An advisory panel to the Food and Drug Administration earlier this week unanimously recommended approving a breakthrough genetic therapy to treat a rare but deadly type of childhood cancer.

Here's why the news has cancer researchers excited—and what it means for families with children diagnosed with the cancer.

What Is the New Gene Therapy?

The new therapy, developed by the Swiss drug company Novartis, is known as as CTL019 (tisagenlecleucel). It’s sometimes referred to as a “living drug,” because it relies on using a patient's own immune system to fight cancer. Doctors take a type of white blood cell called T-cells from a patient’s bloodstream, genetically modify them to attack cancer cells (as shown in the image above), then infuse them back into the patient.

“This opens up a whole new world for cancer research and treatment,” says Gwen Nichols, M.D., chief medical officer of the Leukemia & Lymphoma Society, a nonprofit organization that helped fund research on the therapy.

Who Might Benefit From It?

The drug is meant to help children with B-cell acute lympoblastic leukemia (ALL) who don't respond to chemotherapy, radiation, and other existing treatments. There are about 2,500 cases of ALL in the U.S. each year, and about 620 children who don't recover with that standard care.

The FDA advisory panel recommended approval based mainly on a Novartis trial, which found that among 63 such patients treated with CTL019, 52 went into remission.

The therapy is intended as a last resort for children who “would otherwise die in a matter of weeks,” Nichols says. That's because the therapy, while potentially lifesaving, also carries serious risks, including a life-threatening reaction called cytokine release syndrome. 

When Will the Therapy Be Available?

The FDA will make a final decision on the drug by October 2017, according to Novartis spokesperson Julie Masow.

The approval of the therapy is contingent upon Novartis' response to a number of issues, including chemistry, manufacturing, and safety questions.

CTLO19 was designated as a "breakthrough therapy" by the FDA back in 2014, which the agency grants to drugs that treat serious or life-threatening conditions and that demonstrate the potential to be significantly more effective than existing therapies.

But because of the complexity and novelty of the CTL019, says Masow, it will initially be offered at just 30 to 35 treatment centers in the U.S.

"This strategy will help ensure that each site is fully prepared with the necessary infrastructure in place to support the special ordering, cell collection, chain of identity, use, and site-level care associated with CTL019," Masow says.  

How Much Will It Cost?

That's unclear, but it's expected to be very expensive.

Novartis has not announced how much it will charge for the drug therapy if it's approved. But Reni Benjamin, a biotechnology analyst for the financial services company Raymond James who tracks the gene therapy market, estimates the price will be set at around $450,000 for the one-time treatment.

Though that may sound exorbitant, Nichols points out that the therapy is complex and "has to be done in a specialized medical center and patients have to be hospitalized and carefully monitored for several days," she says.

Novartis' Masow told us that the “price of CTL019 will take into consideration the value this innovative treatment brings to patients, society and the healthcare industry, both near-term and long-term” and that the company is "committed to doing everything we can to ensure that patients who can benefit from CTL019 will have access to therapy."

That could include assistance with costs, if needed, Masow says.

Will Insurance Cover It?

Private insurers, and Medicaid, have not yet said whether they will cover the therapy. But Benjamin suspects they will, pointing out that the therapy will be used on a small number of patients. "The drug companies are talking to the payers, and at this point it seems that the payers are onboard with covering it." 

Editor's Note: This article and related materials are made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multistate settlement of consumer-fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).