- A committee that advises Europe's drug regulator is recommending that a gene therapy developed by Bluebird bio for a rare, often deadly disease be approved for market.
- The disease, known as adrenoleukodystrophy or ALD for short, is caused by genetic mutations that lead to a toxic buildup of molecules in the brain and spinal cord. In clinical testing, Bluebird's therapy, now called Skysona, has shown positive effects on cerebral ALD — the most common and severe form of the disease — with the vast majority of treated patients staying alive and free of major functional disabilities.
- The European Medicines Agency is now advising the European Commission to authorize Skysona for the treatment of early cerebral ALD in children with certain genetic mutations who don't have a sibling that can be a match for hematopoietic stem cell donation. Bluebird says a final decision is expected in mid-2021.
A Skysona approval could help prop up Bluebird after what's been a challenging year for the Cambridge, Massachusetts-based drugmaker.
In February, the company stopped two clinical trials that were testing one of its other gene therapies, called LentiGlobin, after one participant developed blood cancer and another a disease of the bone marrow. Though Bluebird has since concluded these cases were "very unlikely" to be related to the therapy, the news still placed major concerns over its business, and its stock price remains significantly lower than early in the year.
Those safety scares also came on the heels of Bluebird disclosing that its plans to seek approval for LentiGlobin in the U.S. would be delayed by a year, as the Food and Drug Administration wanted more information about how the therapy is manufactured.
Additionally, Bluebird is in the midst of a major reorganization, announcing in January that it will split in two, with its cancer drug business spun out into an independent, publicly traded company. The biotech is looking for a new top doctor, too, as its longtime chief medical officer David Davidson departed this spring.
Amid all those moving parts, Skysona could provide a helpful source of income for Bluebird, provided it secures approval. Though Bluebird has two marketed products in Zynteglo, a gene therapy sold in Europe for the blood disorder beta-thalassemia, and Abecma, a treatment for multiple myeloma recently cleared by the FDA, it still doesn't generate material revenue from either. The company ended the first quarter with a net loss of $206 million.
With ALD, estimates hold that one in every 21,000 male newborns are affected, and approximately 40% of those cases are the severe, cerebral type.
Bluebird believes Skysona could be a valuable treatment option for these boys, especially following results from a small clinical study named Starbeam. The study enrolled 32 participants and, as of the latest data cutoff, 27 of them had made it two years post treatment without major function disabilities. Notably, two participants left the study early because investigators feared they weren't responding to treatment, while another participant died after experiencing rapid disease progression.
Starbeam provided the evidence needed for the EMA to recommend approval. Now, the attention turns to the European Commission.
"There is an urgent need for treatment options," said Guy Alba, president of the European Leukodystrophies Association, in a Friday statement from Bluebird. "We support all initiatives that, like gene therapy, could change the lives of patients. This milestone is a very important step forward in options for the care of patients with CALD."
An approval from the European Commission wouldn't be the last obstacle in Bluebird's path, however.
In its statement, the company noted how, once patients have been diagnosed with ALD, regular MRI scans are needed to determine whether they're progressing to the cerebral form. But, with the exception of the Netherlands, countries in the European Union don't screen newborns for early ALD, according to Bluebird. It is therefore "difficult to detect patients at risk of developing CALD."