The field of cancer immunotherapy has been booming at an alarming rate in recent years, and investors have invested tens of billions of dollars in this field. By enhancing human beings’ immunity to treat tumors, immunotherapy has brought new hope to cancer treatment.

With the success of the first immunoassay suppression point, many people are beginning to focus on CAR-T technology, which is becoming an explosive market for the next cancer treatment. The treatments developed by Kate Pharmaceuticals owned by Novartis and Gilead were first approved by FDA, and there are hundreds of clinical trials ongoing around the world.

But we can't help but ask: Is CAR-T really able to cure all cancers? Is this technology really worthy of people's expectations? The treatment process is accompanied by serious side effects, and there are still death cases reported in some clinical trials. Is this technology really ready? Is the expensive treatment cost really worth paying? In the future, what expectations should we have for this technology?

The magic of CAR-T technology

CAR-T is both a cell therapy and a gene therapy and immunotherapy. It is a new technology that completely deviates from drug therapy. T cells are a type of immune cells often perceived as soldiers of the immune system. When the body's immune system is attacked, these soldiers will be deployed to destroy those invading viruses, pathogens, and cancerous cells.

But in addition to the invading pathogenic microorganisms and the diseased cells, there are many normal cells in the human body. In the process of functioning, how do immune cells distinguish between "good cells" and "bad cells"? There are many antigens on the cell surface. These antigens are like the "ciphers" between cells and cells. It is through these "ciphers" that T cells distinguish between those of their own and those who are invaders. However, tumor cells are very foxy. They have many ways to confuse T cells and let T cells think they are their own, thus escaping from the recognition and attack of T cells. Without the restraint of T cells, these tumor cells will proliferate indefinitely in the human body.

CAR-T cells are actually a combination of T cells and CAR (chimeric antigen receptor) cells. CAR cells are the core components of CAR-T cells that confer T cell the ability to recognize tumor antigens. With the help of CAR cells, the T cell army will be even more powerful. New cells are able to recognize specific antibodies from tumor cells. At the same time, when bound to tumor cells, T cells inside the CAR-T cells will be activated to target the tumor cells.

The second and third generation CAR-T cells also have additional stimulation zones that are more effective in enhancing the immune response. Typically, the first step in CAR-T cell therapy is the extraction of patient’s T cells, a step known as leukocyte depletion. These T cells will be genetically engineered in vitro and modified on CAR cells for amplification in vitro. Finally, these engineered cells will be reintroduced back into the body, ready to fight against tumor cells.

Prospects of CAR-T in cancer therapy

Immunologically based checkpoint inhibitors have been successful in tumor therapy. They enhance the killing effect of T cells on tumor cells by inhibiting the escape mechanism of tumors.
The cell-based immunotherapy- CAR-T therapy further enhances the killing effect of T cells on tumor cells by improving the ability of the immune system to capture tumor antigens.

CAR-T therapy showed a very positive prospect in clinical trials and showed an effect on 94% of severe tumors. This is very surprising, as most of the patients enrolled in the CAR-T clinical trial did not respond after using other therapies. In terms of efficacy, the performance of CAR-T exceeded the expectations of patients and investors. But everything has two sides, CAR-T also has shortcomings such as serious side effects in the fight against tumors, including neurotoxicity and cytokine release syndrome. In 2016, several companies reported several deaths in the later stages of CAR-T treatment. This made us realize that this technology may not be as perfect as we imagined.

How to optimize CAR-T treatment

Although some people are arguing the risk of CAR-T therapy, the good news is that they can be improved to make the treatment safer.

Cellectis, a French company whose CAR-T therapy is called ucart19, has signed a licensing agreement with Sevier and Pfizer. Cellectis licenses a switch control system that allows T cells to be activated only when the patient is injected with rapamycin. In a humanitarian situation, the company successfully saved the lives of two children with aggressive leukemia, and the treatment also entered the clinical phase I. Bellicum Pharmaceuticals, a US company that is developing a similar technology called GO CAR-T, requires a drug called rimiducid to activate CAR-T cells. More efforts are still needed.

Author's Bio: 

Creative Peptides is actively involved with novel drug research efforts. In addition to offering various MHC peptides, cosmetic peptides, it also provides custom conjugation services such as bioconjugation and Silver Nanoparticles Conjugation to facilitate scientist’s endeavors.