Experimental Treatments for Angioedema

There are a number of experimental treatments for angioedema that are currently in various developmental stages and not yet approved by the U.S. Food and Drug Administration (FDA) or medical regulators in other countries.


SHP616 is a candidate medication for late-stage hereditary angioedema (HAE) being developed by biopharmaceutical company Shire. SH616 is a C1 esterase inhibitor given as an injection under the skin. It is intended to increase the body’s levels of C1 inhibitor protein to prevent angioedema attacks in HAE patients. A recent Phase 3 clinical trial (NCT02584959) showed that HAE patients receiving SH616 treatment had a significant reduction in the number of angioedema attacks per month.


ATN-249 is a potential HAE medication in development by Attune Pharmaceuticals. It is a kallikrein inhibitor taken orally. Kallikrein is a member of a complex network of blood proteins that direct the inflammatory process in the body. In March 2017, Attune announced that the results of pre-clinical studies were promising, but clinical trials have not yet begun.


KVD824 is also an oral kallikrein inhibitor being developed to prevent HAE attacks by KalVista Pharmaceuticals. Early clinical trials in healthy participants were promising and KalVista announced that they would be filing an Investigational New Drug (IND) application with the FDA in order to start a Phase 2 clinical trial in 2021.


KalVista Pharmaceuticals is also developing another oral kallikrein inhibitor called KVD900. KVD900 is currently finishing up a Phase 2 clinical trial in 68 patients with type I and type 2 HAE in the U.S. and Europe. Based on the results of the trial, KalVista may file a New Drug Application (NDA) with the FDA in 2021.


PHA121 is an investigational treatment for HAE being developed by Pharvaris. PHA121 is an inhibitor of the bradykinin B2 receptor that blocks bradykinin from activating the receptor. PHA121 will soon be investigated in a Phase 2 trial called RAPIDe-1 (NCT04618211) which will recruit an estimated 54 patients with type 1 or type 2 HAE in order to investigate the treatment’s effects on skin swelling, skin pain, and abdominal pain during HAE attacks.

Tranexamic acid

Tranexamic acid is an oral antifibrinolytic medication that is sometimes used to treat HAE or idiopathic non-histaminergic angioedema. It may be useful as a maintenance treatment to prevent angioedema attacks because it is inexpensive and generally well-tolerated.


Omalizumab is a monoclonal antibody that reduces sensitivity to allergens. It is being investigated as a treatment for idiopathic angioedema. “Idiopathic” means that doctors cannot determine the cause of the condition. A Phase 4 clinical trial (NCT02966314) is currently recruiting participants in Wisconsin to evaluate omalizumab as an add-on therapy for idiopathic angioedema. Participants must be 18 years of age or older, and must have had at least two angioedema attacks in the past six months despite other treatments.

Fresh frozen plasma

Fresh frozen plasma (FFP) has been used “off-label” to treat progressive cases of ACE inhibitor-induced angioedema when no other approaches work. Some case studies have shown that FFP can successfully treat patients in whom ACE inhibitor-induced angioedema has become life-threatening (i.e., when swelling is obstructing airways). FFP is also sometimes used to treat acute attacks in patients with HAE.

Gene therapy

Researchers led by Odelya Edith Pagovich, MD, of the Weill Medical College of Cornell University are working on a gene therapy treatment that would allow HAE patients to produce functional C1 inhibitor protein, which could prevent angioedema attacks. This research is in its early stages.


Angioedema News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.