by Ross Bonander
In 2002, the FDA approved Zevalin (ibritumomab tiuxetan) as a treatment for patients with relapsed or refractory, low-grade or follicular B-cell non-Hodgkin's lymphoma. At that time, Zevalin became the first conjugated antibody for the treatment of non-Hodgkin's lymphoma, and the first radioimmunotherapy agent for the treatment of NHL.
Then, this past September the FDA gave expanded approval to Zevalin for the treatment of patients with previously untreated follicular non-Hodgkin's Lymphoma (NHL) who achieve a partial or complete response to first-line chemotherapy.
How does it work?
Here's the Zevalin therapeutic regimen, as the patient can expect it to go (minus most of the biochemistry).
Treatment: Day 1
You begin with an IV infusion of rituximab (this could take 4 hours), administered by your hematologist or oncologist.
Within 4 hours of completing this infusion, you will be taken to your treatment facility's nuclear medicine or radiation oncology department, where you will be given In-111 Zevalin (an IV injection lasting around 10 minutes).
Treatment: Day 3 or 4
48 to 72 hours following the In-111 Zevalin infusion, you will undergo an imaging study (scan) using a gamma camera. The reason?
Because In-111 Zevalin produces gamma emission (similar to the radiation used in x-rays). Your doctor can trace the In-111 Zevalin throughout your body (the amount of radiation received is considered very low; side effects from this radiation are unlikely). Your doctors are looking to see a particular distribution pattern of In-111 Zevalin within your body, and they may require additional scans. If what they see in terms of distribution pattern is not what they expect, it's possible you will not be given the Y-90 Zevalin.
Treatment: Day 7, 8, or 9
You receiver a second rituximab infusion (again, it could take up to 4 hours). Within 4 hours of this, you will be taken to your treatment facility's nuclear medicine or radiation oncology department.
There, you will be given your Y-90 Zevalin treatment (an IV injection lasting around 10 minutes).
Is it effective?
The Zevalin therapeutic regimen lasts at most 9 days, requires two 4-hour infusions of rituximab, two 10-minute infusions of Zevalin, and at least one imaging scan.
According to a Phase-3 study involving 414 patients with follicular lymphoma, when the Zevalin therapeutic regimen is used as part of first-line treatment involving chemotherapy, Zevalin "significantly improved the median progression-free survival time from 18 months (control arm) to 38 months (ZEVALIN arm)." Click HERE for more details of this study and the efficacy of the Zevalin therapeutic regimen.
What is In-111 Zevalin?
In-111 Zevalin consists of a monoclonal antibody (Zevalin) combined with a low dose of the radioisotope Indium-111. The Zevalin seeks out and attaches itself to the CD20 antigen that can be found on the surface of both malignant and normal B-cells. The Indium-111 is used for screening purposes: Doctors want to see that cancerous cells are being properly targeted, and the Indium-111 allows them to see this.
What is Y-90 Zevalin?
Y-90 Zevalin consists of a monoclonal antibody (Zevalin) combined with the radioisotope Y-90. Inside your body, the Zevalin seeks out and attaches itself to the CD20 antigen found on the surface of both malignant and normal B-cells. Meanwhile, the radioisotope Y-90 creates a type of radiation called beta emission, and these emissions are powerful enough to damage cancer cells (and possibly some healthy cells).
What is rituximab?
Rituximab (marketed as Rituxan) is a monoclonal antibody used to treat indolent and follicular B-cell Non-Hodgkin’s Lymphomas (NHL). It works by attaching itself to the CD20 antigen found on malignant and normal B-cells, which in turn activates the body’s immune system to attack and kill the cells.
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