Bluebird Bio Delays Application Submission for Approval of Sickle Cell Gene Therapy

Rare Daily Staff

Gene therapy focused biotech Bluebird Bio said it would not meet its anticipated first quarter 2023 goal for filing a Biologics License Application for lovo-cel for sickle cell disease, sending its shares down 30 percent.

The news was reported in Bluebird’s financial results and business highlights for the fourth quarter and full year ended December 31, 2022, which also highlighted the commercial progress of Bluebird’s two gene therapy approvals to Bluebird in 2022: Zynteglo for beta thalassemia and Skysona for cerebral adrenoleukodystrophy (CALD).

In early March, the company responded to feedback from the FDA on vector and drug product analytical comparability evaluations completed in December 2022 and expects a response from the FDA within a matter of weeks. Bluebird says it will move quickly to expedite its BLA submission, pending alignment with FDA on product comparability.

“We also remain laser focused on our lovo-cel BLA for sickle cell disease,” said Andrew Obenshain, CEO of Bluebird Bio. “Lovo-cel is the most deeply studied gene therapy in development for sickle cell disease, with more than 50 patients treated and multiple patients followed for more than six years. We remain extremely confident in the quality of our BLA submission. Most importantly, we know that patients and their families are waiting, and we will move quickly to expedite our BLA submission, pending alignment with FDA on product comparability.”

The company plans to request priority review for patients 12 and older with a history of vaso-occlusive events. If approved, Bluebird continues to anticipate a commercial launch in early 2024.

People with sickle cell disease (SCD) have a mutation that alters hemoglobin, the protein in red blood cells that carries oxygen to cells throughout the body. The sickle mutation causes red blood cells to have an abnormal sickle or crescent shape, which makes them inefficient in their oxygen-carrying capacity and leads to chronic anemia, vaso-occlusive crises with severe pain, multi-organ damage, complications like stroke, and a shortened life expectancy. Globally, 300,000 people are born with sickle cell disease every year, and approximately 100,000 people are living with sickle cell disease in the United States.

Lovo-cel (lovotibeglogene autotemcel) gene therapy is an investigational one-time treatment being studied for sickle cell disease 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.

Photo: Andrew Obenshain, CEO of Bluebird Bio