Multiple Myeloma

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Cytokine Release Syndrome: A CAR T-Cell Therapy Side Effect

Dr. Nina Shah UCSF Medical Center

Treatment for CRS

  • CRS is usually mild or moderate, and can be controlled with drugs.
  • The drug most commonly used is tocilizumab.
  • Being treated with tocilizumab should not change the outcome of your CAR T-cell therapy.

CAR T-cell therapy, a new immumotherapy treatment, is showing great promise for treating multiple myeloma and other blood cancers. In CAR T-cell therapy, a patients’ immune T-cells are removed from the bloodstream and sent to a lab to become more efficient cancer killers. The altered cells are then returned to the body where they can travel through the bloodstream to destroy cancer cells.

But like most powerful treatments, CAR T-cell therapy comes with the risk of certain side effects. One of the most common side effects, which can be serious, is called CRS, or cytokine release syndrome. “We like to explain this as a sort of flu, like an illness that you have after you get the T-cells,” explains Dr. Nina Shah, hematologist and professor of clinical medicine at the University of California San Francisco.

CRS occurs when the CAR T-cell therapy causes a large, rapid release of cytokines—small proteins that are part of the immune system—into the circulation. That release can cause a variety of reactions.

The Symptoms of CRS

The flu-like symptoms of CRS can include headache, fever, chills, scratchy throat, nausea, vomiting, diarrhea, muscle or joint pain and lack of energy. In addition, CRS can sometimes cause shortness of breath, low blood pressure and fast heart rate. Most people who develop CRS will have mild to moderate symptoms, but sometimes CRS can be serious and even life-threatening. Some patients will require hospitalization.

Fortunately, doctors are able to control this side effect. “We used to really worry about it a lot, but now we know that it can be controlled with a drug called tocilizumab (common brand name Actemra), which starts to bring down the reaction,” explains Dr. Shah. “And we know that receiving this drug tocilizumab probably doesn’t change the outcome of your CAR T-cell therapy.”

Because this side effect is fairly common, patients undergoing CAR T-cell therapy are understandably concerned that they might develop CRS. “But you shouldn’t worry about it, because not everybody gets it. And even if people get it, it tends to be what we call low grade, or not too dangerous,” says Dr. Shah.

Other Possible Car T-Cell Therapy Side Effects

CRS isn’t the only side effect associated with CAR T-cell therapy. Patients may have neurologic events that can include brain injury or malfunction, confusion, aphasia (difficulty understanding or speaking), drowsiness, agitation, seizures, loss of balance and altered consciousness. The treatment can also lower white or red blood cell count. Most of these side effects will resolve on their own or can be managed with medication. But patients should always let their physician or care team know immediately if they are experiencing side effects of treatment.

Dr. Shah says that during the pandemic patients are especially concerned about different treatment options, multiple therapies, and potential side effects. They want to know what the safest thing they can get is. “But it’s hard to know exactly the right answer to this, because things change every day,” says Dr. Shah. “What I tell my patients is that the multiple myeloma is unfortunately a definite, and Covid is a possibility. So we should definitely treat the myeloma and prevent the possibility of Covid by doing the best we can, which includes getting vaccinated and having our loved ones get vaccinated.”

The Covid safety recommendations for people with multiple myeloma are the same as for everyone else. “Make sure we all wear masks, follow all the rules, and understand that every step is a step towards prevention,” says Dr. Shah, adding that doing what’s necessary to prevent Covid ultimately allows each patient to get the best and most aggressive cancer care that they can. And when that treatment includes CAR T-cell therapy, it’s reassuring to know that while side effects may occur, they can be managed.

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Dr. Nina Shah is a hematologist who specializes in the treatment of multiple myeloma, a type of cancer affecting the blood marrow. She treats patients at the Hematology and Blood and Marrow Transplant Clinic. Read More