Doctors in Britain have hailed a pioneering treatment for an aggressive form of leukemia after a teenager became the first patient to be given a new therapy and went into remission.
Alissa had undergone all conventional therapies and had no other treatment options available.
And then, she was enrolled in a clinical trial by Great Ormond Street Hospital using a new gene-editing technology that allowed doctors to use healthy, altered cells for hunting down and killing the cancerous T-cells without attacking each other.
Six months later, Alissa is cancer-free.
Acute lymphoblastic leukemia (ALL) is the most common kind of cancer in children and affects cells in the immune system, known as B cells and T cells, which fight and protect against viruses.
GOSH said Alyssa was the first patient to have been given base-edited T cells, which involve chemically converting single nucleotide bases – letters of the DNA code – which carry instructions for a specific protein.
Researchers at GOSH and University College London helped develop the use of genome-edited T cells to treat B-cell leukemia in 2015.
But to treat some other types of leukemia, the team had to overcome the challenge that T cells designed to recognize and attack cancerous cells had ended up killing each other during the manufacturing process.
Multiple additional DNA changes were needed to the base-edited cells to allow them to target cancerous cells without damaging each other.
"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," said GOSH consultant immunologist and professor Waseem Qasim.
"It's our most sophisticated cell engineering so far and paves the way for other new treatments and ultimately better futures for sick children."
Alyssa said she was spurred to take part in the trial not just for herself but for other children.
Her mother, Kiona, added: "Hopefully this can prove the research works and they can offer it to more children."
The researchers were presenting their findings this weekend at the annual meeting of the American Society of Hematology.