FDA approves first gene-altering leukemia treatment

The US Food and Drug Administration (USFDA) on 30 August 2017 approved a new leukemia treatment, called Kymriah.

The agency considers the treatment as the first gene therapy that it has cleared to hit the market in the United States.

The treatment aims to give some patients a second chance after first-line drugs have failed. Each dose of Kymriah contains a patient's own immune cells, which are sent to a lab to be genetically modified using a virus. This therapy, known as chimeric antigen receptor T-cell therapy (CAR-T), gives the cells the ability to recognize and kill the source of the cancer.

About Kymriah

• Kymriah is a cell-based gene therapy.

• It is approved in the US for the treatment of patients up to 25 years of age with B-cell precursor Acute Lymphoblastic Leukaemia (ALL) that is refractory or in second or later relapse.

• The therapy is a genetically-modified autologous T-cell immunotherapy.

• Each dose of Kymriah is a customized treatment created using an individual patient’s own T-cells, a type of white blood cell known as a lymphocyte.

• The patient’s T-cells are collected and sent to a manufacturing centre where they are genetically modified to include a new gene that contains a specific protein that directs the T-cells to target and kill leukaemia cells that have a specific antigen (CD19) on the surface.

• Once the cells are modified, they are infused back into the patient to kill the cancer cells.

• The safety and efficacy of Kymriah were demonstrated in one multicenter clinical trial of 63 pediatric and young adult patients with relapsed or refractory B-cell precursor ALL. The overall remission rate within three months of treatment was 83 percent.

• However, treatment with Kymriah has the potential to cause severe side effects. It carries a boxed warning for cytokine release syndrome (CRS), which is a systemic response to the activation and proliferation of CAR T-cells causing high fever and flu-like symptoms, and for neurological events. Both CRS and neurological events can be life-threatening.

• Because of the risk of CRS and neurological events, Kymriah is being approved with a risk evaluation and mitigation strategy (REMS), which includes elements to assure safe use (ETASU).

What is acute lymphoblastic leukaemia?

• The acute lymphoblastic leukaemia is a cancer of the bone marrow and blood, in which the body makes abnormal lymphocytes.

• The disease progresses quickly and is the most common childhood cancer in the U.S.

• The National Cancer Institute estimates that approximately 3,100 patients aged 20 and younger are diagnosed with ALL each year.

• ALL can be of either T- or B-cell origin, with B-cell the most common.

• Kymriah is approved for use in pediatric and young adult patients with B-cell ALL and is intended for patients whose cancer has not responded to or has returned after initial treatment.