Experimental Cancer Treatment Offers Hope

Now we turn to what is being hailed as a breakthrough in the fight against cancer. A small group of pioneers sending a big ray of hope. An experimental treatment that appears to stop cancer cells in... See More

Now we turn to what is being hailed as a breakthrough in the fight against cancer. A small group of pioneers sending a big ray of hope. An experimental treatment that appears to stop cancer cells in their tracks in some people. And abc's dr. Rich about bard besser tells us about the big news today. Reporter: David asponte was out of options. He was being treated for acute lymphocytic leukemia, a rare and often fatal disease in adults. When chemotherapy failed, doctors turned to an experimental treatment. Robin roberts went to visit him last december. I think I am on the right road, I think I am on the right road. Reporter: Doctors took out millions of david's disease-fighting white blood cells, then used a retrovirus, which is great at getting into human immune systems to change those cells to targeted cancer fighters. David's cells went back in and destroyed the cancer like a living drug. The first patient to have similar experimental treatment was 7-year-old emma whitehead who went through the procedure last year and now is in complete remission. She has a ton of energy. She's doing wonderful right now. Reporter: Researchers now report on the safety of this treatment in five more patients. What we saw just blew us away the cancers went away in a matter of weeks even days. Reporter: Days? Days in one case. Reporter: That one case was david. The treatment almost killed him but after eight days in a coma, not a trace of cancer. He went on to a bone marrow transplant. I will take every day that i can. Make it count. Got it. Reporter: While fewer than 3,000 patients have the type of leukemia. The approach has a much broader reach. If offers hope that it can also work in bigger tumors such as colon cancer, breast cancer, and lung cancer. Hope tonight. So, rich, what's next? Reporter: Well, I mean, i think this approach is incredibly exciting. This was a small safety study. They're enrolling more people in that. They're going to do a longer study looking at benefits and risks. Other researchers are saying, can you use this for any type of cancer? It's early days, but this kind of approach is so promising. And it is so good to hear about dave. Reporter: That's right.