A 13-year-old girl is in remission after becoming the first patient in the world to receive ground-breaking gene therapy for previously incurable leukemia.
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 which allowed doctors to use healthy, altered cells, to hunt down and kill the cancerous T-cells without attacking each other.
Six months later, Alissa is cancer-free.
We were joined by Alissa and her mother, Kiona.