KalVista Pharmaceuticals presented new data at the American College of Allergy Asthma and Immunology (ACAAI) demonstrating the potential of sebetralstat, an oral plasma kallikrein inhibitor, for the on-demand treatment of hereditary angioedema (HAE). The Phase 3 KONFIDENT trial indicated that earlier treatment with sebetralstat resulted in faster resolution of HAE attacks.
Faster Resolution with Early Intervention
Tim Craig, DO, of Penn State Health, emphasized that complete attack resolution was achieved more quickly when treatment was initiated sooner. Data from the Phase 3 trial revealed that attacks treated in the earliest phase (1st quartile) resolved faster than those treated later (4th quartile), supporting the clinical value of early treatment for HAE attacks, which can be life-threatening due to tissue swelling in various parts of the body.
Significant Symptom Reduction
William Lumry, MD, from the AARA Research Center in Dallas, presented data indicating that sebetralstat significantly reduced symptom burden compared to placebo. In attacks that had reached at least moderate severity before treatment, sebetralstat led to a median time of symptom relief of approximately 5 hours, compared to over 12 hours with placebo.
Comparison with Existing Treatments
The data also included an indirect comparison between oral sebetralstat and intravenous recombinant C1-inhibitor (IV rhC1-INH), showing no significant differences in the time to the beginning of symptom relief. Furthermore, a pooled analysis from the KONFIDENT and KONFIDENT-S trials found that sebetralstat effectively treated laryngeal HAE attacks, with median times to beginning of symptom relief and to complete attack resolution being 1.5 and 9.7 hours, respectively.
Addressing Unmet Needs
The presentations highlighted the challenges HAE patients face with current on-demand treatments, which require intravenous or subcutaneous administration, often leading to delays due to the invasiveness of the methods. Sebetralstat, if approved, could offer a less invasive and more accessible treatment option.
Regulatory Status and Future Prospects
Sebetralstat has received Fast Track and Orphan Drug Designations from the U.S. FDA and is currently under regulatory review with a Prescription Drug User Fee Act (PDUFA) goal date of June 17, 2025. KalVista has also submitted marketing authorization applications for sebetralstat in several other regions, including the European Union and the United Kingdom. KalVista has also submitted Marketing Authorization Applications for sebetralstat to regulatory authorities in the United Kingdom, Switzerland, Australia, and Singapore.
