PharmaTher Seeking Trial of Ketamine for Levodopa-Induced Dyskinesia

PharmaTher is seeking regulatory approval to launch a clinical trial of the painkiller ketamine for levodopa-induced dyskinesia — the uncontrolled, involuntary movements that affect as many as 80% of Parkinson’s patients following treatment.

The company, which focuses on the research and development of psychedelic pharmaceuticals, has submitted an investigational new drug (IND) application to the U.S. Food and Drug Administration (FDA) to initiate a study of low-dose ketamine, an anesthetic available by prescription in the U.S.

The proposed Phase 2 study would evaluate the safety, efficacy, and pharmacokinetics — or how a drug moves into, through, and out of the body — of ketamine in low doses for levodopa-induced dyskinesia (LID).

Dyskinesia is associated with the long-term use of levodopa, a Parkinson’s treatment that increases dopamine levels in the brain. Data shows that as many as 80% of Parkinson’s patients on levodopa will develop dyskinesia after 10–12 years of treatment.

If the results of the proposed trial are positive, PharmaTher plans to request a meeting with the FDA to obtain an agreement for a Phase 3 clinical study under the IND’s expedited regulatory pathway.  

“The submission of our IND application with the FDA is an important milestone as it provides us with a solid foundation to advance our ambition in commercializing ketamine and unlocking its therapeutic potential through novel uses, formulations and delivery methods,” Fabio Chianelli, CEO of PharmaTher, said in a press release.

Chianelli said PharmaTher also is investigating ketamine as a potential treatment for other neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), as well as for mental illness and chronic pain.

Ketamine is approved by the FDA as an anesthetic and pain-relieving agent. In preclinical research conducted by scientists at the University of Arizona, low-dose ketamine was found to alleviate abnormal movements in a mouse model of LID.

PharmaTher announced in October that it had entered an exclusive licensing agreement with the University of Arizona to develop ketamine as a treatment for LID in Parkinson’s patients.

Late last year, the company filed a request to meet with the FDA to receive guidance on advancing the clinical development of ketamine at sub-anesthetic doses to treat LID.

The planned Phase 2 trial is slated to enroll up to 36 participants at up to eight study sites in the U.S., according to PharmaTher. The participants will be randomly assigned to receive either low-dose ketamine or the sedative midazolam for eight weeks.

The primary goal of the study will be a change in the Unified Dyskinesia Rating Scale total score from the study’s start (baseline) to week eight, or about two months. 

The study’s secondary goals include a change in the Unified Dyskinesia Rating Scale total objective, motor, and dyskinesia scores, and total daily off times after eight weeks of treatment. Off times are periods when Parkinson’s symptoms return despite medication use.