The new therapy comes from Duke University (the laboratory of Dr. Ashutosh Chilkoti) and the reason that the single injection lasts for so long is due to a controlled-release mechanism, whereby the drug is slowly released to the target site. The new medication is intended for type 2 diabetes.
Diabetes mellitus type 2 refers to a long term metabolic disorder that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, and unexplained weight loss. Injecting insulin is an essential part of the daily regime for many diabetics.
Many current treatments for type 2 diabetes involve the use of a signaling molecule termed glucagon-like peptide-1 (GLP1). This molecule signals to the pancreas to release insulin, which controls blood sugar. The limitation of this treatment is the peptide having a short half-life resulting in it being cleared from the body fairly rapidly. This means, in the major cases of diabetes, a daily injection for patients.
The new therapy lasts for far longer and the basis of the injection is a biopolymer. With this, the researchers fused GLP1 with synthetic microspheres and biomolecules like antibodies. This involved developing a heat-sensitive elastin-like polypeptide (ELP) in a solution that can be injected into the skin through a standard needle.
The slow-release mechanism is based on the drug, when it is injected, reacting with natural body heat to form a biodegradable gel-like “depot”. This structure proceeds to slowly release the drug as it dissolves.
The drug is the drug is synthesized inside Escherichia coli bacterial cultures instead of mammalian cells, which reduces the cost and allows for the possibility of large scale production should the process be commercialized.
As things stand with the drug development, the new process has been tested on primates with human trials set to take place soon. If these trials are successful then the outcome could be a once-a-month injection to replace daily insulin shots for those with type 2 diabetes. The research on primates showed effectiveness current stands at 14 days.
The new approach has been published in the journal Nature Biomedical Engineering. The research is titled “An Injectable Depot of Glucagon-Like Peptide-1 Fused to a Thermosensitive Polypeptide With Zero-Order Release Kinetics Provides One Week of Glucose Control.”
