KalVista Pharmaceuticals has achieved a significant milestone with sebetralstat, a novel, investigational oral plasma kallikrein inhibitor, receiving Orphan Drug Designation from Japan’s Ministry of Health, Labour and Welfare (MHLW). Concurrently, the company has submitted a New Drug Application (NDA) to the MHLW, seeking approval for sebetralstat as an on-demand treatment for hereditary angioedema (HAE) attacks in adults and adolescents aged 12 years and older.
Potential Impact on HAE Treatment in Japan
If approved, sebetralstat would be the first oral on-demand treatment available for HAE patients in Japan. This represents a significant advancement, as current treatment options may not be as convenient or accessible for all patients. Ben Palleiko, CEO of KalVista, emphasized the importance of this step, stating that the NDA submission is a key move in making this new treatment available to as many people living with HAE as possible.
The Orphan Drug Designation acknowledges the critical need for new, effective treatments for HAE in Japan and highlights sebetralstat's potential to provide meaningful relief for patients who have faced ongoing challenges with existing options.
Clinical Trial Data Supporting NDA Submission
The NDA submission is supported by data from the KONFIDENT Phase 3 clinical trial and the KONFIDENT-S open-label extension trial. The KONFIDENT trial was a randomized, double-blind, three-way crossover study that evaluated the safety and efficacy of sebetralstat 300 mg and 600 mg versus placebo for the on-demand treatment of HAE in adult and pediatric patients aged 12 years and older. The trial randomized 136 HAE patients from 66 clinical sites across 20 countries.
Participants in the KONFIDENT trial treated each eligible attack with up to two doses of the study drug and treated up to three attacks over the course of the study. The trial included type 1 and type 2 HAE patients who had experienced at least two documented HAE attacks within 90 days prior to randomization and also included patients receiving long-term prophylaxis.
KONFIDENT-S is an open-label extension trial evaluating the long-term safety and efficacy of sebetralstat for the on-demand treatment of HAE attacks in adults and pediatric patients aged 12 years and older with HAE Type I or Type II. KalVista is transitioning ongoing participants in the trial to a novel oral disintegrating tablet (ODT) formulation to support a planned 2026 sNDA filing. If approved, the ODT formulation would provide people living with HAE with an alternative, novel option for oral, on-demand treatment.
