The US Food and Drug Administration (FDA) has granted breakthrough therapy designation to LentiGlobin® BB305 for the treatment of transfusion-dependent patients with beta-thalassemia major.
The product is created by inserting a functional human beta-globin gene into a patient’s hematopoietic stem cells ex vivo. The cells are returned to the patient via transplant.
The product is intended to treat sickle cell disease as well as beta-thalassemia major.
“The FDA’s breakthrough designation of LentiGlobin highlights that new therapies are needed for the treatment of patients with beta-thalassemia major, especially treatments with the potential to meaningfully reduce or liberate patients from transfusion dependence,” said David Davidson, MD, chief medical officer of bluebird bio, the company developing LentiGlobin.
“Our early clinical data investigating the use of LentiGlobin in patients with multiple genotypes of beta-thalassemia major . . . are very encouraging, and we remain on track to complete enrollment in the Northstar and HGB-205 studies in 2015.”
Early study results
The breakthrough designation is supported by data from the ongoing phase 1/2 Northstar (HGB-204) and HGB-205 studies. Findings in 8 subjects from both studies were presented at the 2014 ASH Annual Meeting.
As of December 1, five subjects with beta-thalassemia major had received LentiGlobin in the Northstar Study. The first 2 subjects were producing steadily increasing amounts of beta-T87Q-globin and were free of the need for transfusion for 5 months and 3 months, respectively.
Three additional subjects have received LentiGlobin as well, but researchers said it is too early to draw any meaningful conclusions on clinical efficacy.
As of December 1, two subjects with beta-thalassemia major received LentiGlobin as part of the HGB-205 study. Both achieved rapid transfusion independence with near-normal hemoglobin levels. And they were free from the need for transfusions for 12 months and 9 months, respectively.
The third treated subject, the first individual with sickle cell disease ever to be treated with gene therapy, has achieved neutrophil engraftment. But researchers said it is too early to draw any meaningful conclusions on clinical efficacy.
About breakthrough designation
The FDA’s breakthrough therapy designation is intended to expedite the development and review of a drug candidate intended to treat a serious or life-threatening condition.
For a drug to gain the designation, preliminary clinical evidence must suggest the drug could offer substantial improvement over existing therapies on one or more clinically significant endpoints.
The benefits of breakthrough designation include the same benefits as fast track designation (priority review, rolling review, etc.), plus an organizational commitment involving the FDA’s senior managers with more intensive guidance from the FDA.
Breakthrough therapy designation does not change the standards for approval.
