A better microscope traps gene vector

One of the major safety issues with gene therapies is integration of foreign DNA into the germline of patients, where it would cause problems in future generations. Using a test that is much more sensitive than previously used PCR tests, Avigen Inc. has detected vector DNA in the semen of the first patient given a hepatic artery infusion of its Coagulin B. But while a more sensitive test increases confidence in safety, the clinical implications of the results are not completely clear.

As a result of the finding announced last week, AVGN suspended a Phase I/II trial of its Coagulin B adeno-associated virus vector carrying a gene for human clotting Factor IX in hemophilia B patients. ...