BLA submission based on data from the largest and most mature clinical development program for any gene therapy in sickle cell disease

SOMERVILLE, MA, USA I April 24, 2023 I bluebird bio, Inc. (Nasdaq: BLUE) today announced the submission of its Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for lovotibeglogene autotemcel (lovo-cel) gene therapy in patients with sickle cell disease (SCD) ages 12 and older who have a history of vaso-occlusive events (VOEs). The BLA includes a request for Priority Review, which, if granted, would shorten the FDA’s review of the application to six months from the time of filing, versus a standard review timeline of 10 months. If approved, lovo-cel will be bluebird bio’s third ex-vivo gene therapy approved by the FDA for a rare genetic disease and its second FDA approval for an inherited hemoglobin disorder, building on more than a decade of leadership in gene therapy.

“The severity of sickle cell disease, and its impact on patients and caregivers, has been underappreciated and overlooked for far too long. Transformative therapies for this community are long overdue,” said Andrew Obenshain, chief executive officer, bluebird bio. “We are pleased to have satisfied the Agency’s questions about comparability to enable our BLA submission, and to take this important step toward making lovo-cel available for individuals living with SCD.”

Lovo-cel is the most deeply studied gene therapy in development for sickle cell disease. The BLA submission is based on efficacy results from 36 patients in the HGB-206 Group C cohort with a median 32 months of follow-up and two patients in the HGB-210 study with 18 months of follow-up each. The BLA submission also includes safety data from 50 patients treated across the entire lovo-cel program, including six patients with six or more years of follow-up.

The FDA previously granted lovo-cel orphan drug designation, fast track designation, regenerative medicine advanced therapy (RMAT) designation, and rare pediatric disease designation for the treatment of SCD.

About sickle cell disease (SCD)

Sickle cell disease (SCD) is a complex and progressive genetic disease associated with debilitating and unpredictable pain crises, irreversible damage to vital organs, and early death. In SCD, high concentrations of sickle hemoglobin (HbS) in red blood cells (RBCs) cause RBCs to become sickled, sticky, and rigid with a shorter life span, which manifests acutely as hemolytic anemia, vasculopathy, and vaso-occlusion. Pain onset can be sudden and unpredictable, often requiring hospitalization. Fifty to sixty percent of adults with sickle cell disease have end organ damage, with 24 percent experiencing damage in multiple organs, and one in four patients have a stroke by the age of 45. In the U.S., there are 100,000 people living with SCD, and half of people with SCD do not live past the age of 40.

SCD is also associated with lost educational, employment, and life opportunities for patients and caregivers. Complications of SCD impact every aspect of their lives – from work and school to the ability to complete daily tasks. The severity and burden of SCD has been historically underappreciated, and the community is long overdue for meaningful treatment advances.

About lovotibeglogene autotemcel (lovo-cel)

lovotibeglogene autotemcel (lovo-cel) gene therapy is an investigational one-time treatment being studied for sickle cell disease (SCD), that is designed to add functional copies of a modified form of the β-globin gene (βA-T87Q-globin gene) into a patient’s own hematopoietic (blood) stem cells (HSCs). Once patients have the βA-T87Q-globin gene, their red blood cells (RBCs) can produce anti-sickling hemoglobin (HbAT87Q) that decreases the proportion of HbS, with the goal of reducing sickled RBCs, hemolysis, and other complications. bluebird bio’s clinical development program for lovo-cel includes the completed Phase 1/2 HGB-205 and ongoing Phase 1/2 HGB-206 and Phase 3 HGB-210 studies. bluebird bio is also conducting a long-term safety and efficacy follow-up study (LTF-307) for people who have been treated with lovo-cel in bluebird bio-sponsored clinical studies.

In the BLA submission, the majority of adverse events in treated patients were attributed to underlying sickle cell disease or conditioning with busulfan. Nonserious adverse events related to lovo-cel included infusion reactions (hot flush and decreased blood pressure) in two patients (4%). Serious adverse events related to lovo-cel included anemia in two patients (4%) with alpha-thalassemia, and leukemia in two patients (4%), not resulting from insertional oncogenesis. Three of 50 patients (6%) died, one due to sudden cardiac death and two due to leukemia.

About bluebird bio, Inc.

bluebird bio is pursuing curative gene therapies to give patients and their families more bluebird days.

With a dedicated focus on severe genetic diseases, bluebird has industry-leading programs for sickle cell disease, β-thalassemia and cerebral adrenoleukodystrophy and is advancing research to apply new technologies to these and other diseases. We custom design each of our therapies to address the underlying cause of disease and have developed in-depth and effective analytical methods to understand the safety of our lentiviral vector technologies and drive the field of gene therapy forward.

Founded in 2010, bluebird has the largest and deepest ex-vivo gene therapy data set in the world—setting the standard for the industry. Today, bluebird continues to forge new paths, combining our real-world experience with a deep commitment to patient communities and a people-centric culture that attracts and grows a diverse flock of dedicated birds.

For more information, visit or follow us on social media at @bluebirdbio, LinkedIn, Instagram and YouTube.

SOURCE: bluebird bio