Selling Kite Pharma has elicited a lot of interest due to the amount of money being paid, but it is based on fascinating scientific developments with a solid Israeli base

Kite Pharma, which is the manufacturer of an Israeli-research-based immunotherapeutic treatment, has been sold to the large American pharmaceutical company Gilead for 11.9 billion dollars in cash. The treatment is based on genetic engineering of a certain type of immune cells, called T cells, in order to instill them with the ability to specifically kill cancer cells without harming other cells in the body.

Kite Pharma's chair, CEO and president is Prof. Arie Belldegrun, an Israeli doctor and scientist who has been residing in the USA since the 1980's. Belldegrun, an oncologist and urologist, studied medicine at the Hebrew University and continued his scientific and medical training at the Weizmann Institute of Science and Harvard University. He joined forces with an American researcher, Steven Rosenberg, in the attempt to enhance the activity of T cells, so that they are more effective in fighting cancer.

T cells are part of the adaptive immune system, which is the component of the immune system that learns to how to recognize foreign agents that pose a threat to the body and then, attack them. These cells play many roles, and among others, they are capable of destroying virus-infected cells and cancer cells. Belldegrun and Rosenberg found that it is possible to extract T cells from a patient, enhance their activity in the lab, let them replicate, and then inject them back into the patient. Since these are cells taken from the same person, the immune system will not attack them, which may happen when grafting cells from another donor.

Specific compatibility

The disadvantage of this method was that the enhancement of the T cells was not specific enough – namely, they were not effective enough in fighting cancer. This is where the method developed by Prof. Zelig Eshhar from the Weizmann Institute of Science came into play. T cells recognize the cells they are supposed to destroy via a receptor on their outer surface, which binds to a specific protein on the outer surface of the target cell.

Eshhar, in his pioneer research, developed a method for engineering the T cell receptor so that the region in it that is directed against the target cancer cell protein would be taken from a specific antibody. In this manner, he increased the specificity of the engineered cells, making them into effective machines that detect and destroy cancer cells. The technology was named Chimeric Antigen Receptor, or CAR (i.e., a chimeric receptor combining the original receptor and an antibody).

At this point, the researchers had the two components of a system capable of overcoming cancer: immune cells that were engineered to recognize cancer cells more effectively, so that they only attack them; and methods for culturing the engineered cells in the lab to large numbers, so that they can be injected back into the patients.

The therapeutic technique has been successfully tested in clinical trials on blood cancers, such as lymphoma and leukemia. This treatment is especially effective against these cancers since T cells reside naturally in the blood and lymph vessels, and the cancer cells are scattered there, as opposed to being lumped up in a solid tumor with hard-to-reach internal layers. Nowadays, trials are being carried out to test this treatment option in solid tumors.

המוחות שמאחורי ההצלחה. מימין: אשחר, רוזנברג ובלדגרין | צילומים: מכון ויצמן למדע, Kite Pharma, NCIThe minds behind the success. From the right: Eshhar, Rosenberg and Belldegrun | Photographs: Weizmann Institute of Science, Kite Pharma, NCI 

A good chance of approval

The leading product of Kite Pharma is called Axi-Cel, which is used to treat non-Hodgkin's lymphoma. The product still has not been approved by the FDA, which is in charge of approval of clinically tested drugs for marketing, but it is expected to gain approval in November this year. In light of this, it is even more impressive that the company was purchased, and indicates that Gilead, as well as the entire market, have a lot of faith in the therapuetic technique.

When Belldegrun, Rosenberg and Eshhar conducted these revolutionary experiments three decades ago, few believed the treatment would work. It sounded like science fiction. Evidently, it took many years to perfect the treatment and make it safe to use. This treatment is part of the immunotherapy revolution we have been witnessing in cancer treatment in recent years, which is gradually moving from the laboratories and clinical trials to routine treatment in the health system, promising new hope for millions of cancer patients around the world.

Watch Kite Pharma's video about the CAR treatment:

Translated by Elee Shimshoni

1 comment

  • Giuseppe

    Very good summary article

    Very good summary article about a real breakthrough...