KalVista Pharmaceuticals said that the Phase 3 KONFIDENT clinical trial of sebetralstat as oral on-demand therapy for hereditary angioedema (HAE) has yielded positive results by meeting all the primary and key secondary endpoints.

The KONFIDENT trial also revealed a favourable safety profile for the oral plasma kallikrein inhibitor.

The randomised, double-blind, event-driven, crossover clinical trial assessed the efficacy and safety of sebetralstat 300mg and 600mg versus placebo for on-demand treatment of HAE.

It recruited 136 adult and adolescent HAE patients from 66 clinical sites across 20 countries, making it the largest clinical trial conducted in HAE to date. Participants included type 1 and type 2 HAE patients who had experienced at least two attacks in the 90 days prior to enrolment.

Attacks treated with both 300mg and 600mg of the oral plasma kallikrein inhibitor achieved the primary endpoint of symptom relief significantly faster than placebo, with median times to symptom relief of 1.61 hours and 1.79 hours for the respective doses, compared to 6.72 hours for placebo.

Key secondary endpoints also showed that attacks treated with the drug candidate achieved a significantly faster reduction in attack severity from baseline compared to placebo.

Moreover, attacks treated with sebetralstat demonstrated a significantly faster complete resolution compared to placebo.

KalVista Pharmaceuticals CEO Andrew Crockett said: “We are thrilled to announce positive phase 3 results for the KONFIDENT trial, which we believe position sebetralstat to become the first oral, on-demand therapy for the treatment of HAE.

“These clinically meaningful results represent a potentially significant advance for people living with HAE. If approved, sebetralstat may offer a compelling treatment option for patients and their caregivers given the long-standing preference for an effective and safe oral therapy that provides rapid symptom relief for HAE attacks.”

Sebetralstat had received fast track and orphan drug designations from the US Food and Drug Administration (FDA), as well as orphan drug designation and an approved paediatric investigational plan from the European Medicines Agency (EMA).