SAN FRANCISCO – Bluebird Bio Inc. reported that four young adults with beta-thalassemia major, a severe blood disorder that leads to life-threatening anemia, were able to produce sufficient hemoglobin to reduce or eliminate the need for chronic blood transfusions after being treated with its gene therapy, Lentiglobin BB305.
Though still early stage, the data sent Bluebird's shares (NASDAQ:BLUE) soaring 72.4 percent Tuesday, up $35.39 to close at $84.28. The stock has gained 215 percent since its Nasdaq debut in June 2013. (See BioWorld Today, June 20, 2013.)
The data, reported at the 56th Annual American Society of Hematology (ASH) meeting late Monday, hint at a potential new tool for battling the inherited illness. About 40,000 children are born with a serious form of beta-thalassemia major every year, making it one of the most common genetic diseases in the world, according to the Cambridge, Mass.-based company.
"For the first time, we know the most severe form of beta-thalassemia, beta-thalassemia major, can be treated – hopefully effectively – with a one-time infusion of Lentiglobin BB305," professor Alexis Thompson told BioWorld Today. Thompson, who teaches pediatrics at Northwestern University Feinberg School of Medicine and is the director of a thalassemia specialty program in Chicago, served as lead investigator for Northstar, one of the studies presented at ASH.
"If you can imagine, these are individuals who've been diagnosed in infancy. They've been on transfusions every three to four weeks for a lifetime and, as best we can tell, that is the only way for us to actually improve their survival," she said. "These are individuals who have constantly been tethered to medical facilities. If Lentiglobin BB305 continues to show promise, there really is a possibility of these patients being able to able to move forward without the burden of transfusions and chelation."
Lentiglobin aims to treat beta-thalassemia major and severe sickle cell disease by inserting a fully functional human beta-globin gene into the patient's own hematopoietic stem cells ex vivo and then transplanting those modified cells into the patient through infusion.
Bluebird highlighted data from the first five subjects treated in Northstar, an ongoing phase I/II study also known as HGB-204, and the first three subjects from its HGB-205 study. The studies include the first subjects with the beta-0/beta-0 genotype of beta-thalassemia major treated with Lentiglobin BB305, a beta-globin transduced autologous stem cell therapy, and the first subject with sickle cell disease treated with it.
The first two subjects treated in the Northstar study are producing steadily increasing amounts of beta-T87Q-globin and have been free from the need for transfusions for the past five months and three months, respectively, Bluebird said. Three additional subjects have been infused, but the company said it is too early to draw any meaningful conclusions on clinical efficacy in those cases.
In the HGB-205 study, two patients with beta-thalassemia major have undergone infusion with Lentiglobin BB305 and both had achieved rapid transfusion independence with near-normal hemoglobin levels. A third treated subject, the first person with sickle cell disease ever to be treated with the gene therapy, has achieved neutrophil engraftment, but was too early post-transplant for investigators to draw any meaningful conclusions on clinical efficacy, Bluebird said.
Between Jan. 1 and Sept. 30, Bluebird has incurred about $5.8 million in R&D expenses developing the Lentiglobin program, according to the company's most recent quarterly filing.