STEPHEN SCHUSTER, MD: What's been done by investigators to improve on the efficacy of antibodies in killing cells has been to use them as vehicles for delivery of radiation directly to the tumor sites. What radioimmunotherapy allows us to do is to deliver radiation to a patient that treats the entire body without exposing normal tissues to radiation. So you can treat somebody with multifocal or multisite disease.
ANNOUNCER: Radioimmunotherapy is given to a patient over about a week's time in comparison to chemotherapy, which takes several weeks.
Initially the patient receives a dose of the antibody without radiation attached, to kill stray cancer cells outside of the tumor. Next, the patient receives a low dose of a radiolabeled antibody. This allows doctors to see exactly where the tumor sites are.
ROBERT DILLMAN, MD: The unlabeled antibody is given to improve the distribution of the radiolabeled antibody so that you get the optimum distribution for treatment.
ANNOUNCER: A week later, the patient receives a high dose of the radioactive antibody that concentrates the radiation directly at the tumor site.
STEPHANIE GREGORY, MD: It's day one of treatment to essentially give a small amount of the radioactive material and then it is followed a week later with a definitive dose of radiation, so it is over within a week.
ANNOUNCER: Results are what matters and clinical studies indicate that radioimmunotherapy can be very effective.
STEPHEN SCHUSTER, MD: When patients are on clinical trials or under therapy, they can either have a complete response, which means disappearance of all disease; they can have a partial response, which -- which we describe as greater than 50% shrinkage of their disease.