bluebird bio says 'very unlikely' AML events are linked to its gene therapy

Shares of US biotech bluebird bio (Nasdaq: BLUE) gained 13% pre-market today and were still up 8.8% at $32.70 by mid-morning after it announced encouraging analyses of its gene therapy program that was linked with a serious adverse event.

As a result of the emergence of possible problems last month, the US Food and Drug Administration placed a clinical hold on the HGB-206 and HGB-210 studies of LentiGlobin for SCD and the HGB-207 and HGB-212 studies of Zynteglo (betibeglogene autotemcel) for β-thalassemia.

Bluebird said that, based on the analyses completed to date, it is very unlikely the Suspected Unexpected Serious Adverse Reaction (SUSAR) of acute myeloid leukemia (AML) reported in its Phase I/II (HGB-206) study of LentiGlobin gene therapy for sickle cell disease (SCD) (bb1111) was related to the BB305 lentiviral vector (LVV).