A Cure for a Childhood Cancer—but Will It Last?

Modifying a child’s immune system to fight off leukemia can yield dramatic results, but the treatments are dangerous and no one knows if they’re permanent.

Michael Reillyarchive page

October 5, 2016

The first time a child gets acute lymphoblastic leukemia it’s worrying, as any cancer would be, but generally curable. If it comes back, a bone marrow transplant could still wipe it out. If it comes back again, it is often a death sentence.

Or at least it was, until an experimental treatment that genetically enhances a patient’s immune system, known as CAR-T, came along. Only tested in humans in the last few years, the results have been astonishing, knocking out almost overnight a cancer that defied all other treatments. Early tests showed that 90 percent of patients went into remission.

There are, unfortunately, two major problems with CAR-T therapy. First, it is dangerous—deaths are not uncommon in clinical trials involving CAR-T. But for many patients the risk of a fatal reaction to the treatment is an acceptable one, given the potential benefit.

The second principal concern is that the cancer will come back. As a heartrending story in the Washington Post describes, by the time children enter into a CAR-T trial they (as well as the families that support them) have already been through hell. In the case of eight-year old Ava Christianson, the focus of the Post’s piece, the cancer survived even a round of CAR-T treatment, in which Ava’s immune cells were harvested from her, genetically modified, and given back to her. She was in for another, newer generation of the treatment, and it appeared to be working.

“We just need this to work and stay working for her,” her mom, Bethany Christianson, told the Post as she held back tears.

That’s the thing about CAR-T. Powerful as it is, it is such a new therapy that no one knows whether the effects are permanent—and if they aren’t, how long they last. Last year, we followed the story of one patient, Milton Wright III, who at 18 months had been one of the treatment’s longest survivors.

The phrase “a cure for cancer” has been around so long, it’s become cliché—a term invoked figuratively to describe a great achievement, or a panacea. As we approach such a cure, however, the reality is turning out to be far more fragile.