FDA Places Clinical Hold On Sigilon's Phase 1/2 Study In Hemophilia A; Stock Plunges

(RTTNews) - The U.S. Food and Drug Administration has placed clinical hold on Sigilon Therapeutics Inc.'s (SGTX) phase 1/2 study of SIG-001 in patients with severe or moderately severe hemophilia A. The clinical hold was initiated following the company's submission of a serious adverse event and temporary enrollment halt to the FDA and other regulatory agencies.

In Friday pre-market trade, SGTX was trading at $7.20 down $2.04 or 22.08%.

The company said it is conducting a thorough investigation of the event to confirm whether there was a causal relationship between the development of inhibitors and SIG-001. It is committed to working with the FDA to resolve the clinical hold.

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 (FVIII) — a well-known complication of FVIII therapy. The patient is responding well to medical treatment and his condition continues to improve, Sigilon said in a statement.

The FDA has requested additional information or data on factors potentially contributing to the development of inhibitors in this patient, such as family history and immune stimulation from a recent vaccination. All three patients enrolled in this study will continue to be followed per study protocol, while the company investigates the serious adverse event.