Teen in Remission After Experimental Base-Edited Cell Therapy and Second Transplant

Alyssa Tapley entered remission after receiving an experimental CRISPR base-edited CAR T-cell therapy at Great Ormond Street Hospital following the failure of standard treatments for T-cell leukemia. @NewScientist reported that Tapley, who turned 13 in 2021, was diagnosed after presenting with double pneumonia and breathing difficulties.

She had begun experiencing extreme fatigue and difficulty walking home from school after returning following the coronavirus lockdown.

She spent several days in intensive care and started chemotherapy at Leicester Royal Infirmary after Easter 2021. The initial chemotherapy regimen did not work, and a more intense course also failed. At the end of October 2021 she underwent a bone marrow transplant at Sheffield Children’s Hospital.

The transplant did not succeed, and doctors informed her parents she had only weeks to live. Tapley was then enrolled in a clinical trial run by Professor Waseem Qasim and overseen by Doctor Robert Chiesa. The trial used CRISPR base editing to modify CAR T-cells so they would not attack each other.

She received two weeks of conditioning chemotherapy before the infusion. One week after infusion the modified cells had multiplied. Four weeks after infusion bone marrow testing showed no detectable cancer cells.

Six weeks after infusion she underwent a second bone marrow transplant to replace blood stem cells. She developed an underactive thyroid attributed to prior chemotherapy. Tapley turned 17 in January and is studying for A-levels while learning to drive.

She remains in remission and has met Professor David Liu, who developed base editing, at a conference. The interview was conducted by Michael Le Page for New Scientist.