Gene Delivery Adds to Bird-Flu Arsenal?

U.S. biotech firm BioDelivery Sciences International said Wednesday its Bioral gene-delivery system cuts flu virus levels in mice 200-fold.

The company said it has been testing its Bioral delivery technology to deliver a siRNA therapeutic in a mouse model infected with influenza, adding that the particular siRNA used in the study targets the same gene segments as those found in the deadly avian influenza (H5N1).

The siRNA therapeutic is packaged for delivery in a nanocrystalline structure called a cochleate, made from naturally occurring substances, the company said.

In the mouse model a single intranasal dose of encochleated siRNA administered four hours after influenza exposure appeared to cut the viral load in the lung by 200 times, BDSI said.

The company said it also tested in the rodent model an intravenous version of the technology, noting that the encochleated siRNA was approximately 25 times more effective in reducing the virus using intravenous delivery, compared to naked or non-encochleated siRNA.

The siRNA technology works by triggering a cellular response that destroys molecules that produce virus proteins within the cell, preventing the virus from replicating and causing disease, BDSI said.

Encochleated RNAi formulations represent an exciting and promising new area of medical therapeutics, said Raphael Mannino, executive vice president and chief scientific officer of BDSI. Therapeutic siRNAs have the potential to transform the pharmaceutical industry by reducing the considerable time and expense needed in order to find traditional small molecule drugs.