Thursday, July 25, 2013

Promising RIT for Follicular Lymphoma?

There's a new cowboy in RITville.

(OK, that metaphor isn't my best. I'm on vacation.)

There's a new version of RIT that may be available at some point. Results from an early clinical trial look good.

RadioImmunoTherapy (RIT) is a fairly effective, but fairly underused type of treatment for NHL. Right now, there are two versions of RIT available, Bexxar and Zevalin. They are both effective, and have some differences between them that make the choice of one or the other better for some patients. (Lymphomation does an excellent job of comparing the two, which isn't surprising, because they do an excellent job at pretty much everything.) RIT works by providing radiation to lymphoma cells. Because blood cancer cells are moving targets, traditional radiation treatments don't work. So RIT treatments use something that can find and attach themselves to cancer cells (like Rituxan) and have that molecule carry a tiny dose of radiation, delivered directly to the cancer cell. Pretty cool system.

The current issue of the Journal of Nuclear Medicine reports on the results of a clinical trial for a version of RIT that uses luteum-177, added to Rituxan, as its delivery method. Lu 177 differs from the other RIT types because it doesn't penetrate tissue as deeply (and therefore won't travel too far beyond the targeted cancer cells, sparing more healthy cells).

The purpose of this trial was to determine the best dosage for this treatment, and it seems like they got decent results -- about 52% of patients got a response (29patients overall; 6 had a complete response and 9 had a partial response).

However, the results for the group of patients with Follicular Lymphoma were particularly good (it "appeared to have striking activity in follicular lymphoma," said the authors). of the 11 patients with FL, 9 had a response, for an 82% response rate. Excellent.

It's an early study, so it will need to go through more steps, and recruit more patients for tests. And then, there's the whole issue of whether or not it will be practical -- that is, whether or not it will run into the same problems as Zevalin and Bexxar, with their reimbursement and logistical problems. But maybe this will be the one that gets some attention and forces a re-evaluation of the uses of RIT.

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