Major trial to study medicinal cannabis and endometriosis in Australia

Researchers in Australia have received funding for a world-first clinical trial into medicinal cannabis and endometriosis.

Researchers at Western Sydney University have received a grant of $660,000 for a three year study of medicinal cannabis as a potential treatment for endometriosis.

The grant will fund a clinical trial, laboratory work investigating the endocannabinoid system (ECS) and inflammatory markers, as well as a health economics component exploring the potential cost-benefits of medicinal cannabis for treating endometriosis.

Endometriosis is a disease in which the tissue similar to the lining of the uterus grows outside of the uterus, causing severe pain, inflammation, fatigue and in some cases infertility whilst negatively impacting a person’s quality of life. 

The disease affects approximately 10% (190 million) of reproductive-age women and those that identify as gender diverse globally. 

Despite its prevalence there are very few effective treatments and the cause of endometriosis remains largely unknown.

“The purpose of this double-blind randomised controlled trial is to determine if medicinal cannabis, either a cannabidiol (CBD) isolate or a balanced oil containing both CBD and delta-9-tetrahydrocannabinol (THC), can reduce pelvic pain and other symptoms of endometriosis when compared to a placebo oil, which we believe is the first time this has been done,” said principal investigator of the study, Associate Professor Mike Armour, NICM Health Research Institute, Western Sydney University.

“Our trial will also be the first ever to use special ultrasound scans called sonovaginography to map and track the size and location of endometriosis lesions over time to see if they change in response to treatment. We will also be investigating any dysfunction in the endocannabinoids system that appears may contribute to symptoms in those with endometriosis.”

Recent research indicates that cannabis may have a positive effect on the body’s ECS, which is involved in regulating pain, inflammation, and immune function. 

This system is composed of receptors throughout the body, including the reproductive organs, and cannabis compounds, such as CBD and THC, interact with these receptors to produce a variety of effects.

“Various phytochemicals, mainly CBD, from cannabis have well described analgesic, anti-inflammatory, and antidepressant actions, and can also reduce anxiety and nausea. Cannabis use in other chronic pain conditions has resulted in a “substitution effect” of pharmaceuticals, commonly opioid analgesics, by cannabis,” Associate Professor Armour continued.

“Our previous research has shown that people living with endometriosis in Australia and New Zealand are using cannabis, mostly from illicit sources, to manage their pain and other associated symptoms.

“These people self-reported positive experiences with cannabis use including reduction in pain, improvements in sleep, mood and gastrointestinal functions and credited it with allowing them to effectively manage their endometriosis symptoms and live a better quality of life.

He added: “However, there is still a lot we don’t know about how or why cannabis may affect endometriosis symptoms and possibly slow lesion progression. The trial will allow us to determine the effective dosage range, ideal THC to CBD ratio, duration of treatment and so forth. We are delighted that the Wilson Foundation is funding this ground-breaking trial which will answer these important questions.”

The grant has been provided by the Wilson Foundation which funds innovative research into mental and physical health. The Foundation believes this research will provide critical evidence to determine if medicinal cannabis is a safe, effective, and accessible treatment for patients with endometriosis.

Karen Wilson, chair, the Wilson Foundation, commented: “It is imperative that we invest in progressive approaches in the treatment of endometriosis. We are optimistic that this trial will create improved outcomes for those with this systemic disease.”

OnTracka App will provide in-kind support for electronic data capture for the study and the medicinal cannabis products THC and CBD will be provided in kind by the Australian Natural Therapeutics Group.

Following ethics approval, the trial will commence recruitment this winter and will involve 126 people living in Sydney with endometriosis who will be randomly assigned to receive either medicinal cannabis or placebo over a period of 26-weeks, with a 52-week follow up.

Endometriosis Australia’s CEO Maree Davenport says this study is a crucial step towards building a better understanding of how medicinal cannabis may be used as an effective treatment option for those living with endometriosis.

“We welcome this significant investment in endometriosis research. Treatment options for severe endometriosis are limited and often involve invasive and costly surgeries alongside powerful medications that can have detrimental side effects. Non-addictive pain management options for acute patients are considered an urgent research priority in endometriosis, both in Australia and internationally,” said Davenport.

Long-time endometriosis advocate and co-founder and Director of Endometriosis Australia, Donna Ciccia, added: “As a person living with endometriosis and the impact it has left on my body, I know all too well how often we struggle to find effective treatment options. Using medicinal cannabis under the care of my GP, I’ve found it has helped me manage some of my symptoms. This study has the potential to provide a safe and accessible alternative for the community.”

The Medicinal Cannabis Endometriosis Study is a multidisciplinary project that will involve academics, researchers, medical professionals and endometriosis advocates from Western Sydney University, Deakin University, Macquarie University, University of Tasmania, UNSW Sydney, the University of Sydney, the Medical Research Institute of New Zealand, Royal Hospital for Women in Randwick, Endometriosis Australia and the National Endometriosis Clinical and Scientific Trials Network.

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