Radioimmunotherapy for Lympho... Video Transcript

Participants

, Robert O. Dillman M.D., F.A., Leo I. Gordon MD, Stephanie Ann Gregory M.D., Russell J. Schilder MD, Carol L. Kornmehl MD, FACRO

Summary

Harnessing radiation to attack cancer cells is the hottest new therapy in lymphoma treatment. But doctors are still determining when is the best time to use radioimmunotherapy. Find out how this therapy fits into lymphoma treatment plans.

Webcast Transcript

ANNOUNCER: The newest treatment for non-Hodgkin's lymphoma, Radioimmunotherapy continues to spark a great deal of discussion among doctors. This treatment harnesses the cancer targeting ability of monoclonal antibodies to attack cancer cells.

LEO I. GORDON, MD: We already have antibodies, which we can target to malignant cells. Radioimmunotherapy adds to that by attaching radioactive particles or radioactive substances to that antibody so that we can do the immunotherapy, but with an added kick, if you will.

ANNOUNCER: Chemotherapy and now targeted therapy have been the standard of care for people with many types of lymphoma.

LEO I. GORDON, MD: For aggressive lymphomas I think the gold standard is still the use of a combination of chemotherapy drugs called CHOP or Cytoxan, Adriamycin, vincristine and prednisone. For low-grade lymphomas. I would still say the gold standard is still the use of single agent chemotherapy agents, drugs such as chlorambucil or Cytoxan and then possibly combinations with Cytoxan, vincrinstine and prednisone. And then over the past several years more and more studies have shown that the addition of Rituxan, adds to the treatment.

ANNOUNCER: The drug Rituxan or rituximab is a monoclonal antibody that is non-radioactive. But the monoclonal antibodies used in radioimmunotherapy Zevalin and Bexxar, contain an added radioactive component. One of the first questions surrounding the use of radioimmunotherapy is who are the best candidates for it?

LEO I. GORDON, MD: It's primarily patients with what we call low-grade or indolent lymphomas.

STEPHANIE ANN GREGORY, MD: The FDA has actually approved Zevalin for rituximab refractory patients which means that they have been exposed to Rituxan perhaps did not respond to that, and then, they are a candidate for Zevalin.

ANNOUNCER: But before a patient can get radioimmunotherapy, they must be carefully examined.

LEO I. GORDON, MD: Patients first of all have to have some staging tests. CAT scan is routine. Patients have to have a bone marrow. What we're afraid of is that when the marrow is more than 25 percent involved, you'll see longer duration of low white count and low platelet count. They need blood tests to be able to be sure that the platelet count is adequate and the white blood count is adequate before they start.

ANNOUNCER: As a treatment radioimmunotherapy is given just one time. First the patient is given an intravenous injection of the rituxan as a pre-dose. Then zevalin is administered. Once in the body it binds to the surface of lymphoma cells and delivers a dose of radiation. Doctors are discovering improved response rates when using this therapy.

LEO I. GORDON, MD: We're seeing an overall response rate of about 80 percent and a complete response rate of about roughly 30 percent , maybe even a little bit higher, even 30 percent . And then there's another group of patients who are considered to be partial responders. This means because the disease doesn't completely disappear by CAT scan but who remain stable. So many patients who are complete responders and a certain number of patients who are partial responders, the Zevalin is the last treatment they have and they're doing quite well. And if you look at patients who have had Rituxan already, and either never responded to the Rituxan or responded but it only lasted for less than six months, the overall response rate is about 74, 75 percent and again the complete response rate is about 30 percent .

ROBERT O.