Biotech drug developer Targeted Genetics Corp. said Wednesday it has been issued an additional patent related to its adeno-associated virus vector technology.

The announcement sent shares of Targeted Genetics up 6 cents, or 3 percent, to $2.01 in morning trading on the Nasdaq. Over the past year, Targeted Genetics shares have traded between $1.71 and $7.

The patent describes the use of adeno-associated virus vectors that are more efficient for expression of therapeutic genetic constructs, Targeted Genetics said.

The company is developing treatments for inflammatory arthritis, HIV/AIDS and other acquired and inherited diseases.