US regulators have approved CSL Behring’s Haegarda, the first C1 esterase inhibitor for subcutaneous administration to prevent hereditary angioedema (HAE) attacks in adolescent and adults.

HAE is a rare genetic disease caused by having insufficient amounts of a plasma protein called C1-esterase inhibitor (or C1-INH), affecting around 6,000 to 10,000 people in the US.

The condition causes painful, debilitating, and unpredictable episodes of swelling of the hands, feet, limbs, face, intestinal tract or airway, which can occur spontaneously, or can be triggered by stress, surgery or infection.

Haegarda is a human plasma-derived, purified, pasteurised, freeze-dried concentrate prepared from large pools of human plasma from US donors.

In trials, the therapy reduced the median rate of HAE attacks by 95 percent relative to placebo at the approved dose and the need for rescue medication by more than 99 percent.

The subcutaneous route of administration also allows for easier at-home self-injection by the patient or caregiver, once proper training is received, the regulator noted.