Vertex's CRISPR treatment for sickle cell disease hits unexpected roadblock

Cell-collection continues to be challenging for gene-editing companies to execute clinically.

“Some patients have had to come in for five different hospital stays. A small percentage have given up during the journey or been told by physicians that they are unlikely to ever have enough cells to be treated, devastating news for patients who were hoping to be cured.

A spokesperson added that Vertex tells centers to expect roughly 24 weeks from the first collection to finished product and that ‘in the vast majority of cases, this target is hit’ and that ‘the turnaround is usually shorter.’ But the company declined to share actual data.”

One advantage Bluebird's Lyfgenia has over Vertex’s Casgevy in that it requires fewer cells to be collected for gene correction, although they also has issues with collection. Effectively collecting HSCs remains a sticking point despite developments in mobilization and collection techniques. Multiple collections and collection cycles is always going to be tough to operationalize on actual patients.