No More Tazemetostat

The news came out this week that the makers of Tazemetostat will no longer offer this treatment to patients, including patients with Follicular Lymphoma. There are too many concerns about patients developing new, different cancers.

They made an announcement about a month ago that they were stopping a clinical trial that was testing it, and now they have decided to just pull it from the market completely.  

Tazemetostat is an EZH2 inhibitor. It works by inhibiting or stopping an enzyme called EZH2, or Enhancer of Zeste Homolog 2." This enzyme is controlled by the EZH2 gene. EZH2 keeps tumors growing, so when it's not doing its job, it needs to be inhibited -- stopped by Tazemetostat. About 20% of FL patients have an issue with their EZH2, though it can also be effective on patients that don't have that particular mutation.  

Tazemetostat was approved by the FDA in 2020 based on its ability to help that 20% of FL patients -- it was the first treatment that successfully helped that group of patients. The FDA approval was accelerated, meaning it was approved based on a small phase 2 clinical trial, rather than the usual, larger phase 3 trial. The accelerated approval, as always, is based on continuing research. A larger phase 3 confirmatory trial must be run to make sure the treatment is as effective and as safe as the smaller trial suggested.

Accelerated approval can be great. But sometimes the phase 3 trial that comes after approval shows some problems. And in this case, that problem was that the treatment may be causing secondary cancers. I haven't seen anything about how many patients developed the new cancers, or what kind of cancers. 

If you're wondering what happens to the patients in a cancelled trial: in this case, they will continue to receive treatment. The trial (called SYMPHONY-1) involved 2 groups. One received R-Squared (Rituxan and Revlimid) + Tazemetostat, and the other received just R-Squared. So patients who were enrolled in the trial will all continue to receive R-Squared. They won't be left without treatment. 

I have mixed feelings about accelerated approvals. They make new treatments available to patients who might need them. But they also risky in that they haven't gone through the full process that other treatments have gone through. On the other hand, even if there had been a phase 3 trial, the patients who volunteered for it would still be dealing with the same risks. It's all very complicated.  

The unfortunate part for all of us is that we have one less treatment available to us. And for those with the EZH2 mutation, that's even more unfortunate.  

But we can stay hopeful. There are lots of treatments available to us, and many more potential treatments on the way.