Vertex, CRISPR update long-term data for gene edited therapy in blood disorders
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U.S. biotech Vertex (VRTX) and Swiss gene-editing company CRISPR Therapeutics AG (NASDAQ:CRSP) announced updated data for geneâedited therapy exa-cel on Saturday, highlighting its potential to become a one-time therapy for beta-thalassemia and sickle cell disease.
The data from ongoing Phase 1/2/3 openâlabel trials, CLIMBâ111 and CLIMBâ121, and longâterm, openâlabel trial, CLIMB-131, included follow-up periods ranging from 1.2 to 37.2 months after receiving exa-cel, formerly known as CTX001.
Vertex (VRTX) and CRISPR (CRSP) have partnered for the development and commercialization of the CRISPR/Cas9-based gene editing therapy.
The results were part of a presentation at the 2022 European Hematology Association (EHA) Congress. It highlighted the outcome of 75 patients: 44 with transfusion-dependent beta-thalassemia (TDT) and 31 with severe sickle cell disease (SCD).
Out of 44 patients with TDT, 42 were transfusion free after receiving exa-cel with follow-ups ranging from 1.2 to 37.2 months. The other two patients had transfusion volumes dropped by 75% and 89%, the companies said.
The patientsâ mean total Hb levels increased up to >11 g/dL by Month 3 and maintained thereafter, indicating the potential of exa-cel to cut transfusion requirements, according to the companies. However, two patients in the TDT group had serious adverse events (SAEs) related to the study drug.
SCD data indicated that all 31 patients characterized by recurrent vaso-occlusive crises (VOCs) were free from the manifestation after receiving exa-cel with follow-up ranging from 2.0 to 32.3 months.
The patients achieved a mean HbF level (as a percentage of total hemoglobin) of 40% by month 4 and retained that level thereafter. The increase in HbF indicates the potential of exa-cel to cut disease severity in SCD. None of the patients had SAEs related to exa-cel.
Additionally, following regulatory feedback, the investigators have changed the trial protocols of CLIMB-111 and CLIMB-121 trials to reflect a change to primary endpoints.
Both trials have been fully enrolled with participants having the option to join the CLIMB-131 long-term follow-up study after the initial studies.
In June 2021, Vertex (VRTX) and CRISPR (CRSP) shared data for 22 patients with a follow-up period of at least 3 months.