Expert panelists review the pathophysiology of marginal zone lymphoma and reflect on its prevalence as a rare disease.
Bhavesh Shah, RPh, BCOP: Hello, and welcome to this Pharmacy Times® Insights program. Today we’re going to be talking about treatment innovations in relapsed/refractory marginal zone lymphoma. My name is Bhavesh Shah, and I’m the associate chief pharmacy officer for hematology-oncology and specialty pharmacy at Boston Medical Center. Joining me in this discussion are my colleagues Dr Amitkumar Mehta, who is an associate professor for the division of hematology-oncology at the University of Alabama [at Birmingham Comprehensive Cancer Center], and Dr Javier Munoz, the program director for lymphoma at the Mayo Clinic in Phoenix, Arizona.
Today we’re going to be talking about several topics pertaining to the treatment of marginal zone lymphoma in the relapsed/refractory setting. We’ll discuss the unmet needs regarding treatments, the potential use of BTK inhibitors, and the critical role a pharmacist plays in the treatment of these patients. Let’s get started. First, Amit, do you want to take the lead on describing the pathophysiology in marginal zone lymphoma, the different subtypes, and what we’re going to be focusing on, specifically the type of marginal zone lymphoma?
Amitkumar Mehta, MD: Thank you, Bhavesh. Hi, everyone. We’re going to talk about marginal zone lymphoma. Marginal zone lymphoma is a type of B-cell non-Hodgkin lymphoma. It’s considered a low-grade lymphoma. As the name suggests, it arises from a marginal zone of either the lymph node, spleen, or mucosa-associated lymphoid tissue, or what we call MALT. Based on that, we have 3 subtypes. There’s nodal, which means they arise from lymph node. There’s extranodal, which means they’re not from the lymph node or other lymphoid tissue; the most common being stomach, which we call gastric MALT. It can be also adnexa of the orbit or other glands or lungs. The third variant is splenic marginal zone lymphoma.
Overall, marginal zone lymphomas are relatively rare. They make up about 10% of non-Hodgkin lymphoma. Within that, nodal marginal zone lymphoma is rare. About 4000 cases of nodal marginal zone lymphoma happen every year. The main pathophysiology of marginal zone lymphoma is chronic antigen stimulation, which can happen for a variety of reasons. I was mentioning stomach. External marginal zone lymphoma is 1 of the common variants where chronic antigen stimulation by Helicobacter pylori, H pylori gastritis, is 1 of the classic examples. The other important part I want to emphasize is hepatitis C. About one-quarter to one-third of cases of marginal zone lymphoma are associated with hepatitis C infection. That’s 1 of the things we’d definitely test in all the patients, apart from other regular tests for lymphomas.
Bhavesh Shah, RPh, BCOP: I’d anticipate that we’d be doing a full hepatitis panel because they might be starting B-cell therapy. That’s great insight. I didn’t know that hepatitis C was that prominent in this patient population. How does marginal zone lymphoma compare with other B-cell disorders? Are the characteristics or behaviors the same?
Javier Munoz, MD, MBA: It’s not 1 disease but many. Marginal zone lymphoma represents a group of lymphomas that have historically been classified together but are truly different. As Dr Mehta was discussing, there’s novel marginal zone lymphoma, splenic marginal zone lymphoma, and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, also known as MALT. Some of these external lymphomas grow from epithelial cells in the stomach or in the periocular area, hence they can remain localized in this area for a long time.
Because the clinical manifestations can be so powerful, we’re cautious not to give a blank check statement for treatment recommendations. Treatment needs to be individualized. Patients with localized disease could potentially receive localized treatment, like radiation. I was honored to participate in the ZUMA-5 trial of CAR [chimeric antigen receptor] T cells for indolent lymphomas. This is just to show that even though they’re grouped together, they’re quite different. Patients with marginal zone lymphoma didn’t respond as well as patients with follicular lymphoma. To sum it up, 1 size does not fit all when it comes to marginal zone.
Bhavesh Shah, RPh, BCOP: It’s great for the audience to know that. They don’t behave the same, even though it’s in the B-cell lymphoma category.
Transcript edited for clarity.