The highest-profile symptoms of Parkinson’s disease (PD) are well known. But for many PD patients, there is a lesser-known but equally important symptom that affects their well-being: “freezing” or “off” episodes that are marked by acute immobility, occur between one and six times daily, and last from one to several hours. These episodes may be triggered when mainstream treatments such as levodopa or enzyme inhibitors are too slow in entering the bloodstream.
An acute rescue therapy exists to treat these “off” periods when they occur: apomorphine, the only drug approved (under the name APOKYN® in the U.S. and Japan and APO-go® in Europe and parts of Asia) to treat this symptom. Unfortunately, apomorphine is primarily available in an inconvenient and painful injectable form (as well as, in Europe, as an abdominal infusion pump)—problematic not only because it needs to be administered up to six times a day, but because the injection can produce painful reactions including irritation and nodules at the injection site on the body, since apomorphine is only stable in a highly acidic formulation.