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Getting the latest healthcare news for you
Getting the latest healthcare news for you
The FDA has placed a clinical hold on Regenxbio's experimental gene therapy RGX-121 for Hunter syndrome after spinal scans revealed lumps or fluid-filled masses in five patients treated years earlier. The biotech says it doesn't expect to refile for approval anytime soon. Regenxbio's shares were halted in premarket trading following the announcement.
The FDA has placed a clinical hold on Regenxbio's experimental gene therapy, RGX-121, developed to treat Hunter syndrome — a rare inherited disorder that causes progressive damage to the brain and other organs. The hold was triggered after spinal scans revealed concerning abnormalities in five study participants.
The abnormalities — described as small lumps or fluid-filled masses — were detected in patients who had received the treatment approximately three to six years ago. Regenxbio acknowledged the findings and stated it does not expect to resubmit its approval application in the near term. The company's shares were halted in premarket trading following the announcement.
By the Numbers:
Why it matters: This development is a significant setback for gene therapy in rare diseases. Hunter syndrome (MPS II) has very limited treatment options, making RGX-121 a closely watched candidate. The FDA's clinical hold raises broader safety questions about long-term outcomes in gene therapy trials and could slow regulatory momentum in the space.
