FDA panel recommends new breakthrough gene therapy for B-cell acute lymphoblastic leukemia (ALL)

A Food and Drug Administration (FDA) panel created history by recommending a gene therapy for patients with cancer. In this therapy the patient’s own genes would be modified to fight the cancer cells. The patient’s cells which are thus altered to treat the cancer would thus be termed as “living drugs” as they act as soldiers to treat the cancer. These cells boost up the immune system and help the body fight the cancer.

The recommendation, if adopted could be the first gene therapy that has left the laboratory and reached the market. This is a major achievement for Novartis that is the first pharmaceutical company to bring this therapy into the market. The treatment was developed by scientists at the University of Pennsylvania and is licensed to Novartis. The treatment is called CTL019 or tisagenlecleucel.

CTL019 treatment  is for a type of leukemia or cancer of the white blood cells of the blood. The treatment is being specialized for other forms of cancer as well. Multiple myeloma patients and those with an aggressive for of brain tumor may also benefit from this type of treatment.

For this therapy around a million of the patient T type of immune cells would be genetically engineered and altered. These would then kill the cancer cells. For this a disabled form of HIV virus is used. This disabled for the virus molecule cannot cause any disease but acts as a courier to carry the desired genetic material into the T cells in order to reprogram them. Now the T cells become equipped to attack the rogue B cells that have become cancerous. They can identify the B cells by a protein marker on their surface called CD-19. Once identified the B cells are killed by these special T cells.

For the therapy, some cells of the patient is first removed. These cells are to be removed at an approved medical centre before they can be frozen, packed and sent to a Novartis laboratory where they would be altered and processed after thawing. Then they are frozen for transit and shipped back to the treatment centre. These altered cells are now given to the patient. The treatment of a single injection with these altered cells has shown long term remission (freedom for the cancer for a period of time) and even cures (complete freedom from the cancer) in many patients who were part of the trial. The recommendation comes for patients of B-cell acute lymphoblastic leukemia (ALL) among patients aged 3 to 25 years who had not responded to earlier treatments or whose cancers have come back or relapsed after a period of remission.

One of the first cases of the success with this therapy is Emily Whitehead who is now 12 years of age. She received the treatment at the age of 6 years in 2012 at the Children’s Hospital of Philadelphia. She initially developed severe reactions to the treatment including high fever, lung congestion and very low blood pressure. She was critically ill for a while before she pulled through and finally came out to be cancer free for all these years.

The study that Novartis conducted and was sent up for approval of the therapy included 63 patients who received the treatment between April 2015 and August 2016. After treatment it was found that 52 of these 63 (82.5 percent) were deemed to be in remission. This is a very high rate of remission in a clinical trial that studies cancer patients. In the study 11 patients died despite the treatment. The patients who have been given the treatment are being tracked for 15 years before they are deemed cancer free.

Dr. Carl H. June, one of the lead researchers of this therapy said that these altered T cells could each kill up to 100,000 cancer cells. But the cells also kill health B cells and thus the side-effects are severe. Patients need to be protected from infections and they receive infusions of immune globulins that boost immunity.

Dr. Gwen Nichols, the chief medical officer of the Leukemia and Lymphoma Society called the new therapy “exciting”. The Leukemia and Lymphoma Society funded part of this research which finally came up with this treatment. She explained that in future studies would also focus on persons whose disease is less advanced and immune system is stronger. Together with this treatment the outcomes may be better.

The treatment would of course still be under intense scrutiny as it caused serious adverse effects, some of which could be fatal too. Further the effects of these infused altered cells within the body in the long term are unknown. These cells could in future themselves turn and cause secondary cancers. These are personalized treatments and could cost more than $300,000 according to speculations. However no confirmation on the price is in yet.

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