John Morris, M.D.
Professor of medicine and director of the UC Cancer Institute’s Phase I/Experimental Therapeutics Program
—as told to Lisa Murtha
We have one patient, a young ex-military person who had a refractory, unusual cancer. [Drug developer EpicentRx] said…could we get this [new drug] approved as a single patient exemption? That’s where you go to the FDA and say: “Listen, we have a serious situation here, a crisis situation; we would like approval to treat a single patient with this experimental drug.” We had to go through a lot of committees at the university and the Food and Drug Administration. That was all approved in April. He is the only person and we are the only place doing this particular treatment, the Safety Net Trial.
[The Trial] uses something called the PSV2 virus, developed by EpicentRx; this is sort of a cross between gene therapy and immunotherapy. The idea is they take a patient’s tumor, do genetic sequencing, and pull out mutations of the tumor. Now these mutations should be recognized as foreign to the body and [the body] should help reject the tumor, but there’s lot of tricks tumors use to get around that. So these mutations, the ones [scientists] feel are the strongest, [have been] encoded into what’s called an adenovirus, a common virus that causes sore throats and colds and is relatively safe. The virus is programmed to start replicating in tumor cells and not normal cells, so the expression of these antigens triggers a stronger immune response and destroys cancer cells.
Other than experiencing a high fever and chills the first time he got treated, the patient really had no serious side effects, and clinically has remarkably improved. He was losing weight and having severe pain; both of those have been reversed. What’s remarkable is that the injected lymph nodes have become what we call necrotic—dead tissue—so the virus appears to be doing what it was designed to do: It disrupts and kills the cancer cells in the lymph nodes. When you get this type of response, the immune system kicks in and we hope that other areas that we are not injecting are then attacked by the immune system, treating other sites of the disease.
This is essentially a vaccine strategy, once you have the disease already. The fact that there were no serious side effects actually bodes well, but remember—this is a single patient. It’s obviously going to need to be tested on more patients. We are cautiously optimistic. Hopefully, within a few months [this therapy] will be available to other patients. These viral approaches are really the wave of the future.