Right as Layla Richards turned a year old in June, doctors said there was nothing more they could do for her. Since she was 14 weeks old, Layla had been battling "one of the most aggressive forms" of acute lymphoblastic leukemia her doctors had seen; chemotherapy and a bone marrow transplant didn't work. Unwilling to accept palliative care, Layla's parents pleaded with doctors at Britain's Great Ormond Street Hospital to try anything that might help their daughter, reports the Washington Post. Then, a "lucky coincidence," reports the New York Times: The hospital was manufacturing "designer immune cells" that had never been used on humans and were to be tested in a clinical trial. They decided to use the cells on her—and they may have cured her. The hospital explains the science: Cancer patients' immune cells, or T-cells, can be modified to target and kill cancer cells, but leukemia typically destroys the healthy T-cells such that there aren't enough to harvest.
In this case, new genes were added to donor T-cells to "arm them against leukemia." "Molecular scissors" then cut certain genes to force two behaviors: The T-cells became "invisible to a powerful leukemia drug that would usually kill them" and were "reprogrammed to only target and fight against leukemia cells." For two weeks, nothing happened. Then Layla developed a rash, which showed her body was responding. A few weeks later, she was cancer-free and has been in the months since. "We thought that the little bit of liquid in the syringe was nothing" compared to the "bags and bags of chemo," says Layla's father of the 1ml infusion. Though it's apparently worked in only one patient who hasn't been in remission long, the Times frames the potential significance: "Cell therapies, which represent an exciting new front in the battle against cancer, might not have to be customized for each patient, saving time and money." (Elsewhere, researchers discovered a "one-two punch" against skin cancer.)