Among the methods of drug delivery, subcutaneous injection is problematic when a single approved drug for a given condition is primarily available in injectable form. For some patients, injections may cause pain or disfigurement, or self-administering injections—perhaps multiple times per day—is simply too difficult for patients or caregivers. As a result, a significant percentage of the intended patient population may not benefit from the drug. Alternative drug delivery methods are therefore desirable.
For example, freezing episodes of Parkinson’s disease (PD) are characterized by acute immobility, can occur several times daily, and can last for several hours. These episodes may be triggered when treatments such as levodopa or enzyme inhibitors enter the bloodstream too slowly or insufficiently.
Currently, an acute rescue therapy exists to treat these freezing periods: apomorphine, the sole drug approved for this use—which is sold under the name Apokyn in the United States and Japan and under the name Apo-go in Europe and parts of Asia. Unfortunately, apomorphine is primarily available in an injectable form. Apomorphine is only stable in a highly acidic formulation, so the injection can result in painful reactions, including irritation and nodules at the injection site. Although many companies have attempted to develop non-injectable varieties of apomorphine, these attempts either failed or were commercially impractical.
But now, Cynapsus Therapeutics has developed a sublingual thin-film strip delivery system for apomorphine, which is similar in concept to Listerine breath strips. The strip dissolves in about 1.5 minutes, delivering the drug into the bloodstream in a similar time interval and concentration as an injectable dose. The strip system combines the drug’s acidic ingredients with other ingredients designed to eliminate irritation and enhance the speed of absorption. The treatment aims at eliminating self-injections, along with the injury and stress those injections entail.
At present, only a few prescription thin-film formulations are FDA-approved, but Cynapsus is aiming to join this list. The company must first submit a new drug application (NDA) to the FDA for approval of its formulation. This is expected to be accomplished by late 2015. After the approval, Cynapsus intends to partner the product for license or sale to a large pharmaceutical company.
Although treating the underlying cause of PD is the ultimate goal of basic science research, the daily realities of the PD patient and unmet clinical needs demand a renewed commitment to the development of symptomatic therapies. The point is to provide more effective and accessible treatments for the motor complications experienced by patients with PD as soon as possible. Unfortunately, current research suggests that disease-modifying drugs with breakthrough effectiveness remain perhaps 15 years away from routine clinical use.
Given that the global PD population is forecasted to double in the next decade due to the aging baby boomer generation, the unmet patient need for the treatment described above could be significant. It holds the potential to open a new chapter in PD treatment and to ensure that these patients’ freezing periods are quickly turned off, conveniently and easily.
About the author
Anthony Giovinazzo is President and CEO of Cynapsus Therapeutics, Inc., which is developing a non-injectable delivery of an approved drug to be used as a rescue therapy for freezing motor symptoms of Parkinson’s disease. He is one of the three original inventors and patent holders of the APL130277 sublingual strip system technology.
Filed Under: Drug Discovery