Benzinga | Dec 5, 2020 01:18PM EST

CRISPR Therapeutics and Vertex Present New Data for Investigational CRISPR/Cas9 Gene-Editing Therapy, CTX001 at ASH, Together With Publication in NEJM

CRISPR Therapeutics (NASDAQ:CRSP) and Vertex Pharmaceuticals Incorporated (NASDAQ:VRTX) today announced new data on a total of 10 patients treated with the investigational CRISPR/Cas9-based gene-editing therapy, CTX001, that show a consistent and sustained response to treatment. All seven patients with transfusion-dependent beta thalassemia (TDT), including three who have either a severe or b0/b0 genotype, were transfusion independent at last follow-up and all three patients with sickle cell disease (SCD) were free of vaso-occlusive crises (VOCs) from CTX001 infusion through last follow-up. These data will be presented during the Scientific Plenary at the annual ASH Meeting and Exposition on December 6, 2020. A summary of the results from the CLIMB-111 and CLIMB-121 Phase 1/2 clinical studies is provided below.

The companies also announced that The New England Journal of Medicine (NEJM) has published an independently peer-reviewed article entitled "CRISPR-Cas9 Gene Editing for Sickle Cell Disease and Thalassemia." The article includes detailed information on the first patient with TDT enrolled in CLIMB-111 and the first patient with severe SCD enrolled in CLIMB-121, at 18 and 15 months of follow-up, respectively.

CTX001 is being investigated in these two ongoing Phase 1/2 clinical trials as a potential one-time curative therapy for patients suffering from TDT and severe SCD.

"We are pleased with the data presented at ASH, which demonstrate potential benefit and durability among a larger population of patients with transfusion-dependent beta thalassemia and sickle cell disease," said Samarth Kulkarni, Ph.D., Chief Executive Officer of CRISPR Therapeutics. "Additionally, the NEJM case study is the first peer-reviewed journal publication for our CRISPR/Cas9 gene therapy, CTX001. Together this is further validation of the potential of CTX001 to become a best-in-class therapy. We plan to continue the rapid advancement of our clinical trials to bring these much-needed therapies to patients."

"These are the first published results from CRISPR/Cas9 therapy in people with a genetic disease and represent an important milestone in medicine and for our collaboration with CRISPR Therapeutics. Most importantly, these data represent a critical step in our effort to bring transformative and potentially curative therapies to patients," said Reshma Kewalramani, M.D., Chief Executive Officer and President, Vertex. "With clinical proof-of-concept for both beta thalassemia and sickle cell disease and 19 patients dosed, we look forward to continued efforts to bring our investigational treatment to patients living with TDT and SCD as quickly as we can."

"Our vision with this approach is to use the patient's own stem cells to provide a transformative treatment for these diseases, something almost unimaginable a few years ago," said Dr. Haydar Frangoul, M.D., Medical Director of Pediatric Hematology and Oncology at Sarah Cannon Research Institute, HCA Healthcare's TriStar Centennial Medical Center. "With these data in 10 patients, we can see the potential to fulfill this vision. With more data and longer duration of follow-up, we will hopefully confirm that we have a durable therapy that may transform the lives of many patients."

CLIMB-111 Trial in TDT: Updated ResultsA total of 13 patients with TDT have been dosed with CTX001, including eight additional patients since the last update in June 2020.

The seven patients with TDT reported at ASH are patients who had reached at least three months of follow-up after CTX001 dosing and therefore could be assessed for initial safety and efficacy. All seven patients showed a similar pattern of response, with rapid and sustained increases in total hemoglobin, fetal hemoglobin and transfusion independence at last analysis.

All seven patients were transfusion independent with follow-up ranging from three to 18 months after CTX001 infusion, with normal to near normal total hemoglobin levels at last visit, including total hemoglobin from 9.7 to 14.1 g/dL and fetal hemoglobin from 40.9% to 97.7%.

Bone marrow allelic editing data collected from four patients with six months of follow-up and from one patient with 12 months of follow-up after CTX001 infusion demonstrated a durable effect.

The safety data from all seven patients were generally consistent with an autologous stem cell transplant and myeloablative conditioning. There were four serious adverse events (SAEs) considered related or possibly related to CTX001 reported in one patient: headache, hemophagocytic lymphohistiocytosis (HLH), acute respiratory distress syndrome and idiopathic pneumonia syndrome. All four SAEs occurred in the context of HLH and have resolved. The majority of non-serious adverse events were considered mild to moderate.

CLIMB-121 Trial in Severe SCD: Updated ResultsA total of six patients with SCD have been dosed with CTX001, including four additional patients since the last update in June 2020.

The three patients reported at ASH are patients who had reached at least three months of follow-up after CTX001 dosing and therefore could be assessed for initial safety and efficacy. All three patients showed a similar pattern of response, with rapid and sustained increases in total hemoglobin and fetal hemoglobin, as well as elimination of VOCs through last analysis.

All three patients remained VOC-free with follow-up ranging from three to 15 months after CTX001 infusion and had hemoglobin levels in the normal to near normal range at last visit, including total hemoglobin from 11.5 to 13.2 g/dL and fetal hemoglobin levels from 31.3% to 48.0%.

Bone marrow allelic editing data collected from one patient with six months of follow-up and from one patient with 12 months of follow-up after CTX001 infusion demonstrated a durable effect.

The safety data from all three patients were generally consistent with an autologous stem cell transplant and myeloablative conditioning. There were no SAEs considered related to CTX001, and the majority of non-serious adverse events were considered mild to moderate.