Why Are Bluebird Bio Shares Trading Lower Today?

The FDA has placed a partial clinical hold on Bluebird bio Inc's BLUE lovotibeglogene autotemcel (lovo-cel) gene therapy program for sickle cell disease (SCD) for patients under the age of 18.
The partial, temporary suspension relates to an ongoing investigation by bluebird bio into an adolescent patient with persistent, non-transfusion-dependent anemia following treatment with lovo-cel, now 18 months post-treatment.
The patient is clinically well, and there is no evidence of malignancy or clonal predominance.
Related: Bluebird bio's Neurodegenerative Disease Gene Therapy Under Priority FDA Review, Despite Clinical Hold.
Bluebird anticipates receiving written questions from the agency in early 2022.
Enrollment and dosing for patients 18 and older living with SCD in the HGB-206, HGB-210, and LTF-307 clinical studies and follow-up for treated patients of all ages in all studies continue as planned.
The Company is evaluating the impact of the partial clinical hold on Q1 of 2023 projected timing for the lovo-cel biologics license application (BLA) submission.
Lovo-cel gene therapy is designed to add functional copies of a modified form of the β-globin gene into a patient's hematopoietic (blood) stem cells.
Price Action: BLUE shares are down 20.70% at $8.42 during the premarket session on the last check Monday.