KemPharm announced the United States Patent and Trademark Office (USPTO) has recently issued two new patents to KemPharm governing methods of use and composition of matter for methylphenidate-based prodrugs. These newly-issued patents have an expiration date of December 9, 2037, which is an extension of approximately five years past the previously-issued patents generally describing compositions based on a prodrug of d-methylphenidate (serdexmethylphenidate or SDX). KP415 and KP484, KemPharm’s clinical development candidates for the treatment of attention deficit hyperactivity disorder (ADHD), are both SDX-based formulations.

In September 2019, KemPharm entered into the License Agreement with an affiliate of Gurnet Point Capital (GPC) for the exclusive worldwide rights to develop, manufacture and commercialize KemPharm’s product candidates containing SDX, including KemPharm’s ADHD product candidates, KP415 and KP484. GPC’s portfolio company, Corium will lead all commercialization activities for KP415.

The first patent (US 10,584,112) generally describes a specific stereoisomer compound of SDX and various other compositions. The second patent (US 10,584,113) generally describes compositions comprising unconjugated d-methylphenidate in combination with a specific stereoisomer compound of SDX.

“Issuance of these U.S. patents significantly strengthens the intellectual property portfolio governing KemPharm’s SDX-based product candidates, including our ADHD franchise, which is led by KP415,” said Travis C. Mickle, Ph.D., President and CEO of KemPharm. “The additional five years of patent protection afforded by the issuance of these patents is well-aligned with the ongoing effort by GPC and Corium to prepare KP415 for potential commercialization, if approved. Based on previous communications from FDA, the anticipated PDUFA date for KP415 is March 2, 2021.”

“We are pleased that these two additional patents have been issued for SDX, extending the potential life cycle of the product candidates, KP415 and KP484, to 2037,” said Dr. Sophie Kornowski, Senior Partner at GPC. “The extension of time significantly enhances the overall value of these innovative ADHD treatments and further supports the investment thesis for our partnership with KemPharm.”

KP415 consists of SDX co-formulated with immediate-release d-MPH and is designed to address unmet needs with the most widely-prescribed methylphenidate ADHD treatments, including earlier onset of action and longer duration of therapy, while avoiding unnecessary spikes in d-MPH concentrations that may be associated with adverse events. In addition, results from the various Human Abuse Potential trials for the SDX component of KP415 suggest that the prodrug alone may have lower abuse potential than relevant d-MPH comparators.

KP484 is KemPharm’s co-lead clinical development candidate being developed for the treatment of ADHD in patients that respond best when a very long duration of therapy is required. Similar to KP415, KP484 is based on SDX. Preclinical and clinical studies of KP484 have demonstrated that the prodrug may produce a longer duration release of d-MPH compared to the most prescribed methylphenidate products. KP484 has the potential to be the first new methylphenidate-based product being developed with the intent to address the specific needs of the adult ADHD population.