bluebird bio Touts Impressive Data From Late-Stage Gene Therapy Study

Published: Jun 26, 2017

bluebird bio Touts Impressive Data From Late-Stage Gene Therapy Study June 23, 2017
By Alex Keown, BioSpace.com Breaking News Staff

CAMBRIDGE, Mass. – bluebird bio ’s interim data for its Phase III gene therapy LentiGlobin trial showed promising results in reducing a patient’s need for blood transfusions after one month after treatment, but the data also raised some concerns.

Those concerns have caused share prices of bluebird to fall nearly 10 percent as of 9:35 a.m. today. Shares of bluebird are trading at $106.50, down from $117.35 on Thursday.

The interim bluebird data is for the anticipated Northstar-2 trial using LentiGlobin to treat patients with transfusion dependent beta-thalassemia, an inherited blood disease that can be fatal due to severe anemia. The company shared information on three patients ahead of the European Hematology Association meeting.

In the data released this morning, bluebird said one of the patients treated with its updated LentiGlobin product was able to cease regular blood transfusions one month after treatment and achieved normal hemoglobin levels within six months. Overall the three patients achieved in vivo vector copy numbers and higher production of HbAT87Q that are “as good as or better” than transfusion patients, the company said.

However, bluebird also said a follow up with two of the patients following treatment failed to show significant levels of hemoglobin to be clinically relevant. While investors have seen this as a red flag, bluebird researchers pointed to the positive response of the first patient as a positive sign for the promise of gene therapy.

“The first patient treated in this study exemplifies the promise of gene therapy, discontinuing blood transfusions approximately a month after treatment and achieving a normal level of total hemoglobin production at six months post-treatment,” David Davidson, bluebird bio’s chief medical officer, said in a statement. “These early results suggest that the improved manufacturing process results in consistently higher drug product vector copy numbers and lentiviral vector positive cells, which is correlated with higher production of HbAT87Q and ultimately may address known patient-to-patient variability.”

LentiGlobin was granted Breakthrough Therapy Status by the U.S. Food and Drug Administration (FDA). The designation is given to drugs expected to treat life-threatening illnesses in order to expedite the development and review of the drug.

Two years ago the company presented data at the American Society of Hematology that indicated LentiGlobin worked differently in individual patients, which meant that single conclusive results could not be achieved. Those mixed results sent bluebird back to the lab to continue working on LentiGlobin.

Nick Leschly, bluebird’s chief executive officer, told Adam Feuerstein of Stat News, that the interim data is exciting news. In his interview with Stat, Leschly said bluebird is “on track to be among the first biotechs to successfully develop and market a curative gene therapy for rare, inherited blood diseases.”

While Leschly is excited, that doesn’t mean investors are, nor does it mean the drug is ready to be presented to the FDA. There is still a ways to go and more data to come, data that could turn around the concerns of bluebird investors. LentiGlobin is also being explored for the treatment of sickle cell disease.

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