While the past decade has led to incredible advances in cancer treatment, much is left to desire for patients who do not respond to traditional treatment. For most patients with pediatric acute lymphoblastic leukemia (ALL), the outlook is relatively good. The five year survival rate for the average child affected with the disease is about 80% with little to no chance of remission after that time. For patients who do not respond to reatments currently on the market, there is a much lower chance of survival. This is estimated to be between 10 and 30 percent. The number of non-responsive patients includes an average of 620 children and young adults under the age of 25 each year.
About a quarter of all childhood cancer diagnoses are ALL, making it the most common diagnosis for those under the age of 14. ALL is a cancer that affects white blood cells, also known as lympohocytes. Premature lymphocytes later mature into either B or T cells which have specialized jobs. The B cells mature to create antibodies that attach to pathogens to help destroy them. The T cells come in different specialized types, but all help the body to fight off foreign invaders.
For patients with hard to treat cancers such as reoccurring ALL, there is hope for better individualized treatment. Multiple pharmaceutical companies have been working on trials for chimeric antigen receptor (CAR) T-cell therapies to treat at-risk patients. This therapy works by removing T-cells from the body and genetically engineering them. T-cells are cytotoxic and can directly kill other cells which they recognize as hazardous. After the T-cells are engineered, they produce chimeric antigen receptors on their surface. These receptors allow the T-cells to recognize the cancerous cells and kill them when reintroduced into the body.
So far, the use of CAR T-Cell therapies has been experimental and in trial stages. The Food and Drug Administration (FDA) has not approved any of these therapies for the general public yet. However, in July of 2017, Novartis brought its CTL019 treatment to an advisory committee meeting. This treatment is a CAR-T therapy for ALL The committee there voted 10-0 to approve the drug. While the FDA does not have to follow the recommendations of the advisory committee when it makes the final decision on whether to approve a treatment, it generally will make the same decision.
The FDA has not approved this treatment yet as there are still concerns to address. The trial was much shorter than expected since the preliminary results showed the treatment to be very effective. This means that serious side effects could be present which have not shown themselves in the short trial period. There was also concern about the side effects that were noticeable during the trial. Some patients ran high fevers or had nerve damage. CAR-T treatments have also lead to deaths from cerebral edemas in the past.
Although there are major concerns about the treatment and how it will be studied once it is on the market, it holds a lot of promise for treatments in the future. For children facing the unimaginable, CAR-T treatments could potentially make all the difference.
Read about ALL here
Read Novartis’s briefing submitted to the FDA here
Read about the advisory committee meeting here
Editor: Maria ‘Stefi’ Ticsa