Starting Targeted Therapy For... 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

Targeted therapies, those that hone in on cancer cells, are the latest weapons used in the treatment of non-Hodgkin's lymphoma. Learn about the different targeted therapies available and how they are selected.

Webcast Transcript

Announcer: One of the most significant developments in cancer treatment today is the use of targeted therapies. It has now become important in the treatment of non-Hodgkin's lymphoma.

Stephanie Ann Gregory, MD: A targeted agent is something that actually goes in and hits a cancer cell and preserves the normal cells.

Leo I. Gordon, MD: Rituxan is the major targeted therapy for non-Hodgkin's lymhoma. It targets the CD20 antigen on the surface of B-cells.

Announcer: In targeting malignant lymphoma cells, Rituxan is a non-radioactive antibody. It's used alone or combination with the standard of care for lymphoma-chemotherapy.

Leo I. Gordon, MD: There are some immediate side effects with Rituxan. People can get fevers. They can get a tickling sensation in their throat. They can get short of breath. So you need to infuse it fairly slowly.

Announcer: But the newest targeted therapy, radioimmunotherapy, provides the added benefit of radiation.

Robert O. Dillman, MD, FACP: Radioimmunotherapy at the present time consists of monoclonal antibodies that have radioisotopes attached to them so that you can target the radiation to whatever the antibody binds to.

Announcer: There are two drugs currently used in radioimmunotherapy, Zevalin and Bexxar. Each uses different radioisotopes with unique characteristics.

Leo I. Gordon, MD: Zevalin utilizes radioactive yttrium and has a very short half-life. It's short half life mean that it can be given as an outpatient. There's lots of studies now showing that it's fairly safe to give, safe for the patient and especially also safe for family members and health care workers. Bexxar utilizes I-131. The advantage of I-131 linked to antibody is that you can get a pretty good sense of where the radioactivity is going just from one dose. The downside of I-131 is that it's got a fairly long half-life so that patients, at least in many states around the country still need to be hospitalized.

Announcer: Many doctors today are considering how to choose between the different targeted therapies, and where to position them within a treatment regimen.

Robert O. Dillman, MD, FACP: Is it best to use Rituxan by itself? Is it best to use it in combination with chemotherapy? Is it best to use Rituxan first, then chemotherapy? Chemotherapy first, then Rituxan? And we don't really have clear answers on that. In terms of Rituxan vs. the radioimmunotherapy, I think at the present time you definitely would always want to pick Rituxan first. The reason for that is its safety profile seems to be superb. It's a very well tolerated agent and some patients get remarkably good responses with it that last for years and years.

Announcer: In selecting a treatment, particularly radioimmunotherapy, doctors must consider which patients are most appropriate.

Robert O. Dillman, MD, FACP: If somebody fails Rituxan, radioimmunotherapy is an option. The ideal patient, however is someone who previously has responded to Rituxan and the response has gone away rather than somebody who just got Rituxan.

Stephanie Ann Gregory, MD: The criteria for delivering radioimmunotherapy is essentially that you must not have a bone marrow that has involvement with lymphoma of more than 25 percent of the bone marrow.

Leo I. Gordon, MD: When the radioactivity gets into the marrow in large amounts, as it would when you have the marrow extensively involved with lymphoma, then the toxicity is going to be greater.

Stephanie Ann Gregory, MD: Patients are also not candidates for radioimmunotherapy if they have had a stem-cell transplant.