Zevalin: Real-World Success for Follicular Lymphoma

First, a quick colonoscopy update: I had a biopsy during the procedure, and it came back benign. Right after the procedure, the doc said everything looked good, but now it's official.

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Now, back to Follicualr Lymphoma.

Nice article from about a month ago in Clinical Lymphoma, Myeloma, and Leukemia called "Real World Long-term Follow-up Experience with Yttrium-90 ibritumomab tiuxetan in Previously Untreated Patients with Low-Grade Follicular Lymphoma and Marginal Zone Lymphoma."  

Yttrium-90 ibritumomab tiuxetan is the scientific name for Zevalin, a type of RadioImmunoTherapy (RIT). The last time I wrote about RIT was in January. It doesn't get a lot of attention these days, except for Betalutin (which you can read about in the link). To remind you: Radiation is an effective treatment for lots of cancers, but not blood cancers, since blood cancer cells move around too much for radiation to work. So along came RIT. It basically works by taking a little bit of something like Rituxan, which can find and attach itself to a blood cancer cell, and adding a tiny bit of radiation to it. So when the Rituxan finds a cancer cell, it can deliver the radiation right to it. 

Zevalin was one of the first two types of RIT to be approved for Follicular Lymphoma. It was very successful in clinical trials, and I know two people who have had very long remissions after Zevalin. The problem has been, at least in the U.S., that Zevalin is complicated to deliver. Not because of the way the treatment works, but because there are rules in place for who is allowed to give the treatment, since working with radiation requires special training. So Zevalin has never been a popular treatment -- not as popular as something that is so effective.

Because it has been a fairly under-used treatment, there hasn't been much done in clinical trials, where records are kept to show how successful a treatment has been. This study is a "real world" study, that is, looking at patients outside of clinical trials. 

The results are great.

Because this isn't a trial, the researchers look at records of patients who had Zevalin as a first treatment, and determine how well they did on the treatment. The study looked at 51 patients, with 41 of them diagnosed with FL. The median follow-up was a little over 5 years. Of those patients, all 51 had a response to Zevalin, with 94% of them getting a Complete Response, which is pretty amazing. (Remember, about 70% of CAR-T patients had a response in early trials, though that number is going up.) After 2 years, about 59% of those patients continued to have a CR (it's about half that in CAR-T). And about 25% of them had a long-term CR of over 7 years.

Those are pretty great numbers for effectiveness. As for safety, again, the numbers are very good. More serious side effects (grade 3 or higher) for thrombocytopenia (low platelets) was 47%; neutropenia (low white blood cells) was 37%, and anemia (low red blood cells) was just 4% . Sometimes radiation treatments can cause other blood cancer likes myelodysplasia or acute myeloid leukemia, but none were found in this group. 

So, overall, Zevalin continues to be a really good treatment, with short-term and long-term effectiveness, and manageable side effects for most patients.

I'm not sure it will ever be a popular choice, but it's still there for us. And maybe Betalutin will turn out to be just as effective, but with some incentive to make it easier to administer. In the meantime, we still have some other choices, which is a good thing.