Regenxbio said the FDA has placed a clinical hold on RGX-121, its investigational gene therapy for mucopolysaccharidosis type II, after spine MRI abnormalities were found in five participants in the CAMPSIITE study.
The company said the five findings were asymptomatic and identified through an expanded MRI monitoring plan. The abnormalities were described as either a small nodule or a small cystic mass in the spine of participants who received intracisternal or intraventricular RGX-121 about three to six years ago. Regenxbio said investigators deemed the findings nonserious and radiologists believe they are likely benign. No brain nodules or masses were found on any brain MRIs.
All five participants remain clinically stable, with overall stability to improvement on neurocognitive and neurobehavioral assessments.
Regenxbio said it does not expect to resubmit the RGX-121 biologics license application in the near term. The company and partner NS Pharma are evaluating additional imaging and longer-term follow-up data and will incorporate FDA feedback once the full clinical hold letter is received.
The update comes as Regenxbio pointed to other programs as near-term priorities. The company said it remains focused on its Duchenne and retinal disease candidates, with a planned Duchenne BLA submission due this quarter and topline pivotal data for wet AMD expected in the fourth quarter.
RGX-121 is being developed for boys with MPS II, also known as Hunter syndrome. About 2,000 patients worldwide are diagnosed with the disease, and more than 500 babies are born with it each year. Today the company's shares have moved 7.38% to a price of $8.6499. For more information, read the company's full 8-K submission here.
