A clinical trial evaluating the efficacy, safety, tolerability, and pharmacokinetics of PRAX-944 in adults with essential tremor.

Study in progress
This research study is no longer accepting participants. The following details are for information only.

About this study

The main purpose of this research is to see if the study drug helps participants’ tremors and is safe and well-tolerated in participants with essential tremor (ET). An additional purpose is to see how much of the study drug gets into the blood, and how long it takes the body to get rid of it.

ET is a common neurological disorder, or illness related to the nervous system. It can cause shaking, also known as tremors, in the hands, arms, head, and voice. Calcium is a natural chemical in all brains that acts to change the function of some cells. One possible cause for ET is that calcium is overactive in the brain.

The study drug (PRAX-944) reduces the activity of calcium in the brain, which might restore the normal function of some cells and potentially help reduce the symptoms of ET.

Anticipated enrolment close date: December 2021

Who can take part

To be eligible to take part in this study you must meet the following criteria:

  • Male or non-pregnant, non-lactating female between 18 and 75 years of age, inclusive
  • Body mass index (BMI) at screening between 18 and 35 kg/m2, inclusive
  • Clinical diagnosis of ET consistent with Movement Disorders Society Criteria
  • A duration of ET of at least 3 years and with onset before the age of 65
  • Those currently receiving any medication for their ET must be willing and able to discontinue all but 1 tremor medication and be on a stable dose for at least 28 days
  • Willing to comply with medically acceptable method of contraception

What's involved

  • Medical history and current medications/treatments
  • Physical examination
  • Electrocardiogram (ECG)
  • Blood and urine samples for laboratory tests
  • Alcohol breath test
  • Columbia-Suicide Severity Rating Scale (C-SSRS)
  • The Essential Tremor Rating Assessment Scale (TETRAS)
  • Clinical Global Impression – severity (CGI-S) questionnaire
Person handling test tubes for research


All research in Australia involving human participants is reviewed by an independent group called a Human Research Ethics Committee (HREC). The ethical aspects of this research study have been approved by the Royal Melbourne Hospital HREC.

This study is being carried out according to the National Statement on Ethical Conduct in Human Research (2007). This statement protects the interests of people who agree to participate in human research studies.

The RMH Clinical Trials Centre
Clinical Trials Centre

The Clinical Trials Centre (CTC) is a dedicated, purpose-built space where we conduct clinical trials.

The CTC is located on Level 2 South. When you arrive, if you are unsure where to go, talk to one of our friendly volunteers or the information desk staff.

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