Highlights of KP415.A01 Oral HAP Trial Results:

  • Mean Drug Liking (Emax) of KP415 Prodrug (serdexmethylphenidate) at both 120 mg and 240 mg doses were statistically significantly lower than Focalin® XR at 80 mg
  • Mean Drug Liking (Emax) of KP415 Prodrug at 120 mg dose was statistically significantly lower than 60 mg of phentermine, a schedule IV controlled substance

CORALVILLE, IA, USA I September 11, 2018 I KemPharm, Inc. (NASDAQ:KMPH), a specialty pharmaceutical company focused on the discovery and development of proprietary prodrugs, today announced topline results from its oral human abuse potential (HAP) clinical trial of serdexmethylphenidate (SDX, a prodrug of d-methylphenidate, or KP415 Prodrug), the major active pharmaceutical ingredient (API) in KP415, its investigational ADHD product candidate that also contains d-methylphenidate. Results from the oral HAP trial (KP415.A01) indicate that the prodrug component of KP415 may have lower abuse potential compared to Focalin® XR (d-methylphenidate extended release capsules), a schedule II controlled substance, even when SDX is administered at oral doses up to 1.5 times higher than Focalin® XR on a molar basis. 

“The positive results from the oral HAP trial of SDX are another important milestone in the ongoing development of KP415 as we continue to advance a product candidate with properties that are clearly differentiated from currently marketed methylphenidate ADHD treatments, and with respect to abuse potential, perhaps all ADHD stimulant treatments,” said Travis Mickle, Ph.D., President and Chief Executive Officer of KemPharm. “Reducing the abuse potential of stimulant-based ADHD medications is viewed by prescribers as a key unmet need.  The oral HAP data are especially meaningful because we observed that SDX had lower Drug Liking at a higher dose, 240 mg, than an extended-release d-methylphenidate product.  It is quite unique to use an extended release comparator in these studies and simultaneously observing such a dramatic difference in effect, especially with a higher equivalent dose of stimulant. Additionally, SDX at 120 mg produced lower Drug Liking than phentermine, a schedule IV controlled substance.  These results together with the previously reported intravenous HAP data, suggest that SDX, the prodrug in both KP415 and KP484 product candidates, produces pharmacodynamic effects that are far less desirable to abusers in comparison to d-methylphenidate either when injected or taken orally as Focalin® XR, an extended release comparator, at supratherapeutic doses.”

Mickle added, “We look forward to reporting results from our final HAP trial soon, which will evaluate the abuse potential of SDX via the intranasal route. Results from the intranasal HAP trial are expected to be the final component of our New Drug Application (NDA) for KP415 with the FDA, which remains on track for submission to the FDA in the first quarter of 2019.  In addition, our preparation of the NDA and completion of the remaining elements of the clinical program for KP415 are taking place in parallel with an active partnering process for KP415 and KP484.”

About the KP415.A01 Trial:

The KP415.A01 oral HAP trial is the second of three human abuse potential trials to be completed and was conducted with SDX, the prodrug contained in KemPharm’s co-lead investigational product candidates, KP415 and KP484.  KP415.A01 was a single-center, Phase 1, randomized, double-blind, placebo-controlled, single-dose, 5-way crossover study to determine the abuse potential and pharmacokinetics of 120 mg and 240 mg doses of SDX in capsules compared to an 80 mg dose of Focalin® XR and a 60 mg dose of phentermine following oral administration in recreational stimulant users. Both Focalin® XR and phentermine were administered at twice the highest approved therapeutic dose as outlined in FDA guidance, and SDX at 240 mg was equivalent in d-methylphenidate content (on a molar basis) to 120 mg, or three times the highest approved dose of Focalin® XR.  The study consisted of a screening phase, a drug discrimination phase, and a treatment phase. Subjects were enrolled in the treatment phase if they were able to differentiate between the effects of a single oral dose of Focalin® XR and placebo in the drug discrimination phase. Forty-five (45) subjects completed all five treatment periods of the treatment phase.

In the trial, KemPharm observed statistically significant reductions in maximal Drug Liking (Emax) for SDX at doses of 120 mg and 240 mg (63 and 64 points respectively) when compared to twice the maximum daily clinical dose of Focalin® XR (80 mg, 82 points), and for the 120 mg dose of SDX when compared to twice the maximum daily clinical dose of phentermine (60 mg, 80 points).

In addition, retrospective endpoints of Take Drug Again (Emax) and Overall Drug Liking (Emax) were statistically similar for SDX compared to placebo at both doses. Feeling High (Emax) and Good Effects (Emax) were statistically significantly reduced for both doses of SDX compared to Focalin® XR and phentermine. Additionally, Take Drug Again (Emax) and Overall Drug Liking were significantly lower for SDX compared to phentermine at both doses and similar compared to Focalin® XR at both doses, though Focalin® XR was higher than placebo.

In summary, these findings suggest that oral administration of SDX results in effects that are lower compared to Focalin® XR, and at some dose levels, lower or similar to phentermine, a schedule IV controlled substance, as measured by multiple endpoints that are commonly used to assess human abuse potential.

A photo accompanying this announcement is available at http://www.globenewswire.com/NewsRoom/AttachmentNg/d09df797-11a2-46e6-bb7f-81dcf038a10e

These results are preliminary topline data and are subject to further analysis.  The full data and detailed results will be submitted for presentation at future scientific conferences and publication in peer-reviewed journals.

About KemPharm:

KemPharm is a specialty pharmaceutical company focused on the discovery and development of proprietary prodrugs to treat serious medical conditions through its proprietary LATTM (Ligand Activated Therapy) platform technology.  KemPharm utilizes its proprietary LAT platform technology to generate improved prodrug versions of FDA-approved drugs in the high need areas of ADHD, pain and other central nervous system disorders. KemPharm’s co-lead clinical development candidates are KP415 and KP484, both based on a prodrug of d-methylphenidate, but with differing extended-release/effect profiles for the treatment of ADHD.  In addition, KemPharm has received FDA approval for APADAZ®, an immediate-release combination product containing benzhydrocodone, a prodrug of hydrocodone, and acetaminophen.  For more information on KemPharm and its pipeline of prodrug product candidates visit www.kempharm.com or connect with us on Twitter, LinkedIn, Facebook and YouTube.

SOURCE: KemPharm