Overview

A teenage girl’s terminal cancer has been cleared from her body after a world-first use of a new experimental treatment called base editing. According to scientists, this new therapy is the “most sophisticated gene editing treatment” to date.

The science and other stuff to know

Alyssa, who was diagnosed with T-cell acute lymphoblastic leukemia, went through chemotherapy and an initial bone marrow transplant. Unfortunately, both treatments failed to clear her leukemia.

Instead of opting for palliative care, which is specialized medical care to optimize quality of life and mitigate suffering among people with serious illnesses such as cancer or heart failure, Alyssa decided to undergo an experimental treatment called base editing. She enrolled as the world’s first patient in the clinical trial at Great Ormond Street Hospital for Children (GOSH), where she received genetically modified CAR T-cells.

The cells, which originally came from a healthy donor, had been edited using base editing technology to allow them to hunt down and kill cancerous T-cells without attacking each other, according to GOSH. And within a month after receiving modified CAR T-cells, the young girl was in remission.

Speaking about the experimental new treatment, Robert Chiesa, one of the doctors who treated Alyssa, said in a statement, “This is quite remarkable, although it’s still a preliminary result, which needs to be monitored and confirmed over the next few months.”

So what?

While it’s still early to determine the full effectiveness analysis of the new treatment, scientists hope the experimental T-cell base editing technique could lead to new treatments and ultimately better futures for cancer patients.

“This is a great demonstration of how, with expert teams and infrastructure, we can link cutting-edge technologies in the lab with real results in the hospital for patients,” GOSH professor Waseem Qasim said. “It’s our most sophisticated cell engineering so far and paves the way for other new treatments and ultimately better futures for sick children.”

If the new treatment proves successful in future trials, it could be offered to patients “earlier in their cancer diagnosis” to kill cancerous T-cells. Scientists also aim to use base editing to treat other types of leukemia in the future.

What’s next?

Alyssa was the first to take part in the base editing clinical trial. Researchers at GOSH plan to recruit up to 10 patients with T-cell leukemia (who have exhausted all other treatment options) for the new treatment.