“The clinical hold was initiated following the company’s submission of a serious adverse event and temporary enrollment halt to the FDA,” Sigilon said in a statement.
The stock recently traded at $6.56, down 29%, putting it 82% lower for the past six months.
“To date, three patients have been dosed with SIG-001. The third patient, who received the highest dose of study drug, developed inhibitors to Factor VIII - a well-known complication of FVIII therapy,” Sigilon said.
“The patient is responding well to medical treatment, and his condition continues to improve,” the company added.
The company said the FDA has "requested additional information or data on factors potentially contributing to the development of inhibitors in this patient."
That would include “family history and immune stimulation from a recent vaccination"