In a clinical trial, researchers evaluated the safety of using a gene vector, in this case an adeno-associated virus, to deliver a corrective gene to patients who are unable to produce a protein essential for health called alpha-1 antitrypsin.
“The primary endpoint in the trial was to see whether it was safe to give patients this gene transfer vector and then to try to begin to see if we could get the dose into a range where we would begin to replace the missing protein in the blood,” said Terence Flotte, pediatrician, geneticist and microbiologist with UF’s College of Medicine.
“We found that we can use this agent safely and we also saw evidence in the patients’ blood that the higher doses successfully introduced the vector DNA. In one patient we saw evidence for a very brief period that some of the alpha-1 protein was being produced, but not at a high enough level to be beneficial.”
Alpha-1 deficiency can, in some patients, lead to emphysema and cirrhosis, both progressive diseases that can be fatal.
Researchers said that the next step is to test the therapy with a different version of the adeno-associated virus.
“We have another version of the virus that appears in animal studies to be close to a thousand fold more potent at making protein,” Mr Flotte said. “So the next trial is to use the new version of the virus and take patients through a similar range of doses, in a very similar scheme, and see if we can maintain the safety while pumping up the efficiency of the protein production.”