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Leukaemia is a common form of cancer that affects millions of people worldwide. In 2013 alone, there were 414,000 new cases of leukaemia diagnosed globally and approximately 265,000 leukaemia deaths.

Researchers around the world have been creating innovative new treatments to combat this disease using genetically modified immune cells. These cells can hunt down and kill leukaemia cells within the body. This article will take a closer look at recent research findings to see if a new therapy to treat leukaemia is possible.

Understanding leukaemia

Leukaemia is a form of cancer that affects the blood-forming tissues within the body, including the bone marrow. There are four types of leukaemia:

Acute myeloid leukaemia (AML)

This is fast-growing form of cancer that affects the bone marrow and blood.  It causes the bone marrow to produce mostly immature white blood cells. These malformed cells are not capable of fighting off infections, causing the patient to be highly vulnerable to common conditions. AML is the most common form of leukaemia.

Chronic myeloid leukaemia (CML)

This form of myeloid leukaemia also causes the bone marrow to produce immature white blood cells. The key difference is that it is a slower moving form of leukaemia that is associated with an abnormal chromosome called Philadelphia chromosome (Ph chromosome).

Acute lymphocytic leukaemia (ALL)

This form of leukaemia causes many abnormal white blood cells (lymphocytes) to accumulate in the bone marrow. These malformed cells eventually outnumber the functional lymphocytes in the body and spread to other parts of the body.

Chronic lymphocytic leukaemia (CLL)

This is a slow growing cancer that begins in the lymphocytes inside the bone marrow and moves into the blood.

Umbilical cord blood stem cells are often used in conjunction with chemotherapy to treat leukaemia. A harsh chemotherapy treatment is used to stop or slow the production of cancer cells. After that treatment has concluded, the patient will receive a transfusion of stem cells to help their body produce healthy blood cells once more. It is a very effective treatment combination and umbilical cord blood stem cells are often used for this type of procedure.

New treatments using modified immune system cells

Cancer cells only manage to survive in the human body because the immune system cannot correctly identify and kill them. Researchers have developed therapies using genetically modified immune cells to help immune cells find cancer cells and eliminate them.

Swiss healthcare company Novartis has developed a therapy to treat leukaemia called chimeric antigen receptor T cell (CAR-T) therapy. This is an innovative therapy to treat leukaemia, using cells drawn from the patient’s own body.

The process begins with blood being taken from the patient. The T-Cells are drawn from the blood and genetically modified so they can hunt cancer cells and B-Cells expressing a specific antigen.

The science behind this therapy was first developed by the University of Pennsylvania.  Novartis became involved in 2012, helping to fund the project.

Lead researcher Dr. Carl June, from the Perelman School of Medicine at the University of Pennsylvania said of the therapy: “We now know that it is possible to treat patients in clinical trials across the world using this approach, and the results we have observed mark a potential new paradigm in the treatment of blood cancers that have not responded to standard therapies.”

This treatment has received priority review from the US Food and Drug Administration (FDA), which means that its evaluation is expedited and we may see it available in the near future.

The Novartis-sponsored ELIANA study (NCT02435849) has already demonstrated that this treatment has incredible potential. It was a large Phase II study that involved 25 medical centres in the USA, EU, Canada, and Australia. In this study, 82% of the people receiving the CAR-T treatment achieved complete remission. The only negative outcome associated with using the CAR-T treatment was the high incidence of cytokine release syndrome, a dangerous inflammatory condition.

Researchers from the University of Texas M.D. Anderson Cancer Center have just published a paper that uses a similar approach to combatting leukaemia. The key difference is that they are using genetically modified natural killer (NK) cells that are derived from umbilical cord blood.

The researchers modified the NK cells by equipping them with a protein called interleukin-15. This protein allows the NK cells to persist in the body for many months, giving them time to deal with the cancer cells.

During the trial, the researchers discovered that the NK cells were more efficient at finding and kill cancer than the CAR-T treatment. The best part about this therapy to treat leukaemia is that it also avoids cytokine release syndrome.

M.D. Anderson Cancer Centre is continuing to test NK cells for the treatment of chronic lymphocytic leukaemia (CLL), non-hodgkin lymphoma, and acute lympocytic leukaemia (ALL).

Sources

  • NCBI. (2017). The Global Burden of Cancer 2013. [online] Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4500822/ [Accessed 22 Sep. 2017].
  • Clinicaltrials.gov. (2017). Determine Efficacy and Safety of CTL019 in Pediatric Patients With Relapsed and Refractory B-cell ALL – Full Text View – ClinicalTrials.gov. [online] Available at: https://clinicaltrials.gov/ct2/show/NCT02435849 [Accessed 22 Sep. 2017].
  • EurekAlert!. (2017). Genetically enhanced, cord-blood derived immune cells strike B-cell cancers. [online] Available at: https://www.eurekalert.org/pub_releases/2017-07/uotm-gec071217.php [Accessed 22 Sep. 2017].

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