Will a second infusion of CAR T cells help against cancer?

Sep 19, 2022
Devin Golden

Will a second infusion of CAR T cells help against cancer?

One of the benefits of CAR T-cell therapy is that many patients only need one infusion of engineered T cells to begin sending cancer into remission. The infused CAR T cells multiply in the body and turn into a “living therapy” that can persist for years.

Scientists are wondering whether some patients may benefit from a second infusion of CAR T cells to help the immune system keep the cancer in retreat.

Memorial Sloan Kettering Cancer Center in New York is hosting a phase 2 clinical trial examining this theory.

The study will administer a second infusion of the CAR T-cell therapy Kymriah® (tisagenlecleucel) for children and young adults with acute lymphoblastic leukemia.

CAR T-cell therapy is a type of cell and gene therapy changing how blood cancers are treated for many patients. Doctors remove T cells from a patient and send them to a laboratory, where scientists create a special protein receptor (called a chimeric antigen receptor). This new protein receptor is added to the T cells to direct their focus to cancer cells expressing the associated protein.

Once the T cells are turned into CAR T cells – and after they’ve multiplied to increase the potency – they’re infused back into the patient’s bloodstream.

History of CAR T-cell therapy for leukemia

The U.S. Food and Drug Administration (FDA) approved Kymriah more than five years ago for acute lymphoblastic leukemia (ALL) in people up to age 25. It was the first CAR T-cell therapy ever approved.

Leukemia is a fast-growing blood cancer in which B cells (blood cells) mutate, replicate, and grow uncontrollably. This leads to having too many B cells in bone marrow and the blood. Kymriah is a CAR T-cell with a protein receptor specifically for a protein found on B cells.

The FDA approval of Kymriah came after years of research and a successful clinical trial that gave widespread credibility to cancer cell and gene therapy. Carl June, MD, (University of Pennsylvania) is credited with developing this CAR T-cell therapy for ALL. The research and development by Dr. June was funded by Alliance for Cancer Gene Therapy, as one of ACGT’s first Research Fellows.

Dr. June is now a member of the ACGT Scientific Advisory Council along with 15 other thought leaders in the field of cell and gene therapy. Your donation to Alliance for Cancer Gene Therapy empowers our organization and the Scientific Advisory Council to fund other research programs that may lead to similar breakthroughs in cancer treatment.

Since the approval of Kymriah, there have been five additional CAR T-cell therapies approved for other blood cancers, such as lymphoma.

CAR T cells are made through a multi-step process that usually spans a few weeks.

Details of the new CAR T-cell study

Doctors at Memorial Sloan Kettering Cancer Center will administer a second infusion of Kymriah 1-2 months after the first infusion. The goal is to achieve an effect of CAR T-cell therapy called “B-cell aplasia” for longer.

B-cell aplasia is when there is a low number of B cells in the bloodstream. Kymriah has a protein receptor directing it to attack all B cells – cancerous and healthy – with a specific protein receptor.

The study is for people ages 25 and younger, imitating the FDA’s approval in 2017. Other patient eligibility criteria includes:

  • Enough CAR T cells for a second infusion
  • Patients in B-cell aplasia and their acute lymphoblastic leukemia in remission
  • Recovered from serious side effects caused by the first infusion

For more information on this clinical trial, visit the Memorial Sloan Kettering Cancer Center website.