Could cancer immunotherapy be the solution for the future?

by Soh Min Min
CAR-T cell therapy may be a promising cancer therapy of the future. Source

Just yesterday (18 Oct), the Food and Drug Administration (FDA) approved its second chimeric antigen receptor (CAR)-T cell therapy to treat cancer. A form of gene therapy, CAR-T cell therapy reprograms the body’s own white blood cells, specifically T cells, to recognise and kill cancer cells.

The new therapy, Yescarta, is approved for treating the more aggressive types of large B-cell lymphoma that have not responded to two or more types of treatment. In a clinical trial of over 100 patients, the complete remission rate after treatment with Yescarta was 51 percent.

“The approval of Yescarta brings this innovative class of CAR-T cell therapies to an additional group of cancer patients with few other options,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research (CBER).

“Today marks another milestone in the development of a whole new scientific paradigm for the treatment of serious diseases,” said FDA Commissioner Scott Gottlieb, M.D, in a statement released by the FDA, adding that the approval demonstrated “the continued momentum of this promising new area of medicine”.

Yescarta was developed by Kite Pharma (now Gilead Sciences). The treatment would cost $373,000. It is meant to be administered once, injected into the vein. The customised injection consists of engineered T cells manufactured from each patient.

David Chang, Kite’s chief scientific officer, says that new CAR-T treatments are under development for other cancers, such as multiple myeloma.

Immunotherapy has been a hot topic in recent years and research in this area has progressed tremendously from being a potential strategy to actual implementation in the clinical setting. The technique has been especially successful in treating lymphomas.

The first FDA-approved CAR-T immunotherapy, Kymriah. It is used to treat a common childhood cancer of the blood. Source

Earlier this year, FDA granted approval of the first CAR-T immunotherapy, Kymriah, to Novartis Pharma. In the clinical trial carried out to test Kymriah’s effectiveness, 83% of patients became cancer free within 3 months. Kymriah is administered to patients up to 25 years of age with a form of acute lymphoblastic leukemia (ALL), the most common childhood cancer in the U.S. The treatment costs $475,000.

Amidst its successes, CAR-T therapy has been associated with severe side effects in some patients. Treatment with CAR-T may result in cytokine release syndrome, which happens due to over-activation of the immune system. The treatment may also cause neurotoxicity. Both of these side effects can be life-threatening. Intensive monitoring, accurate diagnosis and prompt treatment would help to minimise problems associated with the therapy.

Apart from the high costs and serious side effects, it is clear that CAR-T therapy works. The dual approval by FDA opens up new treatment options for those who have run out of them. Future developments in the field of immunotherapy may open up new treatments for other types of cancers and increase the number of patients who end up cancer-free. Managing toxicity would also be a necessary step to advance this technique for treating various types of cancers in the future.