FDA Approves Subcutaneous C1 Esterase Inhibitor to Treat Rare Genetic Disease

The U.S. Food and Drug Administration approved Haegarda, the first C1 Esterase Inhibitor for subcutaneous administration to prevent Hereditary Angioedema (HAE) attacks in adolescent and adult patients. The subcutaneous route of administration allows for easier at-home self-injection by the patient or caregiver, once proper training is received.

HAE, which is caused by having insufficient amounts of a plasma protein called C1-esterase inhibitor (or C1-INH), affects approximately 6,000 to 10,000 people in the U.S. People with HAE can develop rapid swelling of the hands, feet, limbs, face, intestinal tract or airway. These attacks of swelling can occur spontaneously, or can be triggered by stress, surgery or infection.

"The approval of Haegarda provides a new treatment option for adolescents and adults with Hereditary Angioedema," said Peter Marks, M.D., Ph.D., director of FDA's Center for Biologics Evaluation and Research. "The subcutaneous formulation allows patients to administer the product at home to help prevent attacks."

Haegarda is a human plasma-derived, purified, pasteurized, lyophilized concentrate prepared from large pools of human plasma from U.S. donors. Haegarda is indicated for routine prophylaxis to prevent HAE attacks, but is not indicated for treatment of acute HAE attacks.

The efficacy of Haegarda was demonstrated in a multicenter controlled clinical trial. The study included 90 subjects ranging in age from 12 to 72 years old with symptomatic HAE. Subjects were randomized to receive twice per week subcutaneous doses of either 40 IU/kg or 60 IU/kg, and the treatment effect was compared to a placebo treatment period. During the 16‑week treatment period, patients in both treatment groups experienced a significantly reduced number of HAE attacks compared to their placebo treatment period.

The most common side effects included injection site reactions, hypersensitivity (allergic) reactions, nasopharyngitis (swelling of the nasal passages and throat) and dizziness. Haegarda should not be used in individuals who have experienced life-threatening hypersensitivity reactions, including anaphylaxis, to a C1-INH preparation or its inactive ingredients.\

Haegarda received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs to treat rare diseases or conditions.