In a step that heralds a new era in cancer treatment, the US Food and Drug Administration (FDA) said it had approved a form of gene therapy that is highly effective at fighting an aggressive form of leukaemia in young patients with no other options.
SEPTEMBER 30, 2017
An illustration of the body's T cells attacking a cancer cell. — 123rf.com
The treatment, to be marketed under the name Kymriah, is neither a pill nor an injection, but a personalised medicine service that functions as a “living drug”.
Patients would have their body’s own disease-fighting T cells fortified and multiplied in a lab, then get the cells back to help them fight their cancer.
In clinical trials of 88 patients with a relapsing or treatment-resistant form of acute lymphoblastic leukaemia, 73 went into remission after receiving the experimental treatment.
FDA Commissioner Scott Gottlieb, himself a survivor of blood cancer, predicted that this new approach to cancer treatment would “change the face of modern medicine”.
Cancer researchers and physicians outside the agency shared Gottlieb’s enthusiasm.
Dr Crystal L. Mackall, associate director of Stanford University’s Cancer Institute, called it “a transformative therapy… It represents an entirely new class of cancer therapies that holds promise for all cancer patients.”
Acute lymphoblastic leukaemia is the most common form of paediatric cancer, affecting some 3,000 children and young adults yearly in the United States.
Though it is considered highly curable in most patients, about 600 each year either do not respond to chemotherapy or see their leukaemia return after an initial round of successful treatment.
“Those patients don’t make it – none of them do,” said Dr Stephan A. Grupp, director of the cancer immunotherapy programme at Children’s Hospital of Philadelphia, who administered the first course of Kymriah five years ago when it was an experimental treatment called CTL019.
Emily, shown here in 2014, was the first paediatric patient to receive the CAR-T therapy. Now 12, she was among those calling on the FDA to approve the treatment for other patients like her. — TNS
That initial patient, seven-year-old Emily Whitehead of Philipsburg, Pennsylvania, saw her leukaemia remit completely within three weeks of getting the treatment.
Now 12, she was among those calling on the FDA to approve Kymriah for other patients like her.
“Certainly for blood cancers, this is a game-changer,” Grupp said. Adapting this therapy for patients with solid tumors, he said, will be “the work of the next five years”.
The new approach was designed to fight some of the most stubborn cancers by giving the body’s immune system a very specific assist.
It starts by harvesting a cancer patient’s T cells, the warriors of the immune system.
The cells are delivered to a specialised lab where scientists alter their DNA, essentially reprogramming them to target cancer cells.
These re-engineered cells are called chimeric antigen receptor T cells, or CAR-T cells.
The new and improved cells are copied millions of times before they’re sent back to the patient.
Once infused into the bloodstream, the CAR-T cells are much better equipped to hunt down and kill cancer cells, wherever they may hide.
Novartis, the Swiss pharmaceutical company that developed the drug, intends to have 32 certified treatment centres up and running by the end of 2018. Patients up to the age of 25 would go to one of these centres to have their T cells harvested and later reintroduced in their modified form.
The cells themselves will be genetically engineered at a manufacturing facility.
Kymriah is the first CAR-T treatment to come before the FDA, but it won’t be the last. No fewer than 76 CAR-T treatments are currently under review at the FDA, and Gottlieb predicted other approvals would follow.
Therapies that would operate in similar ways – engineering T cells to fight disease more effectively – are under investigation for a host of other conditions, including HIV/AIDS, genetic and autoimmune disorders and other forms of cancer.
“Today’s FDA ruling is a milestone,” said Dr David Maloney, medical director of cellular immunotherapy at Fred Hutchinson Cancer Research Center in Seattle.
“This is just the first of what will soon be many new immunotherapy-based treatments for a variety of cancers.”
Novartis, which is gearing up to provide Kymriah to as many as 600 patients a year, said it would charge US$475,000 (RM1.99mil) for the treatment.
Novartis representatives said they calculated a “cost-effective price” for the therapy that fell between US$600,000 and US$750,000 (RM2.5mil and RM3.14mil).
But the company chose instead to charge a price that it said would “cover costs”, and to introduce a novel approach to billing.
Chief executive Joseph Jimenez said the company would not charge hospitals for the therapy if the patient didn’t fully respond in a given period of time.
The company also said it would launch a patient assistance programme for those who were uninsured or underinsured, and provide some travel assistance for patients and caregivers seeking the treatment.
Novartis’ application for Kymriah came just seven months ago.
The agency tagged the application with two designations that ensured its speedy review.
First proposed in 1972, the idea of correcting or enhancing genes to treat disease has a history buoyed by promise, but also buffeted by failures.
With recent advances in genomic medicine, cell biology and genetic engineering, efforts to locate and edit the genes and cells that play a key role in disease have injected new hope for such treatments.
Gene and cell therapies that target the immune system for enhancement have been particularly promising.
They do, however, come with risks – specifically, that the activation of immune cells will run amok, sparking reactions ranging from rash and itching to fever and flu-like symptoms that can lead to death.
In approving Kymriah, the FDA warned it had the potential to cause severe side effects, including cytokine release syndrome, an overreaction to the activation and proliferation of immune cells that causes fever and flu-like symptoms, and neurological events. Both can be life-threatening.
The FDA called for continuing safety studies of the new therapy. — Los Angeles Times/Tribune News Service
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