Sunday, November 14, 2010

Bexxar Problems

I've written a lot about RadioImmunoTherapy (RIT), particularly one of the two types, Zevalin. I don't mean to ignore the other type of RIT, Bexxar, but there's been so much more news about Zevalin in the past few years that it's been easy to ignore Bexxar.

Which brings us to a problem: drug maker GlaxoSmithKline announced last week that it will severely cut back on its production of Bexxar, which will make it very difficult for some patients to get access to it.

This is not good. Bexxar and Zevalin work in similar ways, but they are pretty different -- different enough that losing Bexxar will create potential problems for lots of patients. For example, both types of RIT are essentially monoclonal antibodies with a bit of radiation attached to them, so when they bind to a specific protein on a lymphoma cell, the radiation can zap it. (Here are some other differences between Bexxar and Zevalin, courtesy of

Here's where the problem lies: Zevalin is basically radioactive Rituxan, currently the most commonly-used monoclonal antibody. But many patients who use Rituxan alone and as part of chemo can become resistant to Rituxan. So there's a chance that they will be resistant to Zevalin, too. Having another RIT option like Bexxar may save them (as it has saved many others) when Rituxan-containing treatments stop working.

Naturally, the NHL community is up in arms about this. GSK has every right to cut down or stop production if people aren't using Bexxar. However, GSK hasn't done a whole lot to market Bexxar, either, so NHLers are feeling a little betrayed. And they've become very vocal about this. For example, it didn't take too long to reach 1200 signatures on a petition to GSK to save Bexxar.

I think they're unlikely to change their minds. RIT, for all kinds of reasons I've discussed here in the past, just isn't widely used, despite its well-documented successes. I think what we can hope for is that GSK sells Bexxar to someone who's more willing to push it. That's exactly what's happened to Zevalin, and sales picked up as a result.

Keep your fingers and lymph nodes crossed....

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