The discovery of a new peptide could improve treatments for diabetic macular edema and diabetic retinopathy, as well as other degenerative retinal diseases.
US researchers at John Hopkins University School of Medicine say this injectable peptide could last longer when compared to current treatments.
Vascular diseases such as edema and retinopathy can lead to central vision loss as abnormal blood vessels grow into tissues at the back of the eye. This can cause leakage in the eye.
Current treatments include vascular endothelial growth factor (VEGF) drugs, such as aflibercept (marketed as Eylea), which is injected directly into the eye every four to six weeks in most patients. Eylea was approved for treatment in people with diabetes by the European Medicines Agency in 2014.
“These frequent visits can become a burden for patients due to the discomfort and small risk of each injection and, for some patients, because their vision is not good enough to drive to appointments,” said Jordan Gree, Ph.D., associate professor of biomedical engineering at the Johns Hopkins University School of Medicine.
To address the frequency in which these drugs are administered, the researchers tested a peptide (a compound of two or more amino acids) in mice to see if it was more effective at suppressing damage that currently used treatments.
The peptide, called AXT107, was found to be particularly effective at suppressing new vessel growth when combined with aflibercept.
In another study, mice treated with AXT107 had less new vessels compared to mice treated with a control peptide, with AXT107 also causing regression of already established new vessels.
Study author Dr Peter Campochiaro said: “Unlike the current standard, which only targets the VEGF protein, our peptide also binds to cellular receptors that recognize growth factors like VEGF. The cellular signals for vascular growth are blocked in many ways by the peptide, allowing it to have a stronger effect.”
The study team say that AXT107’s longevity is due to its natural aggregation to form a small, gel-like structure within the eye that holds the peptide inside for longer.
They now plan to encapsulate the peptide into biodegradable microparticles which could release the drug steadily over many months.
Green added: “The peptide can be manufactured for clinical use and scaled up very easily. In addition to potentially improving treatment for patients, combined with needing less frequent clinical visits, this could bring down the cost of treating these diseases.”
The findings appear online in the journal Science Translational Medicine.

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