Bluebird's lovo-cel flies closer to approval as FDA rules out advisory committee meeting

The path to potential approval for bluebird bio’s lovo-cel has become slightly smoother as the FDA has confirmed it will not be holding an advisory committee meeting before making a decision on the sickle cell disease (SCD) gene therapy in December.

Bluebird submitted the application for lovotibeglogene autotemcel (lovo-cel) in April, backed by efficacy results from 36 patients with 32 months of follow-up data and two patients with 18 months follow-up. The filing also included safety data from 50 patients, including six patients with six or more years of follow-up. This is the longest follow-up of any gene therapy program for SCD, the biotech pointed out in this morning’s release.

“Lovo-cel is the most deeply studied gene therapy in development for sickle cell disease and represents the third lentiviral vector gene therapy that the agency has reviewed from bluebird—giving us great confidence in the robustness and maturity of our BLA package,” said CEO Andrew Obenshain. “We remain focused on working with the agency on its review in anticipation of a decision by the end of this year.”

Lovo-cel hit some speed humps earlier in its clinical journey, including a partial clinical hold in late 2021 after one case of “persistent, nontransfusion-dependent anemia” in an adolescent patient. Before that, the program suffered a delay of around a year after the FDA requested “an analytical comparability strategy” from the company to reassure the regulator that the final product wouldn’t differ from clinical supplies.

Now, all eyes are on the FDA’s decision date of December 20. If the decision goes bluebird’s way, it would mark the company's third approval for an ex-vivo gene therapy from the regulator. Those therapies—Zynteglo for beta thalassemia and Skysona for cerebral adrenoleukodystrophy—aced advisory committee votes in a two-day meeting back in June 2022.

Since their approvals in August and September of that year, Zynteglo has signed on 11 beta-thalassemia patients and Skysona five patients in the rare brain disease cerebral adrenoleukodystrophy, bluebird revealed last week.

Bluebird set out plans last week to activate around 40 to 50 treatment centers for Zynteglo by the end of the year, but there’s still a lot riding on the lovo-cel approval. Ever since the company initiated a major restructuring in spring 2022, the biotech has been warning of “substantial doubt” about its ability to survive in the near term. For now, bluebird expects its cash runway to extend into late 2024.

What’s more, if lovo-cel gets the green light, it’s likely to go head-to-head with Vertex and CRISPR Therapeutics’ CRISPR-based exa-cel in SCD. The rival drug is due to get an FDA decision just weeks earlier than lovo-cel—on Dec. 8.