Both Vertex Pharmaceuticals Inc.’s Casgevy (exagamglogene autotemcel, exa-cel) and Bluebird Bio Inc.’s Lyfgenia (lovotibeglogene autotemcel, lovo-cel) received U.S. FDA approval Dec. 8, providing 16,000 American sickle cell patients who have recurring vaso-occlusive events with access to the first cell-based gene therapies.

With a landmark U.K. approval in hand for Casgevy (exagamglogene autotemcel [exa-cel]) to treat sickle cell disease and transfusion-dependent beta thalassemia, Crispr Therapeutics AG and partner Vertex Therapeutics Inc. are turning their attention to the PDUFA dates set by the U.S. FDA for the treatment in both conditions.

Had it been asked to, the FDA’s Cellular, Tissue and Gene Therapies Advisory Committee would have voted Oct. 31 to recommend approval of Vertex Pharmaceutical Inc. and Crispr Therapeutics AG’s exagamglogene autotemcel, or exa-cel, as a one-time transformative treatment for severe sickle cell disease in individuals 12 and older.

It’s just a discussion next week of Vertex Pharmaceuticals Inc. and Crispr Therapeutics AG’s sickle cell disease (SCD) therapy, with no vote expected from the U.S. FDA’s Cellular, Tissue and Gene Therapies Advisory Committee. The FDA isn’t questioning the drug’s efficacy as much as it is concerned about the effects of off-target editing.