Dr. Stéphanie Cherqui provided an update on the stem cell gene therapy trial at the 2022 Day of Hope Family Conference. Five patients have now received the transplant, and she has good follow-up data on two of them. White blood cell cystine levels in these patients have gone down to normal despite not being on cysteamine. This makes sense since the white blood cells come from the transplanted bone marrow, but is the same effect seen in the other tissues? That is the million-dollar question! Dr. Cherqui showed us that skin and rectal biopsies do show a reduction in cystine crystals, and so do images of the corneas. This suggests that the stem cells are assisting other cells in the body too, as she previously showed in mice. Another curious change they noted was that patient one and patient three have darker hair color now, which is not unusual after chemotherapy but may also suggest a correction in previously impaired melanin synthesis. Overall, the results were inspiring and hopeful.
