Despite One Death and One Adverse Event, bluebird bio's Gene Therapy Study Meets Goals

Despite One Death and One Adverse Event, bluebird bio (BLUE)'s Gene Therapy Study Meets Goals October 5, 2017
By Alex Keown, Breaking News Staff

CAMBRIDGE, Mass. – Despite the death of one patient, bluebird bio’s Lenti-D gene therapy treatment for patients with cerebral adrenoleukodystrophy (CALD) could be a viable option for treating the potentially fatal genetic disease, researchers said.

Interim data from a 17-patient Phase II/III study at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center indicates the gene therapy is meeting its primary endpoints of keeping the children alive and free from major functional disabilities (MFD) associated with the disease. Cerebral adrenoleukodystrophy, also known as Lorenzo’s Oil disease, involves a breakdown of the protective sheath of the nerve cells in the brain that are responsible for thinking and muscle control. The disease affects one in every 21,000 male births worldwide and can be fatal.

The patients received a one-time treatment with Lenti-D and were observed for a period of at least 24 months. According to the data, which was published in the New England Journal of Medicine, 88 percent of the patients were successfully responding to the treatment. Of the 16 living patients, none of them experienced any of the six MFDs, which include loss of communication, cortical blindness, tube feeding, total incontinence, wheelchair dependence and complete loss of voluntary movement.

Two of the patients in the study did not meet primary endpoints. One patient had not experienced an MFD, but withdrew from the study due to radiographic progression of disease and underwent allogeneic hematopoietic stem cell transplantation (HSCT). He subsequently died from complications of the allogeneic transplantation, bluebird said.

The second patient was the one who died during treatment. Bluebird said he had rapid disease progression that began early in his participation in the study. That resulted in multiple MFDs, as well as a Neurologic Function Score of 15.

“The rapidity of his disease progression suggests it would have been difficult to alter his early neurological decline given that Lenti-D treatment takes months to exert a therapeutic effect in CALD,” bluebird said.

David Williams, the chief scientific officer and president of Dana-Farber, said the interim data suggests that Lenti-D may be a viable option to treat CALD patients. He said the gene therapy, which is autologous, could potentially overcome some of the challenges associated with allogeneic stem cell transplantation, which is the current standard of care for CALD patients.

“Not only does the data show that Lenti-D has the potential to minimize further progression of this devastating disease, but the technique also avoids the need for a matched bone marrow donor, which can be difficult to find and can delay vital treatment,” Adrian Thrasher, a professor of immunology and co-investigator of the study, said in a statement.

Thrasher went on to note that because of the encouraging results from the trial, it could “pave the way” for additional development of state-of-the-art treatments for children with genetic disease such as CALD.

Despite the promising results of the CALD study, bluebird investors have remained a bit lackluster today. Shares of bluebird are trading at $126.35 as of 11:32 a.m.

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