FDA has approved Apokyn (apomorphine) as an injectable drug for treating Parkinson's patients during episodes of "hypomobility," so-called "off periods" in which the patient becomes immobile or unable to perform activities of daily living. Apokyn was given priority review because injectable apomorphine is the first therapy approved to treat these episodes acutely (during the episode). Apokyn was also designated as an orphan product.
An estimated 1.5 million Americans have Parkinson's disease, which results in tremors, rigidity, postural instability, slowness, and difficulty moving.
Within 3 to 5 years of treatment with standard Parkinson's drug treatments, about ten percent of patients experience episodes of hypomobility (e.g., inability to rise from a chair, to speak, or to walk). The episodes can occur toward the end of a dosing interval with standard background medications (so-called "end-of-dose wearing off") or at unpredictable times (spontaneous "on/off").
Apokyn was designated an orphan drug in l991 to treat the ten percent, or about 112,000 Parkinson's patients who progress to stage four and experience the severe on/off motor fluctuations unresponsive to other therapies. Orphan drugs are drugs that treat a rare disease or condition which affects fewer than 200,000 patients in the U.S. After receiving FDA approval, orphan drugs are eligible for seven years of exclusive marketing.
The effectiveness of Apokyn in the acute symptomatic treatment of both types of recurring episodes of hypomobility or "off" episodes associated with advanced Parkinson's disease was established in three randomized, controlled trials. On average, patients participating in these trials had had Parkinson's disease for 11.3 years and were being treated with L-dopa and at least one other agent, usually an oral dopamine agonist.