Intradermal Ketamine Patch Completes Pre-Clinical Phase, Advances To Clinical Studies

KETARX consists of hydrogel-forming microneedle arrays and an accompanying reservoir that can significantly increase the amount of drug permeating through the skin. The system aims at empowering patients to dose their medication remotely in a safe manner without the need to attend to a healthcare center, and future plans include incorporating anti-tampering and anti-abuse features.

In this completed stage, KETARX has demonstrated its ability to deliver ketamine over 40 hours. The system offers flexible dosing through increased size and drug load or concentration to better align with its administration methods available: intravenous injection, intradermal microneedle patch, and subcutaneous pump.  

KETARX was manufactured by PharmaTher’s partner LTS LOHMANN Therapie-Systeme AG, while the study was done at Aurigon Toxicological Research Center (ATRC). 

The company plans to initiate clinical studies by the end of 2022 towards determining pharmacokinetic parameters, dose range, dose response and tolerability that will support forthcoming Phase 2 and 3 clinical studies in depression, PTSD and pain indications. 

PharmaTher’s CEO Fabio Chianelli stated: “We are in the final stage of preparing for our clinical studies with KETARX, which we believe will transform how ketamine is used to treat underserved medical conditions in mental health, neurological and pain disorders.” 

Study Details & Results

The trial was focused on investigating the plasma concentration and pharmacokinetics of ketamine after the administration of PharmaTher’s proprietary ketamine patches to female Göttingen Minipigs. 

Local tolerance was examined as reflected by erythema, edema formation and other effects after removal of the pressure dressing. Concentration of ketamine in blood plasma was studied in samples collected up to 4 days after the administration.

Intramuscular injection was used to rapidly deliver a bolus dose of ketamine. While intravenous infusion, which requires specific equipment and expertise to administer, is the standard strategy to alter the speed and availability of the drug, the study demonstrated that KETARX applied directly to the skin was well tolerated and capable of delivering a dose over an extended period of time without needing any modifications or formulation enhancements. 

On the other hand, intradermal administration showed an extended delivery of ketamine -over 40 hours- with a slow increase of plasma levels over 18 hours and a slow decline for additional 24 hours.

The company noted that the small patch size used in the study supports the opportunity to increase dose through increased size, drug load or concentration of ketamine, and will allow increases in ketamine dosing to better align with intramuscular and intravenous administration. 

Importantly, no clinical symptoms, mortality or body weight differences were observed throughout the trial: local tolerance and histopathology assessment of the subjects within the control and ketamine groups showed only a minor difference but were both well-tolerated.

Photo courtesy of Andrea Piacquadio on Pexels and DanielTahar on Wikimedia Commons.