Earlier this year we wrote about the promising results of a phase 1 clinical trial aimed at replacing the deteriorating cells in the retinas of people suffering from age-related macular degeneration- one of the leading causes of blindness worldwide for people over 50. Now there’s even more good news! Highlighted in a news story on the UC Santa Barbara (UCSB) website, researchers are continuing to make progress in their bid to secure approval from the Food and Drug Administration for the life-changing treatment.
Through the collaborative efforts of researchers at UCSB, University of Southern California and California Institute of Technology, a stem cell-derived implant using cells from a healthy donor was developed. The bioengineered implant, described as a scaffold, was then implanted under the retina of 16 participants. If the implant was to work, the new cells would then take up the functions of the old ones, and slow down or prevent further deterioration. In the best-case scenario, they could restore some lost vision.
The first sets of trials, funded by the California Institute for Regenerative Medicine (CIRM), concentrated on establishing the safety of the patch and collecting data on its effectiveness. Parting ways with old practices, the participants in the trial were given just two months of immunosuppressants whereas in the past, using donor cells meant that patients often had to be given long-term immunosuppression to stop their body’s immune system attacking and destroying the implanted cells. The team found that after two years, the presence of the patch hadn’t triggered other conditions associated with implantation, such as the formation of new blood vessels or scar tissue that could cause a detachment of the retina.
Even more importantly, they found no sign of inflammation that indicated an immune response to the foreign cells even after the patient was taken off immunosuppressants two months post-implantation. “What really makes us excited is that there is some strong evidence to show that the cells are still there two years after implantation and they’re still functional,” said Mohamed Faynus, a graduate student researcher in the lab of stem cell biologist Dennis O. Clegg at UCSB.
Having passed the initial phase, the team of researchers now hopes to begin phase 2 of the trial. This time, they are aiming to more specifically assesses the effectiveness of the patch in participants. Looking even farther ahead, the Clegg Lab and colleagues are also exploring combining multiple cell types on the patch to treat patients at varying stages of the disease.
In addition, there have also been improvements made to extend the shelf life of the patch. “Cryopreservation of the therapy significantly extends the product’s shelf-life and allows us to ship the implant on demand all over the world, thus making it more accessible to patients across the globe,” said Britney Pennington, a research scientist in the Clegg Lab.