Bluebird bio is facing a one-year delay in its plans to seek approval of LentiGlobin for sickle cell disease as it works to satisfy newly raised concerns from the Food and Drug Administration about manufacturing of the gene therapy.
After consulting with agency officials, Bluebird agreed to requests to demonstrate the product it’s using in clinical trials is comparable to what will be given to patients commercially. The extra work, along with delays caused by the COVID-19 pandemic, means the company won’t be able to submit its therapy for FDA approval until late 2022, instead of the second half of 2021.
The longer timeline, which comes after a series of manufacturing-related setbacks for Bluebird, sparked a 16% drop in the company’s stock, with shares falling to about $49 apiece in early trading Thursday. Delays could enable rival programs, such as a gene editing treatment from Vertex and CRISPR Therapeutics, to gain ground.
After years of ups and downs, gene therapy finally broke through in the U.S. in 2018 with the approval of Luxturna, an eye disease treatment. A second approval, for the spinal muscular atrophy treatment Zolgensma, quickly followed, portending what looked to be a spike of additional rulings to come.
But as the next crop of gene therapies move closer to approval, more have run into problems getting to the finish line. Several gene therapies have faced increased scrutiny from the FDA over the complex, multi-step processes required to make them, and to ensure that the treatments manufactured at scale are just as good as what’s being tested in clinical trials. This has led to delays for several programs.
Last month, for example, the agency demanded more information on manufacturing processes before allowing Voyager Therapeutics to begin tests in humans of an experimental gene therapy for Huntington’s disease. Iovance Biotherapeutics and Sarepta are also facing potential delays over FDA requests for additional lab tests to better assess their experimental therapies.
Meanwhile, Axovant Gene Therapies pushed back enrollment of its planned Phase 2 study in Parkinson’s disease to 2022 because its manufacturing partner, Oxford Biomedica, said it’s having trouble generating manufacturing data on time.
The setback for Bluebird’s LentiGlobin in sickle cell disease is “frustrating”, SVB Leerink analyst Mani Foroohar wrote in a note to investors, because Bluebird has made significant investments in manufacturing and process development. Foroohar still has a positive view of Bluebird’s portfolio, but now wonders if the company needs a larger, more experienced partner.
The assets might be “best realized by an organization with the robust infrastructure of a large-cap biopharma company,” he wrote.
The latest news comes after a series of disappointments for Bluebird. The company had already pushed back its plan to seek approval of LentiGlobin for beta-thalassemia until mid-2021 after failing to reach an agreement with the FDA on the need for additional data. Bluebird also faced delays in treating its first commercial patient in Europe with the therapy, where it’s approved as Zynteglo.
In announcing the revised timeline in sickle cell disease, Bluebird said the new plan reached with the FDA will “meaningfully de-risk” the program going forward.
But the news also enables rival programs to catch up. A gene editing treatment under development by Vertex and CRISPR Therapeutics, which just produced its latest results this week, continues to show promise. Others from Intellia Therapeutics and Novartis, as well as Sanofi and Sangamo, are also advancing.