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# FDA Questions Safety/Efficacy of Bluebird’s Eli-Cel
- URL: https://www.fdaweb.com/fda-questions-safety-efficacy-of-bluebirds-eli-cel/
- Published: 2022-06-07T12:00:00.000Z
- Updated: 2026-09-14T17:47:35.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5151999

FDA says it is challenged to determine the overall benefit-risk profile of Bluebird bio’s eli-cel (elivaldogene autotemcel) gene therapy, indicated for treating patients less than 18 years of age with early cerebral adrenoleukodystrophy who do not have an available and willing human leukocyte antigen-matched sibling hematopoietic stem cell donor. In an advisory committee [briefing document](https://www.fda.gov/media/159010/download?ref=fdaweb.com) released in advance of a 6/9 panel meeting to review the therapy, FDA says the benefit-to-risk ratio is “difficult to characterize because of the uncertain benefit and the uncertain magnitude of the risk of MDS” \[myelodysplastic syndrome\], a life-threatening malignancy which occurred in three subjects. 

The advisory committee will be asked to discuss whether the efficacy data support the presence of a clinically meaningful benefit related to eli-cel, and, if so, in what population. Additionally, panel members will be asked to discuss whether there should be increased concerns about MDS occurrence in eli-cel because of similar events seen in the company’s related product, lovo-cel, for treating sickle cell disease, which was placed on clinical hold by FDA.