Exciting Advances in Treating Mantle Cell Lymphoma
As a hematologist-oncologist, I treat patients with cancers originating in the blood, like leukemias and lymphomas. Lymphomas begin in a type of white blood cell called a lymphocyte; these cells, when healthy, help your immune system fight infections and other invaders. Mantle cell lymphoma (MCL) is a rare type of non-Hodgkin lymphoma that begins in lymphocytes located in the “mantle zone,” which is the outer edge of a lymph node. Getting a diagnosis of MCL can be overwhelming, because although it’s generally a slow-growing cancer, it’s usually fairly advanced by the time it’s found. However, today we have more treatment options available than ever before. Until recently, there were few therapies out there, but to fill that gap, researchers made an effort to study MCL and provide patients with effective treatments that can make a big difference.
Next Steps After Diagnosis
Our first task when someone is diagnosed with mantle cell lymphoma is to determine how aggressive we expect it to be. For some, MCL doesn’t require immediate treatment because it hasn’t advanced to a threatening level. But in most cases, treatment is necessary as soon as possible. To assist in this decision, we use a scoring system called the Mantle Cell International Prognostic Index (MIPI) that considers the patient’s age, quality of life, speed of cancer progression, and other factors. This helps us understand the prognosis of that person, how well they might respond to chemotherapy and other treatments, and how likely it is that their disease could go into remission. We will look at the cancer cells under a microscope to see how quickly a patient’s MCL is growing, and then using that with the MIPI score, we choose the right treatment for each individual patient.
If your MCL is growing rapidly, we’ll go with more aggressive treatments. But if it’s moving more slowly, we may choose other drugs that, while still very effective, are a little less intensive.
Initial MCL Treatment
For most first-time patients, therapies haven’t changed that much. The most exciting advances in MCL treatment today are targeted towards people who relapse, although there are several clinical trials in the works looking at new treatments for initial therapy, and there are a few new effective therapies available. If you’re diagnosed with MCL for the first time, you’ll likely receive chemotherapy off the bat. Another option is also available for some people with more aggressive disease: a stem cell transplant. This can enhance the body’s response to chemo and prolong remission. We may also treat these patients with a type of drug called a proteasome inhibitor like bortezomib (Velcade); this medication can prevent lymphoma cells from growing and it can actually kill them completely. It can be used in patients with new MCL or in MCL that returns (relapses). It’s common for patients to do well on these treatments and many of my patients find their MCL goes into remission after a period of time.
Breakthrough Treatments When MCL Returns or Doesn’t Respond to Treatment
When MCL relapses, or initial therapies don’t work (known as refractory MCL), it can be a difficult and emotional realization. But I want patients to know that today we have more therapies than ever before to treat relapsed or refractory MCL. New drugs called BTK inhibitors, like ibrutinib (Imbruvica) and acalabrutinib (Calquence), are effective medications with mild side effects. They work to block an enzyme called the Bruton’s tyrosine kinase enzyme, which impairs the ability of lymphoma cells to talk to one another and tell each other to grow, which means tumors can shrink. They are often our first choice therapies when a patient’s MCL has come back. Although they don’t cure MCL, they do often allow for remission that can last for a fair amount of time. The side effects are generally tolerable, which is another benefit. In some cases, patients can’t tolerate these drugs, so we’ll turn to another treatment called lenalidomide (Revlimid), which helps your immune system attack lymphoma cells and prevent their growth.
There are currently trials studying the effects of a treatment called CAR T-cell therapy, and we are eagerly awaiting some of the longer-term data from these clinical trials. Previous studies look promising but we don’t yet know how long the effects can last. The good news is the response rate is positive and side effects are as expected and generally tolerable. The cancer center where I work has worked on some of these studies, so when patients are determined to be good candidates for this treatment, we’ll collect some of their T-cells, which are a type of immune system cell, and then ship those off to a company that modifies the cells by adding a receptor that helps them identify and kill cancer. These modified cells are called CAR T-cells, and they’re returned to us and then infused back into the patient’s body. Some of the results we see are amazing, and many of my patients that have received the therapy are alive and well today–and that may not have been the case without it. The Food and Drug Administration (FDA) recently approved a form of CAR T-cells, brexucabtagene autoleucel (Tecartus), for use in relapsed/refractory MCL, which is very exciting us all of us, including patients with MCL.
The bottom line is today we have many new options for treating mantle cell lymphoma that we didn’t have even a few years ago. This gives me and my patients hope, and I feel optimistic about the future as more treatments come down the pipeline to offer patients a chance at longer and fuller lives despite their MCL.