• The committee that advises European regulators on whether or not to approve pharmaceuticals has put its support behind an experimental gene therapy developed by Bluebird bio.
• Should the European Commission follow that recommendation, it would clear Bluebird’s Zynteglo (until recently called LentiGlobin) for patients aged 12 years and older with a less severe form of a blood disorder called transfusion-dependent beta-thalassemia. The patients must also meet certain other criteria.
• The EU typically follows the advice of the European Medicines Agency committee, and Bluebird expects an approval decision before the end of June. Across the pond, the biotech plans to file its gene therapy with U.S. regulators sometime this year. Despite that progress, significant commercialization and manufacturing hurdles inherent to gene therapy remain ahead.

An approval of Zynteglo would be more validating than revenue-driving for Bluebird and its technology platform, at least for the next few years.

“Overall, the approval of lentiglobin will mark the first approval for the bluebird platform, and will help de-risk the regulatory outlook for complex adoptive cellular therapies,” Dane Leone, an analyst at Raymond James, wrote in a March 29 note.

Leone foresees Zynteglo securing approvals from the EU in 2019 and the Food and Drug Administration in 2020. He estimates Zynteglo will rack up $5 million this year and $58 million next year — modest sales reflecting the “considerable time and effort” required for Bluebird to establish pricing and reimbursement deals in European countries.

The European marketing application for Zynteglo doesn’t include patients who have a genotype reflective of a more severe form of beta-thalassemia. That subset, however, is the one Wall Street expects to be the biggest market opportunity for Bluebird’s therapy​ in beta-thalassemia​.

The biotech is looking at these more severe patients in a Phase 3 trial.

Early data from the trial, dubbed Northstar-3, were presented along with two other Zynteglo studies in November at the American Society of Hematology’s annual meeting. Although the studies scored positive efficacy results, they were also somewhat dogged by one case where a Zynteglo-treated patient developed myelodysplasia syndrome, a cancer-like bone marrow disease.

Updated results from Northstar-3 are expected to come at the end of this year.

As gene therapies have transformed from a lofty science to a realized commercial opportunity, drug companies and payers have advanced conversations about reimbursement and coverage. With only one gene therapy for an inherited disease on the market, though, challenges remain.

Amid those headwinds, Raymond James models Zynteglo achieving just about 2%, or around 900 patients per year, of the estimated total beta-thalassemia population in Europe by 2027.

Zynteglo should be a boon for Bluebird over the long-term, however. SVB Leerink anticipates that by 2030, peak worldwide sales of the therapy will reach $1.2 billion for the transfusion-dependent beta-thalassemia indication.

“The burden placed on these patients and their families is significant. It extends beyond immediate health implications to their daily lives, which are affected by the symptoms, hospitalizations and necessary chronic care required,” said Franco Locatelli, professor of pediatrics at the Sapienza University of Rome, said in a statement from Bluebird.