Betalutin (RIT) Trial for FL Has Been Stopped

The company that makes the RadioImmunoTherapy (RIT) treatment called Betalutin has decided to stop its phase 2 trial for third line Follicular Lymphoma treatment. I'm a little sad about it.

Sad, but not really surprised -- I've been saying for a while that I thought Betalutin would face some challenges. RIT treatments just require too much work in the U.S. But what surprised me was that its most recent results showed good safety and decent effectiveness, but "decent" isn't good enough.

A little background, to remind you, since I haven't written about Betalutin in a while:

RadioImmunoTherapy treatments are kind of a combination of monoclonal antibodies (like Rituxan) and radiation therapy. Radiation is not common in Follicular Lymphoma and other blood cancers because it works best when the cancer cells stay still, as they do in solid tumors like lung cancer or colon cancer. Blood cancer cells move around through the blood constantly. A beam of radiation won't work. 

So what if you could take the radition directly to those moving cells? That's what RIT does. It takes something like Rituxan, which seeks out B cells by attaching itself to a protein on their surface, but it adds a little bit of radiation to the Rituxan. So you have a package of radiation delivered right to the cancer cell. 

In theory, it means fewer side effects, since the radiation goes directly to the cancer cell. And it means it's effective, for the same reason -- the treatment has a specific target. 

And RIT is indeed effective. In the past, two RIT treatments were approved by the FDA for FL -- Zevalin and Bexxar. However, in the U.S., rules for treating patients with RIT are complicated. Because it is radioactive, it requires special training, so regular oncologists can't give it patients (unlike traditional chemo or immunotherapies). With so many other effective options, most oncologists don't send patients to RIT specialists without some really compelling reason.

So RIT is use much less often than it should be, given how safe and effective it is. Bexxar wasn't used often enough to stay around, and it was discontinued in 2013. Zevalin is still around, and researchers continue to provide data that shows it is an excellent option (most recently in April). But it is still used much less frequently than it should be.

So, as I said, I'm not surprised that Betalutin isn't going to be an option for us (though the manufacturer is looking at other ways to offer it, maybe in combination with other treatments). Only about 33% of the 109 patients in the trial had a response that lasted more than 6 months. That's not great, especially when compared to CAR-T and bi-specifics. 

So why am I a little sad about this? It's personal, I guess. Zevalin was approved in 2009, the year after I was diagnosed. I think it was probably the first FL treatment to get FDA approval during the time I started really paying attention to that kind of thing. I know a couple of people who had Zevalin early on and who had great success -- over 15 years in remission. So I've always hoped that RIT would catch on.  But I can't imagine any one else will make an attempt to bring RIT to the market at this point. The field has moved on.

One last important point. It seems like I've been writing a lot lately about treatments have not been successful . That's true. But I don't think that means that more treatments are failing. If anything, it means that there are more high profile treatments that are being talked about early on in the trial process, and that I am writing about them. Remember, less than 10% of cancer treatments ever make it to a phase 3 trial. The great majority of them don't show enough effectiveness or safety in phase 2, phase 1, or (especially) pre-trial results to move forward.

My point is, there are still lots of treatments available to us, and lots more to come. 

I'll move on from my little bit of sadness. There is so much more to come to be excited about. And I'll keep sharing what I learn.