PharmaTher Receives Notice Of Allowance For U.S. Patent Covering Ketamine For Parkinson's And Motor Disorders Treatment

Ketamine pharmaceuticals provider PharmaTher Holdings Ltd. PHRRF has been granted a Notice of Allowance by the U.S. Patent and Trademark Office (USPTO) for its “Compositions and Methods for Treating Motor Disorders” patent, intended to cover potential ketamine treatment of Parkinson’s disease and motor disorders causing involuntary or uncontrollable body actions. 

PharmaTher signed an exclusive license agreement with the University of Arizona to develop and commercialize the patent in August 2020. The results from the clinical study of ketamine for the treatment of levodopa-induced dyskinesia (LID) in patients with Parkinson’s would be made available in late-Q3 2022.

More specifically, the trial evaluated the safety, tolerability and efficacy of low-dose ketamine infusion for the treatment of LID in patients with Parkinson’s disease. Regarding efficacy, 100% of patients showed a reduction in dyskinesias (as measured by the Unified Dyskinesia Rating Scale) during the study period, compared to the pre-treatment baseline. 

As for safety, ketamine proved to be well tolerated with no serious adverse events reported. All adverse events were mild or moderate and reflected the expected side effects of ketamine administration. 

According to the company’s statements, the results are adequate to give an effect size in powering a Phase 3 clinical study. Accordingly, this would be PharmaTher’s next step, a trial for which it would use its proprietary ketamine intravenous drug, KETARX.

As expressed by CEO Fabio Chianelli, the patent application’s Notice of Allowance not only adds to the company’s IP portfolio covering novel uses, delivery forms and formulations of ketamine but also strengthens commercial opportunities with ketamine as a potential treatment for Parkinson’s disease and movement disorders.

Nonetheless, it should be noted that it is not guaranteed the FDA will support any potential request for an expedited path to approval or further development for ketamine in the treatment of Parkinson’s disease. That is to say, patent allowance is usually the last step before the patent is granted, yet this is not assured.

Disease And Novel Treatment

Parkinson’s disease affects over one million people in the U.S. and more than seven million worldwide. There is no known no cure for it, although some drug combinations are used to treat its symptoms. As a progressive neurogenerative disorder of the central nervous system that primarily affects the motor nerve system, treatments including levodopa and dopamine agonists restore the dopamine deficits in the brain and have been employed for almost 50 years. 

However, with continued treatment using levodopa, dose-limiting motor side-effects often emerge, including abnormal involuntary movements called Levodopa Induced Dyskinesias in about 50% of patients within five years after initiation of levodopa treatment and in almost all patients within ten years post-treatment initiation. These side effects often limit further dose increases in dopaminergic therapy.        

Ketamine is an FDA-approved drug widely used as an anesthetic agent either alone or combined with other anesthetic agents. The possible therapeutic effect of low-dose ketamine on levodopa-induced dyskinesia was noted in a retrospective analysis of Parkinson’s disease wherein patients who received ketamine for pain relief experienced an improvement in LID lasting several weeks beyond treatment [according to Sherman et al, 2016]. 

These results were corroborated in a test of low-dose ketamine in a rodent LID model, and this possible effect has also been examined in a controlled study [according to Bartlett et al, 2016].

Photo Courtesy of Luis Quintero on Pexels.