Although the FDA is not bound to follow recommendations from its advisers when making decisions on treatments it usually does, and is due to make a decision on CTL019 in September following a six-month priority review.
CAR-T is a novel therapy and could lead to changing the treatment standards for cancer.
The Alliance for Cancer Gene Therapy supported the Novartis' experimental CAR-T therapy called Tisagenlecleucel, or CTL019, a statement from the alliance noted. "This is a major advance, and is ushering in a new era", said Malcolm Smith, a paediatric oncologist at the National Institutes of Health in Bethesda, Maryland.
The approval of the new treatment has potential consequences that extend well beyond treatment of leukemia.
Cytokine release syndrome (CRS), a potentially life threatening inflammatory response, and neurological toxicity are the two main safety concerns with CAR-T, seen across studies of different therapies.
While many patients can be cured with existing treatments, around 15%-20% see their disease return, and most of these relapsed patients do not survive. In 2012 as a 6 year old, she was treated in a study at the Children's Hospital of Philadelphia.
Principal supporting data for the application came from a phase II trial of children and young adults with relapsed/refractory ALL, given a single infusion of CTL019. Others are expected: Researchers and drug companies have been engaged in intense competition for decades to reach this milestone.
CAR-T therapies also present a gnarly regulatory challenge for the FDA: how do you assure the potency and purity of a complex, living drug that must be made fresh for each patient? Although analysts predict that the cost of these unique treatments may exceed $300,000, a Novartis spokesman declined to specify a price when NYT inquired.
More than 600 patients in the U.S. each year reach that critical stage. At that point, they have limited options - all more toxic than the CAR-T therapy - and survival chances are slim. Of 52 patients who results were analyzed, 83 percent had complete remission. In light of the drug's side effects, the FDA advisory panel viewed this as a favorable risk-benefit balance. Eleven patients, however, died. Gene therapies, this camp might argue, require more editing, and CAR-T is simply a cell therapy. In a lab, a gene is then inserted into the T cells that prompts them to grow a receptor that targets a special marker found on some blood cancer cells. The technique employs a disabled form of HIV, the virus that causes AIDS, to carry new genetic material into the T-cells to reprogram them.
"Although this therapy is technologically somewhat complicated and is associated with certain serious side effects, it indeed has been proven to be amazingly effective", said Dr Kanti Rai, chief of the chronic lymphocytic leukaemia research and treatment programme at Northwell Health Cancer Institute in NY. The CTL019 also secured FDA breakthrough therapy status and is under priority review by the FDA.
Approval of tisagenlecleucel would have implications not only for Novartis, but for companies developing similar treatments, including Kite Pharma Inc, Juno Therapeutics Inc and bluebird bio Inc. A total of 82.5% of the patients went into remission, which is a high rate for the disease.