According to claims data, there are an estimated 37,000 diagnosed IH patients in the United States, although the total patient population may be greater due to some patients who have not yet been diagnosed, have been misdiagnosed, or are not currently seeking treatment. About Avadel Pharmaceuticals plc Avadel Pharmaceuticals plc (Nasdaq: AVDL) is a biopharmaceutical company focused on transforming medicines to transform lives. Our approach includes applying innovative solutions to the development of medications that address the challenges patients face with current treatment options.