sponsored by a San Diego-based company called ViaCyte that’s hoping to develop a stem cell-based cure for patients with T1D. The treatment involves placing a small encapsulated device containing stem cell-derived pancreatic precursor cells under the skin of T1D patients. Once implanted, these precursor cells should develop into pancreatic beta cells that can secrete insulin into the patient’s blood stream. The goal of this trial is first to make sure the treatment is safe for patients and second to see if it’s effective in improving a patient’s ability to regulate their blood sugar levels.

To learn more about this exciting clinical trial, watch this fun video made by Youreka Science.

ViaCyte is still waiting on results for their Phase 1 clinical trial, but in the meantime, they are developing a modified version of their original device for T1D called PEC-Direct. This device also contains pancreatic precursor cells but it’s been designed in a way that allows the patient’s blood vessels to make direct connections to the cells inside the device. This vascularization process hopefully will improve the survival and function of the insulin producing beta cells inside the device. This study, which is in the last stage of research before clinical trials, is also being funded by CIRM, and we are excited to hear news about its progress next year.

ViaCyte's PEC-Direct device allows a patient's blood vessels to integrate and make contact with the transplanted beta cells.

ViaCyte’s PEC-Direct device allows a patient’s blood vessels to integrate and make contact with the transplanted beta cells.


Related Links: