Bluebird bio's Neurodegenerative Disease Gene Therapy Under Priority FDA Review, Despite Clinical Hold

The FDA has accepted for priority review Buebird bio Inc's BLUE marketing application for elivaldogene autotemcel (eli-cel, Lenti-D) for cerebral adrenoleukodystrophy (CALD) in patients less than 18 years of age. 

• The agency set a Prescription Drug User Fee Act (PDUFA) goal date of June 17, 2022.
• If approved, eli-cel will be the first approved treatment to address the underlying genetic cause of CALD in the U.S. 
• The submission is supported by efficacy and safety data from the completed Phase 2/3 Starbeam study (ALD-102) (N=32). 
• In ALD-102, 90.6% (29/32) of patients met the primary endpoint of Major Functional Disabilities (MFD)-free survival at 24 months. 
• Additionally, the application contains data for 23 subjects dosed in Phase 3 ALD-104 study. Study ALD-104 has subsequently completed enrollment, and follow-up is ongoing.
• In August, the FDA placed eli-cel clinical program on clinical hold following a Suspected Unexpected Serious Adverse Reaction (SUSAR) of myelodysplastic syndrome (MDS). 
• Available evidence suggests that the event was likely mediated by Lenti‑D lentiviral vector insertion. Consistent with this known risk, two additional cases of MDS have subsequently been reported. The FDA clinical hold for eli-cel is ongoing. 
• Adrenoleukodystrophy is caused by mutations in the ABCD1 gene that affect the production of adrenoleukodystrophy protein (ALDP) and subsequently lead to toxic accumulation of very long-chain fatty acids, primarily in the adrenal gland and white matter of the brain and spinal cord. 
• Price Action: BLUE shares are down 0.75% at $10.54 during the premarket session on the last check Monday.