Chemotherapy-induced nausea and vomiting

This NSW Government-funded trial is evaluating the potential of a cannabis medicine to prevent nausea and vomiting in patients undergoing chemotherapy.


To date, studies in the area of chemotherapy-induced nausea and vomiting have been carried out using smoked cannabis or oral synthetic cannabis medicines, with most studies featuring very small numbers of participants. To assess the effectiveness of these cannabis medicines, the trials compared them with outdated antiemetic (anti-vomiting) medical treatments.

Although modern antiemetic medical treatments have significantly reduced these unpleasant symptoms, approximately half of all people undergoing potent intravenous chemotherapy still experience nausea and one-third still experience vomiting.

About the chemotherapy-induced nausea and vomiting trial

The NSW Government funded trial will play a critical role in developing a better understanding of how cannabis medicines may provide symptom relief for patients undergoing potent intravenous chemotherapy, where standard treatments have proven ineffective. It will also assess any side effects that occur during the treatment course. The study consists of two stages: a pilot phase II study and a definitive phase III trial, with a total of 250 patients to be enrolled.

The clinical trial is using an oral, plant-derived, pharmaceutical-grade capsule containing a consistent ratio of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), developed by a Canadian cannabis-medicine company.

The trial is being conducted in accordance with the standard ethical process for clinical trials and has received regulatory approval. It has been reviewed and approved by an appropriate Human Research Ethics Committee.

Clinical Associate Professor Peter Grimison, a medical oncologist from Chris O’Brien Lifehouse and The University of Sydney, is leading the trial alongside a research team of specialists in cancer, addiction medicine and clinical toxicology.

Update on the trial

The first (pilot) stage enrolled and treated 81 patients at Chris O’Brien Lifehouse and other leading NSW cancer centres.

The pilot phase results were published in Annals of Oncology in August 2020. The addition of oral THC:CBD to standard nausea and vomiting medicines was associated with less nausea and vomiting but additional side-effects. Most participants in the trial preferred THC:CBD to placebo.  

Based on the results from the first stage, the trial progressed to Stage 2. Overall, 152 patients were enrolled in the study, with recruitment ceasing at the end of August 2022. This trial is no longer recruiting participants.

Continued free treatment after the trial

The trial has been specifically designed to allow patients continued access to the cannabis medicine, free of charge, after they have concluded the trial. A statistician will review the patient data to determine if they were receiving the cannabis medicine or the placebo. If they were receiving the medicine and it proved effective, the patient will be supplied sufficient cannabis medicine for all subsequent cycles of that specific chemotherapy treatment.