Panel Backs CAR T-cell Therapy for Leukemia: What You Need to Know and What’s Next

Written By:Elizabeth Mendes
Illustration by Sanithna Phansavanh

The US Food and Drug Administration (FDA) this week convened a panel of outside experts to weigh in on the readiness of a first-of-its-kind cancer therapy. The treatment, which works by tweaking a patient’s own cells, is a type of immunotherapy called CAR T-cell therapy and has been in clinical trials for several years. One drug maker is now seeking FDA approval to use the treatment in pediatric and young adult patients ages 3 to 25  with B-cell acute lymphoblastic leukemia (ALL) that has not responded to standard care. 

After the July 12 day-long meeting, the FDA panel unanimously recommended that the agency approve the treatment. But what does this mean for patients? And is CAR T-cell therapy going to play an increasing role in cancer treatment in general? In this interview, Leonard Lichtenfeld, MD, MACP, American Cancer Society deputy chief medical officer, gives us his take.   

What is the purpose of the FDA panel that met yesterday – what does their recommendation mean for this treatment and for patients?

Dr. Len: The FDA has responsibility for approving new treatments for cancer and for many other diseases. Sometimes during that approval and review process, they have specific questions that require outside expertise. It may be something as significant as whether a drug is effective or safe. In this situation, the FDA was more interested in the new way this CAR T-cell therapy would be manufactured and administered to patients, as well as what the long-term side effects might be – or how to handle the fact that we don’t know much about the long-term side effects or effectiveness. The panel doesn’t make a final decision; that is up to FDA staff, but the FDA does consider the panel’s input to be very important and useful.

Why is this generating so much news coverage if it isn’t even approved yet?

Dr. Len: It has become clear over the last several years that immunotherapy – treatments that use the body’s own internal defense mechanism to fight disease – has become an important part of cancer treatment. We have seen several new immunotherapy drugs become available that have effectively treated diseases that in some cases previously had no effective treatment. But this new treatment, if approved by the FDA, would be the first CAR T-cell therapy available outside of clinical trials. It is different from other types of immunotherapies that are already FDA approved.

CAR-T therapy reengineers patients’ own immune cells (specifically, white blood cells called lymphocytes) to attack cancer cells in the body. To do this, scientists take out some of a patient’s lymphocytes, genetically change them to attack the cancer, grow those new lymphocytes in a lab, and then give those cells back to the patient.

This type of treatment has shown success in several diseases where there have been patients, including some very young pediatric patients, who had received and failed all other known effective treatments. These are patients who had no hope left – no other treatments to try. They used these reengineered lymphocytes and saw very dramatic responses and improvements in those patients. And that has generated a considerable amount of interest and excitement.

What did we learn from yesterday’s meeting? Anything new?

Dr. Len: What we did learn was that the panel agreed that these treatments can be effective for appropriate patients. Importantly, we learned the panel is in agreement that this treatment should be made available for care of patients at this time – that we should not wait. The opinion of the panel is important in that they all agreed that we didn’t have to wait longer to get this treatment into care now even though we don’t have all the answers.

What do we still not know about this treatment? And what are the biggest concerns?

Dr. Len: We still don’t know exactly how long benefits may last and we don’t know the long-term side effects. The treatment just hasn’t been around long enough to find out. Inevitably, things will occur that we haven’t yet seen. That is why it is so important that patients be followed up long-term.

It is important to note that some patients had good responses, but the response only lasted a very short time. Some of these patients have gone on to die. And the treatment itself can be life threatening. People shouldn’t have the impression that this will be a treatment for every patient. It is only for a very small fraction of patients. In addition, even if approved, it won’t be generally available at every doctor’s office or hospital in the country. The plan at this point is that it will be limited to few treatment centers in the country and only small numbers of people are eligible for it at this time.

It is also a difficult treatment to make. This is a complex process with multiple steps that require very strict attention to details: How the cells are taken out, handled, shipped, manufactured, grown, and ultimately put back into the patient. If each step is not done in absolutely the best way possible, there could be a serious problem.

If the FDA approves this treatment, which they are expected to do later this year, who can benefit from it?

Dr. Len: The potential forthcoming approval of the treatment would only be for certain patients with certain types of leukemias and lymphomas who have failed other effective treatments. The reality is that we have effective treatments for most of these cancers already and this is for people including children who fail all of the treatments that are known to work. So it is a very small group. While many in this group have benefitted from the clinical trials, an FDA approval would increase availability and capacity for this treatment. An approval would increase access and get the treatment to more patients.

But it is going to be very expensive and not easy for everyone to access. We must be sensitive and aware of that. There need to be supports in place so that everyone who needs this treatment is able to get it.

The drug company Novartis is seeking approval for use of the treatment for a specific and small set of patients. But the company – and other drug makers as well – hope that this type of treatment will be useful in many other types of cancer and groups of patients, right? How hopeful are you?

Dr. Len: I have been concerned about hope and hype in cancer care for decades – the challenge of overpromising and underdelivering. But over the past 7 or 8 years, I have been really surprised about how effective some of these immunotherapy treatments have been, especially in situations where previously we have had nothing meaningful to offer to patients. These CAR T-cell treatments are another step forward in offering people facing terminal illness a real possibility.

Clinical trials will continue because there is still more to learn. Researchers are working to improve this treatment and study it in more tumor types including in solid tumors.  

Video: Learn More About Car T-cell Therapy

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

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