According to a media report, the US Food and Drug Administration's (FDA) staff reviewers have urged the agency's advisory panel to consider the necessity of additional studies for the sickle cell disease gene therapy developed by Vertex Pharmaceuticals and CRISPR Therapeutics. The therapy, known as exagamglogene autotemcel or exa-cel, utilises innovative CRISPR gene-editing technology and marks the first of its kind to reach the FDA for potential approval, the report in the media stated.
Reportedly, the FDA's reviewers have expressed concerns about the potential for "off-target" unintended genomic alterations resulting from this gene-editing approach, which could lead to other side effects. While they did not raise concerns about the therapy itself, they did note that the genetic sample size used in the therapy's lab analysis may be insufficient for a comprehensive safety assessment, as it fails to represent the full diversity of the US population affected by sickle cell disease, the report added. The adequacy of the company's analysis in assessing the off-target risk is also in question.
As per a report in the media, RBC analyst Luca Issi suggested that the FDA's concerns appear to be manageable and anticipates additional studies may be required post-approval.
Vertex and CRISPR therapeutics are seeking FDA approval for this therapy designed to treat the inherited red-blood-cell disorder responsible for abnormally shaped cells due to haemoglobin level irregularities, the report said.
The report further informed that an independent panel is scheduled to convene to discuss the off-target analysis and the potential need for additional laboratory studies. The FDA is expected to make a decision regarding the therapy's use in patients aged 12 years and older by December 8.
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