Bluebird bio Inc. said its gene therapy Lenti-D helped prevent the onset of disabilities in patients with a rare neurogenerative disease.
The Cambridge, Mass.-based clinical-stage biopharmaceutical company evaluated Lenti-D for its efficacy and safety in a phase 2/3 trial of 32 patients with cerebral adrenoleukodystrophy, or CALD, which is a rare metabolic disorder linked with a mutation in the X chromosome.
The progressive neurogenerative disease involves the breakdown of the protective sheath of nerve cells in the brain. Symptoms of the disease occur in early childhood and if untreated, the disease leads to a severe loss of neurologic function followed by death in most patients. The disease is estimated to affect one in 21,000 male newborns worldwide.
Bluebird presented updated results from the Starbeam Study, also called ALD-102. The primary goal of the study is the proportion of patients alive and free of major functional disabilities, or MFDs, at month 24 of the treatment. MFDs are characterized by severe disabilities in patients, which include loss of ability to communicate, cortical blindness, need for tube feeding, total incontinence, wheelchair dependency and complete loss of voluntary movement.
Out of the 17 patients who completed 24 months in the study, 15 patients, or 88%, continued to survive and be MFD-free and are now enrolled in a long-term follow-up study called LTF-304. The 14 patients who have not yet completed 24 months in the study show no signs of MFDs. However, one patient experienced rapid disease progression that resulted in MFDs and death.
In addition, three out of the 32 treated patients did not or will not meet the primary goal and two patients withdrew from the study at investigator discretion.
The primary safety goal for the trial is the proportion of patients who experience acute or chronic graft-versus-host disease, or GvHD, by month 24. This is a condition that may occur after allogeneic hematopoietic stem cell transplant, or allo-HSCT, where donated cells attack the recipient's body. No events of GvHD and graft failure were reported after the Lenti-D treatment.
The company also presented updated results from an observational study, named ALD-103, of allo-HSCT in 47 patients 17 years of age and younger with CALD. The updated results showed that early treatment with allo-HSCT improved overall and MFD-free survival for patients with CALD.
In total, 23.5% and 27.6% of patients experienced acute and chronic GvHD, respectively. The overall rates of 100-day and one-year deaths in patients who received the transplant were 0% and 12.1%, respectively. The overall rate of engraftment failure by month 24 was 21.6%.
Bluebird's Lenti-D previously received orphan drug status, a breakthrough therapy designation and the rare pediatric disease designation for the treatment of CALD from the U.S. Food and Drug Administration. The European Medicines Agency accepted the therapy for the treatment of CALD into its Priorities Medicines Scheme in July 2018 and has granted it the orphan medicinal product designation.
