NHLBI Pauses SCD Gene Therapy Trial

February 24, 2021

The National Heart, Lung and Blood Institute (NHLBI) has paused participant enrollment and gene transfers in an NHLBI-funded trial at the Boston Children’s Hospital, Pilot and Feasibility Study of Hematopoietic Stem Cell Gene Transfer for Sickle Cell Disease, out of an abundance of caution. The pause follows a Feb. 16 announcement from Bluebird Bio that it had temporarily suspended clinical trials of a potential gene therapy for sickle cell disease (SCD) using a lentiviral vector after two patients who received the therapy developed cancer. 

NHLBI noted that the Boston Children’s Hospital trial was using a different, yet related, vector and targets a different gene than those targeted in the Bluebird trial. Furthermore, the agency noted that there have been no indications of such harm among the nine patients treated in the Boston Children’s Hospital trial. 

The agency requested that its data and safety monitoring board (DSMB) conduct an independent safety review of the NHLBI-funded Boston Children’s Hospital trial. NHLBI will reassess the pause after a thorough review of the Boston Children’s Hospital study by the DSMB and input from the Food and Drug Administration.