The US Food and Drug Administration (FDA) just approved a cutting-edge cancer therapy.

On Wednesday, the FDA approved Novartis's Kymriah, also known as tisagenlecleucel, a treatment for pediatric acute lymphoblastic lymphoblastic leukemia.

"I think this is most exciting thing I've seen in my lifetime," Dr. Tim Cripe, an oncologist who was part of the FDA advisory committee panel that voted in favour of approving the drug in July.

The highly personalised treatment is called CAR T-cell therapy. It's a type of cancer immunotherapy — or a therapy that harnesses the body's immune system to take on cancer cells.

"We're entering a new frontier in medical innovation with the ability to reprogram a patient's own cells to attack a deadly cancer," FDA commissioner Scott Gottlieb said in a statement.

"New technologies such as gene and cell therapies hold out the potential to transform medicine and create an inflection point in our ability to treat and even cure many intractable illnesses. At the FDA, we're committed to helping expedite the development and review of groundbreaking treatments that have the potential to be life-saving."

Short for chimeric antigen receptor T-cell therapy, CAR-T treatment takes a person's own cells, removes them from the body, re-engineers them, and then puts the cells back in the body where they can attack cancer cells.

Novartis' therapy is one of two cutting-edge treatments for blood cancers are poised to get approved by the end of the year.

The FDA is also expected to make a decision about another CAR-T treatment from Kite Pharma, which just got acquired by Gilead Sciences. That's for Kite's CAR-T treatment for aggressive B-cell non-Hodgkin lymphoma (more general than DLBCL).

In data Kite released in February, the company found that out of the 101 patients, 36 percent had a complete response to the treatment after six months.

It's a type of cancer that Novartis wants to get approval for in the future.

In June, Novartis released data from its Phase 2 trial of CTL019 in patients with diffuse large B-cell lymphoma (DLBCL for short), an aggressive form of lymphoma that's one of the two types Kite's data looks at. The trial found that of the 51 patients with DLBCL, 23 had either a complete response (meaning cancer had disappeared completely) or a partial response (meaning their tumour displayed signs that it was shrinking).

There are a some challenges facing new treatments like Kymriah:

  • The one-time treatments won't come cheap. While companies might price the drug based on how well it works, the price tag could still be more than US$300,000.
  • Manufacturing the drugs is no small feat, considering the personalised treatment requires taking out a person's cells, reprogramming them, then inserting them again. The company that's able to do that quickly and safely could have the advantage in the competitive CAR-T space.
  • These kinds of treatments have been deadly in the past. In May, Kite Pharma revealed that one person had died in a clinical trial for its late-stage CAR-T therapy from cerebral edema, a condition in which excessive fluid causes the brain to swell. And in July 2016, another CAR-T company, Juno Therapeutics, said four people in its clinical trials had died, all from cerebral edema.

This article was originally published by Business Insider.