Shares of Bluebird Bio (NASDAQ:BLUE) slipped Monday in the wake of the unveiling of new data which evaluated the company’s LentiGlobin gene therapy in patients with both transfusion-dependent B-Thalassemia, a blood disorder that reduces hemoglobin production, and sickle cell disease, a red blood cell disorder.
The data showed that eight of 10 patients with B-Thalassemia, who were treated with LentiGlobin in Bluebird’s Northstar study achieved transfusion independence, which means they had not received a transfusion for at least 12 months and maintained hemoglobin greater than 9 grams per deciliter. The biotech’s data also showed that excess iron levels in the liver, which are caused by repeated transfusions and can be toxic, had also started to diminish.
In separate news, results from a continued open-label Phase 1/2 clinical trial in patients with sickle cell disease demonstrated hemoglobin production of 0.7 to 2.8 g/dL in the first group of seven patients who also maintained stable total hemoglobin levels ranging from 7.6 to 11.8 g/dL. These hemoglobin levels fell below the normal level of hemoglobin posted by healthy men and women. But the treatment effect was better in Group B patients, with hemoglobin production ranging from 3.4 to 6.5 g/dL and total hemoglobin levels staying stable at 11to 12.3 g/dL.
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“These higher rates of total hemoglobin and HbA (adult hemoglobin) production in Group B are attributed to the implementation of a refined drug product manufacturing process and protocol modifications to improve engraftment of genetically-modified stem cells,” according to Bluebird’s release.
Serious adverse event reported in one study
Another negative was that a serious adverse event was reported in a patient with sickle cell disease who received LentiGlobin about three years ago in Group A of the Phase 1/2 HGB-206 study and came down with myelodysplasia syndrome, a bone marrow disease.
“[The] independent data monitoring committees, along with the treating physician, agreed the serious adverse effect was unlikely related to LentiGlobin gene therapy,” the company said in a release.
The results were presented at the 60th American Society of Hematology annual meeting in San Diego.
With its lentiviral-based gene therapies, T cell immunotherapy and gene editing capabilities, bluebird bio has built a pipeline with broad potential applications for severe genetic diseases and cancer.
Investors sent Bluebird Bio shares down 5.7% to $115.92 in Monday’s afternoon trading session.
Contact Ellen Kelleher at [email protected]