Phase 3 Trial Will Examine Mesdopetam as Treatment for Levodopa-induced Dyskinesia

Integrative Research Laboratories (IRLAB) is planning a Phase 2b/3 clinical trial of its investigational therapy mesdopetam (IRL790) to evaluate the therapy’s ability to reduce levodopa-induced dyskinesia (involuntary muscle movements) in people with Parkinson’s disease.

IRLAB is in the process of preparing applications to relevant regulatory agencies, with plans to start the trial in the second half of this year.

“The strategy planning for the Phase IIb/III-study with mesdopetam in Parkinson’s disease is now completed,” Nicholas Waters, CEO of IRLAB, said in a press release. “We have recently also secured financing for the study and initiated a collaboration with a highly reputable CRO [contract research organization].”

Parkinson’s is characterized by the death of neurons that make the neurotransmitter dopamine in the brain. Therapies that increase dopamine levels in the brain — such as levodopa — have been mainstays of Parkinson’s treatment for decades.

Some people treated with levodopa or its derivatives will develop uncontrolled, involuntary muscle movements, a phenomenon called levodopa-induced dyskinesia (LID).

Mesdopetam is being developed as a potential treatment for LID. It works by blocking specific dopamine receptors (D3 receptors), which have been implicated in the development of LID. It is thought that, by blocking only D3 receptors, LID can be minimized while other beneficial effects of dopamine treatment can be maintained (through its action on other receptors).

“Mesdopetam represents a new approach that, by inhibiting the mechanisms in the brain that has the most impact on levodopa dependent development of troublesome dyskinesias, and thus, can prevent these, improving the daily function in these severely affected patients,” said IRLAB chief marketing officer Joakim Tedroff.

The new clinical trial will be conducted at centers in Europe and the United States. It plans to enroll approximately 140 participants, who will be divided randomly into one of four treatment groups: three groups will receive different doses of mesdopetam, and the fourth will be given a placebo.

The trial’s main efficacy measurement will be the amount of time during which levodopa treatment works well and LID is not being experienced, referred to as “good on” time. This will be recorded by participants using 24-hour home diaries.

The design of this trial is similar to that of a previous Phase 2 trial (NCT03368170). In this trial, participants given mesdopetam at a dose of 7.5 mg twice daily had significantly longer average daily good on time than participants given a placebo (11.9 vs. 7.3 hours).

“When mesdopetam was given in addition to standard Parkinson medication, patients experienced considerably longer periods of good daily motor function without aggravated involuntary movements. This is highly relevant since involuntary, levodopa-induced dyskinesia is a major problem in the treatment of Parkinson’s disease preventing optimal treatment,” said Tedroff.

“The treatment effects seen in our Phase IIa study exceeds the results published for other treatment strategies in troublesome dyskinesias,” Waters added. “We believe that mesdopetam has a very good chance to offer a completely new and better treatment strategy for the large group of Parkinson’s patients with levodopa induced dyskinesia.”