Transcript
My name is Elizabeth Brem. I'm an Assistant Clinical Professor at UC Irvine. One of the talks I gave this morning was about systemic marginal zone lymphoma.
We started by just reminding everyone that there are actually 3 kinds or 3 flavors of marginal zone lymphoma. They present a little bit differently. There are slightly different considerations for each one of them.
The one that's the most common is the mucosa-associated, or MALT lymphomas. Most commonly, this is gastric, but you can also see ocular marginal zone lymphomas as well as cutaneous marginal zone lymphomas.
The second is the splenic marginal zone lymphoma. As you might imagine, these patients typically present with splenomegaly, but they can also have bone marrow involvement and present with cytopenias. Sometimes, they can actually present with a leukocytosis.
Then you have the nodal marginal zone lymphomas who, as the name implies, present with enlarged lymph nodes.
Why is it important to differentiate these? If you do have a gastric, for example, marginal zone lymphoma, a proportion of those will be associated with H. pylori infection. In some of those patients, you can get away with actually just treating the H. pylori. Treatment of the H. pylori will actually treat the marginal zone lymphoma.
In situations where the H. pylori is negative, you go a different route. You think about radiation, depending on the size and the location of the disease, or perhaps single-agent rituximab.
For the cutaneous marginal zone lymphoma, particularly in Europe, there's some data that Borrelia infection can be associated with this. Seems to be less of an epidemiologic link in the US, but something to think about.
Staying on the topic of infections, we know that splenic marginal zone lymphoma can be associated with hepatitis C. Always screen those patients for hep C because there are some patients who with eradication of the hep C will also eradicate their marginal zone lymphoma.
In the cases of these patients who need therapy, who do not have, for example, an infection that can be treated like I mentioned, there's a number of options out there.
In many ways, they can be relatively similar to follicular lymphoma, particularly because a lot of the studies they take all comers of indolent lymphomas. They end up being majority follicular with a handful of marginal zone patients.
We looked again at the GADOLIN study, which looked at bendamustine-obinutuzumab. This might be something you want to think about in the relapsed-refractory setting. Again, not a ton of these patients had marginal zone lymphoma. Most of them had follicular.
In general, when you look at that study as a whole, the bendamustine-obinutuzumab had a better progression-free survival compared to bendamustine alone.
We talked a little bit about the data for lenalidomide in marginal zone lymphoma in the upfront setting. This is not approved, but in the relapsed/refractory setting, it is. If you look at the AUGMENT study, you can see that adding lenalidomide to rituximab versus rituximab plus placebo, it improved progression-free survival.
The other tool you have that's for marginal zone that's relatively unique to marginal zone is ibrutinib. While ibrutinib has been an excellent drug in CLL, it's been a good drug in Waldenström's, it's not a great drug in follicular lymphoma. However, it does work pretty darn well in marginal zone lymphoma.
A lot of times, I think sometimes people feel like a low-grade lymphoma is a low-grade lymphoma. This is one situation where you may want to take the time to talk to your pathologist, make sure you really know the diagnosis, because if this is marginal zone and not follicular, you can often tell that by looking at CD10.
Follicular is usually CD10-positive while marginal zone is CD10-negative. That's an extra tool in your kit where you can think about using ibrutinib.
The other class of drugs that we talked about were the PI3 kinase inhibitors. Again, a similar story where the studies took all comers of relapsed/refractory indolent lymphomas. Only a handful of patients had marginal zone lymphoma, but we did look at the waterfall plots for each of the drugs that are FDA-approved, duvelisib, idelalisib, and copanlisib.
It does seem like the majority of patients with a marginal zone lymphoma did have a response in these studies.
Then you're stuck deciding which drug you want to use. You were going to probably choose that based on preference in terms of route of therapy. Idelalisib and duvelisib are PO versus copanlisib, which is IV. Each has a different set of toxicities as well.
