Vertex, CRISPR Therapeutics’ blood disorder gene therapy shows more promise

New data presented at the European Hematology Association 2021 (EHA) virtual congress shows patients treated with Vertex/CRISPR Therapeutics’ blood disorder gene therapy CTX001 had ‘sustained response[s]’ to treatment’.

The new data included 22 patients with at least three months of follow-up who were treated with Vertex/CRIPSR Therapeutic’s investigational CRISPR/Cas-9-based gene therapy CTX001.

Of these patients, 15 have transfusion dependent beta thalassemia (TDT) – six of who have the beta zero/beta zero or other severe genotypes. The remaining seven patients included in these results have severe sickle cell disease (SCD).

According to the data presented at EHA, all 15 patients with TDT were transfusion-free with follow-up ranging from four to 26 months after CTX001 dosing.

The patients also had clinically meaningful improvements in total haemoglobin from 8.9 to 16.9 g/dL and foetal haemoglobin from 67.3% to 99.6% at last visit.

In addition, all seven SCD patients remained of vaso-occlusive crises (VOCs) with follow-up ranging from five to 22 months after CTX001 infusion and had clinically meaningful improvements in total haemoglobin from 11 to 15.9 g/dL and foetal haemoglobin levels from 39.6% to 49.6% at last visit.

“The data presented today in 22 patients are impressive in both the consistency and durability of effect,” said Reshma Kewalramani, chief executive officer and president at Vertex.

“These results add to the growing body of evidence that CTX001 may hold the promise for a one-time functional cure for sickle cell disease and beta thalassemia. We are working with urgency to complete enrolment and look forward to finalizing regulatory discussions and moving towards filing.”

In April, the European Medicines Agency (EMA) granted CTX001 a Priority Medicines (PRIME) designation.

A PRIME designation provides early support to the developers of ‘promising medicines’ in a bid to optimise development plans and accelerate evaluations to improve patient access.