- The European Commission on Wednesday approved Bluebird bio's gene therapy Skysona to treat a form of a rare and potentially deadly neurological disorder called adrenoleukodystrophy.
- The EC cleared Skysona for use in children under 18 who have cerebral adrenoleukodystrophy, a genetic disease in which fatty acids build up in the brain and trigger a harmful immune response that leads to disability and an early death. In clinical testing, Skysona helped keep most trial participants alive and free from developing major disability.
- The approval is specifically for CALD patients who have certain genetic mutations and don't have a sibling who is a match for a stem cell transplant. Bluebird hasn't yet disclosed the cost of treatment, though some Wall Street analysts project a price tag of up to $700,000 per patient.
Bluebird is an important company in gene therapy's reemergence. The company's progress developing treatments for rare genetic diseases early last decade helped boost confidence in gene therapy at a time when the field was still recovering from setbacks. Now, gene therapy is a fast-growing field, with many publicly traded companies, a handful of approved products and dozens of startups raising record levels of investment from venture investors.
But Bluebird has had a bumpy ride since debuting as a public company in 2013. Shares swung wildly over the years amid various clinical delays and manufacturing setbacks, while competition from newer gene editing technologies dimmed the outlook for some of its treatments. At less than $30 per share, Bluebird's stock currently trades at levels not recorded for eight years.
The approval of Skysona reflects Bluebird's up-and-down story. It's a scientific achievement, making Bluebird the first company with two marketed gene replacement therapies. (The company also successfully developed an genetically engineered cell therapy called Abecma for the blood cancer multiple myeloma. Others have multiple cell therapies approved.)
Skysona also represents a medical advance for patients with CALD, more than 80% of whom are estimated to not have a matched sibling donor, according to Bluebird. The gene therapy is meant to be as effective as transplants, but safer. In clinical testing, 27 of 32 patients treated with Skysona hadn't experienced major function disabilities after two years of follow up. The company also hasn't observed instances of the potentially deadly immune responses associated with transplants.
Yet Skysona isn't expected to move the needle much for Bluebird's business. CALD is rare: About 80 patients are diagnosed with the disease in the U.S. and Europe combined each year, according to SVB Leerink analyst Mani Foroohar. Identifying those patients will be a challenge for Bluebird, particularly in Europe, as the Netherlands is currently the only country in the EU that screens newborns for the disease.
"The debate around Skysona is largely focused on the market opportunity and that it's commonly perceived as only incremental," Benjamin Burnett, an analyst at Stifel, wrote in June. He predicts $120 million in peak global sales based on an assumed price of $420,000 in Europe and $700,000 in the U.S.
What's more, Bluebird has already had trouble selling its other gene therapy, the beta thalassemia treatment Zynteglo, in Europe. Difficulty convincing EU member states to cover Zynteglo's $1.8 million price tag, combined with manufacturing issues and a temporarily suspended launch, have resulted in very little use of the product.
Bluebird didn't disclose a price for Skysona. A spokesperson told BioPharma Dive via email that the company will "share additional details at a later date."
Bluebird has said it will file for U.S. approval by mid-year, though the company hasn't yet submitted an application.