Vertex and CRISPR’s functional cure: room to improve?
The partners’ sickle cell and β-thalassemia data raise questions for competitors on mechanism, safety and price
Vertex and CRISPR’s latest data have set both proof of concept and a high bar for the growing crop of companies taking on sickle cell disease and β-thalassemia with gene editing technologies. Whether next-generation editing strategies will have longer lasting effects remains an open question, but in vivo editing has the clearest opportunity to move the needle on accessibility.
In a June 12 presentation during the European Hematology Association’s (EHA) virtual meeting, Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) and CRISPR Therapeutics AG (NASDAQ:CRSP) said the ex vivo gene edited hematopoietic stem cell (HSC) therapy exagamglogene autotemcel (exa-cel, CTX001) led to no vaso-occlusive crises in all 31 severe sickle cell disease patients, and transfusion independence in 42 out of 44 (95%) of β-thalassemia patients who were previously dependent on the procedure; the remaining two had 75% and 89% reductions in transfusion volume. The 75 patients in the Phase I/II study had follow-up ranging from 1.2-37.2 months after dosing, and 33 had been followed for a year or more...