AM IMPAKT - New clinical trial investigates apomorphine injection for resolving debilitating morning akinesia in Parkinson's disease patients

AM IMPAKT, short for Apokyn for Motor IMProvement of Morning AKinesia Trial, is a Phase IV, multi-center,  open-label study investigating treatment with APOKYN (APO-go/Apomine) injection to achieve rapid and reliable improvement  of motor symptoms in Parkinson’s disease (PD) patients who experience delayed  onset of their oral levodopa medication taken upon awakening. A sub-study will  also investigate how gastrointestinal (GI) symptoms, commonly experienced by PD  patients, may contribute to this delayed onset of effect.

PD patients experience motor  fluctuations resulting from the brain’s decreasing ability to maintain a  consistent level of dopamine.  The states  of motor function in PD patients are referred to as ‘ON’ and ‘OFF,’ and most  patients are on a treatment regimen designed to limit the amount of ‘OFF‘ time  they experience with medicines such as levodopa that impact dopamine  production.  Up to half of all patients  receiving levodopa can develop symptoms of ‘wearing off’ within 2 years of  starting levodopa therapy3.   Also, impaired motor function can often occur in PD patients as a result  of unreliable onset of therapeutic effect after taking a dose of oral  medication; this is referred to as ‘delayed ON’ and when it occurs upon  awakening is referred to as ‘morning akinesia’. Symptoms of morning akinesia  include slowness, stiffness, freezing and falls, and can have a significant  impact on the subject’s ability to carry out their normal daily morning  activities.

Some degree of GI dysfunction is  common in PD patients as part of the disease process, including gastroparesis,  where the stomach takes longer than normal to empty. Gastroparesis is common in  both early and advanced PD; in fact it has been suggested that delayed gastric  emptying may be a marker of preclinical PD. A survey of PD patients found that  24% reported nausea and 45% reported bloating, both symptoms of gastroparesis.1   Despite its frequency,  gastroparesis often goes unrecognized in PD.

As a potent dopaminergic agonist  which is administered subcutaneously and therefore bypasses the GI tract,  APOKYN (APO-go) is expected to have the ability to raise dopamine levels even  if gastric emptying is slowed as a result of PD.   The  hypothesis that delayed-ON episodes with oral PD medication may be due to  either gastroparesis or to impaired intestinal absorption will be explored as part  of the AM IMPAKT study. 

The study will enrol approximately  100 subjects at 12 study sites across the USA.   The primary endpoint is the change from baseline in average daily ’time  to turn ON’ (TTO) as recorded in each subject’s diary when they replace their  usual morning dose of levodopa with APOKYN (APO-go) injection. Treatment with APOKYN  (APO-go) injection will also be assessed in a sub-group of PD subjects  suffering from gastroparesis and delayed onset of levodopa action.  The sub-study is designed to evaluate whether  APOKYN (APO-go) may play a role in stimulating gastric emptying.  The findings from AM IMPAKT will be important  to determining whether APOKYN (APO-go) can assist in reversing early morning  ‘OFF’ in patients that experience delayed onset to their first morning dose of  L-dopa and provide further insights about whether a dopamine agonist that  bypasses the GI tract may have added benefit in addressing a common, yet often  undertreated, non-motor symptom of PD.

Stuart H. Isaacson, M.D. (Associate  Professor, Florida International University Herbert Wertheim College of  Medicine, Miami FL; Director, Parkinson’s Disease and Movement Disorders Center  of Boca Raton; Research Director, Marcus Neuroscience Institute, Boca Raton  Regional Hospital), the lead investigator on AM IMPAKT, commented: “We  are very excited to have commenced this important study. Our first patient was  recruited in December and we plan to have initial results available in  August.   We hope to show that APOKYN (APO-go) will provide  a valuable treatment option for PD patients with morning akinesia due to delayed  onset of levodopa by rapidly and reliably restoring their motor function and  enabling them to get on with their day.”

APOKYN (APO-go) injection has been  shown in previous clinical studies to provide rapid and reliable improvement in  motor symptoms of PD2; Mean changes from baseline were seen at 20  minutes with some changes being seen as early as 10 minutes  following injection.

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1. Stocchi F et al. Eur Neurol.  2010; 63(5):257-66.        
2. Pfeiffer RF. Lancet.  2003;2:107–116.        
3. Pfeiffer et al. Parkinsonism  Relat Disord. 2007;13:93–100.