Haegarda, a C1-INH replacement medication by CSL Behring, is now available in the Canadian province of Quebec for the preventative treatment of swelling attacks in adults and adolescents with hereditary angioedema (HAE), the company announced.
“The availability of a new treatment option to help health care professionals and patients prevent HAE attacks is an important milestone and great news for the HAE patient community,” Charles St-Pierre, president of the Angio-oedème Héréditaire du Québec (AOHQ) patient group, said in a press release.
HAE is characterized by sudden and recurrent episodes of swelling in the deeper layers of the skin, the upper airways, and the gastrointestinal tract.
The disease is mostly caused by mutations in the SERPING1 gene. In HAE type 1, those mutations lead to lower levels of C1-inhibitor (C1-INH); in HAE type 2, they lead to a dysfunctional C1-INH, although its levels are either normal or elevated.
Haegarda is one of two C1-INH replacement medications approved by the U.S. Food and Drug Administration (FDA, in 2017) and by Health Canada (in 2019) for the long-term prophylactic, or preventative, treatment of adolescents and adults with HAE.
Unlike other replacement therapies that are given as into-the-vein (intravenous) injections, Haegarda is delivered as an under-the-skin (subcutaneous) injection, allowing for self-administration.
“Preventive therapy was based on intravenous administration replacement therapy of the defective serum protein. A key limitation was the IV [intravenous] route of administration. Haegarda is intended for self-administration by subcutaneous injection only,” Jacques Hebert, MD, FRCPC, director at the Centre de Recherche Appliquée en Allergies de Québec, and a research associate at the Laval University, Québec, said in the release.
Haegarda’s approvals were based on findings — published in 2019 — from the COMPACT Phase 3 trial (NCT01912456). Trial results showed that the treatment lowered the frequency of HAE attacks by a median of 95% when used at a dose of 60 IU/kg twice weekly. People on the treatment also largely had no need of rescue medications (a median reduction of 100%).
The double-blind, placebo-controlled trial included 90 patients with HAE type 1 and 2, ages 12 or older, who were randomly assigned to one of four treatment groups: placebo followed by Haegarda at 40 IU/kg or 60 IU/kg; or Haegarda 60 IU/kg or 40 IU/kg, followed by placebo.
All were treated twice-a-week via an under-the-skin injection, given over two, 16-week periods.
People on the 40 IU dose had 2.4 fewer monthly swelling attacks than those given a placebo, and those in the 60 IU dose had 3.5 fewer monthly attack.
During the Haegarda treatment, 43% of patients in the 40 IU dose and 58% in the 60 IU dose experienced a 90% or greater reduction in monthly swelling attacks, compared to the 16 weeks they were given placebo. Patients on the treatment were more often free of attacks.
Both doses of Haegarda were reported to be well-tolerated by patients. The most common side effects observed during the trial were mild injection-site reactions; these were seen in a similar number of people treated with Haegarda versus a placebo.
CSL Behring Canada has an assistance program, called Haegarda Connect, to aid patients in learning how best to self-administer Haegarda, as well as educational materials. Patients need to ask their healthcare professionals to join the program.