CRISPR Therapeutics and Vertex Announce New Clinical Data for Investigational Gene-Editing Therapy CTX001 in Severe Hemoglobinopathies at the 25th Annual European Hematology Association (EHA) Congress - Seite 2

Patient 2 with TDT has the β0/IVS-II-745 genotype and had a transfusion requirement of 61 units of packed red blood cells per year (annualized rate during the two years prior to consenting for the trial) before enrolling in the clinical trial. The patient achieved neutrophil engraftment 36 days after CTX001 infusion and platelet engraftment 34 days after infusion. After CTX001 infusion, two SAEs occurred, neither of which the PI considered related to CTX001: pneumonia and an upper respiratory tract infection; both subsequently resolved. At 5 months after CTX001 infusion, the patient was transfusion independent and had total hemoglobin levels of 12.5 g/dL, fetal hemoglobin of 12.2 g/dL, and F-cells (erythrocytes expressing fetal hemoglobin) of 99.4%.

Hemoglobin data over time are presented for Patient 1 and Patient 2 below.

Figure 1 accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/35581299-d683-44b0 ...

CLIMB-121 Trial in Severe Sickle Cell Disease Updated Results
Data presented today at EHA reflect longer-duration follow-up data for the first patient with SCD treated with CTX001. CRISPR Therapeutics and Vertex announced initial data for this first SCD patient in November of 2019.

Patient 1 with SCD experienced seven vaso-occlusive crises (VOCs) and five packed red blood cell transfusions per year (annualized rate during the two years prior to consenting for the trial) before enrolling in the clinical trial. As previously reported, the patient achieved neutrophil and platelet engraftment 30 days after CTX001 infusion. After CTX001 infusion, three SAEs occurred, none of which the PI considered related to CTX001: sepsis in the presence of neutropenia, cholelithiasis and abdominal pain; all subsequently resolved. New data presented today show that at 9 months after CTX001 infusion, the patient was free of VOCs, was transfusion independent and had total hemoglobin levels of 11.8 g/dL, 46.1% fetal hemoglobin, and F-cells (erythrocytes expressing fetal hemoglobin) of 99.7%. Bone marrow allelic editing was 81.4% at 6 months. Figure 2 presents the hemoglobin data over time for this patient.