CAR T-cell therapy is a type of immunotherapy used to treat multiple myeloma when other therapies have failed. It has improved remission and survival times, but long-term data on safety and success is limited.

Chimeric antigen receptor (CAR) T-cell therapy is a cell-based gene therapy. It’s also a form of immunotherapy because it helps the immune system find and attack cancer cells.

CAR T-cell therapy is used to treat blood cancers, including multiple myeloma.

This article discusses CAR T-cell therapy for multiple myeloma, how it works, and what you can expect during treatment.

T cells are a type of white blood cell that develop from stem cells in bone marrow. As part of the immune system, T cells help destroy abnormal cells and pathogens. In multiple myeloma, the T cells don’t recognize cancer cells as harmful.

The goal of CAR T-cell therapy is to correct that error.

In autologous CAR T-cell therapy, the treatment uses your own T cells. It starts with an intravenous (IV) blood draw. The blood runs through a machine that removes T cells, then returns the blood to you. This process, called leukapheresis, generally takes a few hours.

In a laboratory, the T cells undergo genetic engineering to introduce CARs on the surface of the cells. CARs are proteins that help T cells see targeted tumor cells. Once that’s done, scientists grow more cells in the lab. This can take several weeks. In some cases, you may have to repeat this process.

When there are enough CAR T-cells for the procedure, they’re frozen and sent to your treatment center. Then they’re thawed and infused back into your body. The new cells, which can now recognize and attack cancer cells, continue to multiply.

The two CAR T-cell therapies approved for multiple myeloma are idecabtagene vicleucel (Abecma) and ciltacabtagene autoleucel (Carvytki).

Multiple myeloma can become resistant to drugs that were previously working, so the disease often progresses. CAR T-cell therapy is most likely to benefit those whose myeloma has recurred or has stopped responding to other treatments.

It’s not a first-line treatment for myeloma. It may be a treatment of last resort, but it has improved remission and survival times. As with other treatments, the cancer can return even if CAR T-cell therapy works for a while. And some side effects are very serious.

An oncologist can review the benefits and risks so you can decide if it’s a good choice for you.

A few days before, you’ll likely get a short course of chemotherapy. This helps lower white blood cell numbers, preparing the immune system for the CAR T-cells.

In some cases, you can get CAR T-cell therapy as an outpatient, but it’s usually an inpatient procedure.

The medical team will infuse the CAR T-cells into your body through an IV line. This usually takes less than an hour although it can be as quick as 15 minutes. You’ll be watched closely during the infusion for any possible reactions. You may need to stay in the hospital for several weeks. With an outpatient procedure, you’ll need to have a caregiver on hand in case there are side effects.

The early or “acute” recovery phase lasts about 30 days. During this time, you’ll need to remain close to your hospital or infusion center in case complications arise. Longer term recovery varies, but you’ll need close monitoring for up to a year. In most cases, it’s a one-time treatment.

Potential side effects of CAR T-cell therapy include:

  • allergic reaction during infusion
  • weakened immune system
  • risk of infection
  • low blood cell counts

As CAR T-cells boost the immune system, it can lead to something called cytokine release syndrome. This usually occurs within a few days to a few weeks. Symptoms may include:

  • fever, chills
  • breathing difficulties
  • nausea, vomiting, diarrhea
  • dizziness, lightheadedness
  • headache
  • rapid heart rate

The treatment can also affect the nervous system, causing side effects such as:

  • headache
  • confusion, agitation
  • shaking, twitching
  • seizures
  • trouble speaking and understanding
  • loss of balance
  • changes in consciousness

Research suggests that CAR T-cell therapies are safe and effective for most people with recurrent or refractory multiple myeloma.

In a 2021 study, 73% of participants responded to treatment with Abecma, and 33% had a complete response, meaning there were no more signs of cancer. The median progression-free survival was 8.8 months overall.

In another small 2021 study, 97.9% of participants responded to Carvytki, and 80.4% achieved a complete response. The median duration of response was 21.8 months.

CAR T-cell therapy for multiple myeloma gained approval in 2017, so it’s still in its infancy. Data on efficacy and long-term safety are limited due to the short time frame and small numbers of trial participants. Researchers continue to follow those who have completed therapy in ongoing clinical trials.

The approach to treatment depends on factors such as:

  • extent and characteristics of disease
  • age and overall health
  • previous treatments

Treatment options for multiple myeloma include:

  • Chemotherapy: drugs that destroy fast-growing cells
  • Targeted therapy: drugs that target specific characteristics of the cancer
  • Stem cell (bone marrow) transplant: infusion with healthy stem cells after unhealthy ones are destroyed by high dose chemotherapy
  • Radiation therapy: to shrink myeloma cells in a specific area
  • Corticosteroids: to help fight myeloma cells and decrease inflammation

A doctor may offer supportive care for symptom management, and you may qualify to participate in a clinical trial.

CAR T-cell therapy is an option when multiple myeloma becomes resistant to other treatments. It involves altering your own T cells so they can recognize and attack cancer cells.

Still fairly new, CAR T-cell therapy is improving remission and survival times for people with multiple myeloma who have tried other therapies. But there are potentially serious side effects, and researchers are still waiting on longer term data.

CAR T-cell therapy isn’t for everyone, and everyone responds differently. An oncologist can review the potential benefits and risks of CAR T-cell therapy for you.