Initial studies reported in October 1996 have been very promising. In tissue culture the E1B-negative adenovirus does not grow in healthy skin cells, but does grow in a wide variety of tumor cells, including colon and lung cancer cells. Initial human trials have been started. While E1B-deficient adenovirus offers great promise as a therapy for a wide range of cancers, including most lung cancers, a significant technical hurdle remains. Recall that the initial animal tests were done on mice with no immune system.
Humans have active immune systems.
In cancer patients the adenovirus therapy may be neutralized by the patient's immune system before the virus has a chance to do any good, simply because most people have had adenovirus colds in the past and so can be expected to carry antibodies directed against adenoviruses. In these people, such antibodies might attack any E1B-deficient adenovirus introduced to fight cancer. Anticipating this problem, investigators are exploring alternative viruses that would not provoke an immune response. Molecular therapies such as those described here are only part of a wave of potential treatments under development and clinical trial.