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RecruitingLast updated: 16 February 2026

GENOS: A study to determine whether it is possible to provide more personalised pain relief for people with incurable or advanced cancer who are taking opioids for the cancer painA Pragmatic Registry Trial Investigating Pharmacogenomics In Opioid Switching For Cancer Pain

Trial purpose

Medical clipboardSide effect and wellbeing

Tumor type

Multi-Cancer Multi-Cancer

Age

People18+

Trial acronym

GENOS

Clinical summary

Summary

Cancer pain is a prevalent and distressing symptom, with opioids being the primary treatment. However, individual responses to opioids vary greatly, causing unpredictable pain relief and adverse effects. Approximately 30-40% of cancer patients experience "opioid failure", necessitating an "opioid switch" due to inadequate pain relief or toxicity.

This study will investigate biological measures (biomarkers) to develop precision opioid prescribing for cancer patients. This is a registry trial.

You may be eligible for this study if you are an adult who has incurable/advanced cancer with pain related to cancer and you are currently taking opioid medications to treat your cancer pain.

Study details
All participants in this study will be seen several times, and this may be either during or in addition to their usual care - once at the time of enrolment into the study, then at 2, 4, 6 and 8 weeks after their enrolment. Participants who are identified as candidates for opioid switching will also be seen at 72 hours before the opioid switch, at the time of the switch and again within 3-14 days after the opioid switch.

On each of these days particpants will be asked for clinical information and to complete some questionnaires about their symptoms (questions about pain releif, side effects and levels of function) and given questionnaires to complete regarding their symptoms and pain levels. One blood test will also be taken during this time, which includes samples for opioid levels in the blood, markers of inflammation and genetic markers. If particpants undergo opioid switch, an optional additional blood test will be taken to measure opioid levels in the blood.

It is hoped that this research will determine whether it is possible to provide more personalised pain relief based on a patient's clinical, biological and genetic information. The effect of the opioid switching on pain levels up to 2 months after the medication change will also be assessed to determine whether the change has any impact on participants pain levels. 

Conditions

This trial is treating people with incurable or advanced cancer with pain related to cancer, and are currently taking opioid medication to treat the cancer pain

Eligibility

Inclusion

Diagnosis of incurable/advanced cancer
Pain related to cancer and/or its treatment requiring opioid therapy
Currently on oxycodone or morphine and taken for greater than or equal to 3 days as first regular ongoing strong slow-release opioid
English speaking with sufficient reading and writing ability to complete the study questionnaires
Life expectancy > 8 weeks

Exclusion

Slow-release opioid used primarily for reasons other than pain (e.g., opioid replacement therapy, breathlessness)

Inclusion

  • You have had treatment, but your cancer has come back (relapsed or recurrent).
  • Your cancer has spread to other parts of the body (metastatic) or has grown into nearby parts of the body (locally advanced).
  • Your cancer has not spread to other parts of the body, but it is not possible to perform surgery to remove it (unresectable).
  • You have had a certain type of treatment or surgical procedure.
  • You have the type of cancer, symptoms, or health risks that this clinical trial is focused on.

Exclusion

  • You have had certain treatments, surgical procedures or drugs.
Message

Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.

Participating hospitals

Recruiting hospitals

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More information

Trial Identifiers

Information on this page is partially produced from ANZCTR *. View further details about this trial on the registry via the links below:

Trial sponsor

Peter MacCallum Cancer Centre

Scientific Title

A Pragmatic Registry Trial Investigating Pharmacogenomics In Opioid Switching For Cancer Pain

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Cancer Connect

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Information for family, friends and carers

When you are considering a cancer clinical trial, it is a good idea to discuss it with your family, friends or carers.

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