Crispr didn't cure the cancer, the bone marrow transplant did; bone marrow transplants (without Crispr) are the standard of care for treating this cancer. The f

Crispr didn't cure the cancer, the bone marrow transplant did; bone marrow transplants (without Crispr) are the standard of care for treating this cancer. The fact that the bone marrow transplant was necessary for the cancer gave the researchers an opportunity to also try out this HIV treatment, which requires a bone marrow transplant that would ordinarily be too high-risk to be justifiable on its own. This was a very early-stage trial, probably not expected to be curative; they were just seeing if the method in general was safe, and did anything. It apparently was safe, and successfully conferred the desired mutation to at least some of the patient's immune cells (so it did something), but not enough of them to be curative. It sounds like future trials will focus on improving efficacy.