After more than two decades of dashed expectations, the field of gene therapy appears close to reaching a milestone: a regulatory approval.

The European Medicines Agency has recommended approval of a gene therapy to treat a rare genetic disease, according to the agency’s Web site.

If the European Commission follows the advice, as it usually does, this would be the first regulatory approval of a gene therapy drug in the Western world. That could give a boost to the field, which at times has struggled for credibility and financing.

An approval ‘is really potentially going to change the way the field is looked at,