Data from two patients in an ongoing phase I/II clinical trial of LentiGlobin BB305, a gene therapy for sickle cell disease (SCD), suggest that improvements to the manufacturing process for the gene therapy improved normal red blood cell production in these patients.
With LentiGlobin BB305, a normal beta globin gene is transported into a patient’s hematopoietic stem cells ex vivo before the modified stem cells are infused back into the patient’s blood. Following disappointing clinical trial results two years ago, the gene therapy manufacturing process was revamped to increase the percentage of patient stem cells that carry the corrected, functional gene. The conditioning regimen was also modified to increase the likelihood the functional genes engraft into patients’ bone marrow.
After three months, one of the patients showed blood levels of hemoglobin A that are higher than any patient previously treated in the study. It is too early to assess hemoglobin A levels in the second patient. Updates on both patients will be presented at the 2017 American Society of Hematology Annual Meeting.
Source: STAT News, November 1, 2017.