AzTrials
AzTrials

Opioid-Induced Nausea and Vomitting(OINV)Phase 4NCT07038551

Prophylactic Use of Naldemedine on Opioid-induced Nausea and Vomiting in Patients With Cancer: POSEIDON Study

A Phase 4 study testing Naldemedine in people with Opioid-Induced Nausea and Vomitting(OINV), run by International University of Health and Welfare at 20 sites in Japan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

Opioid analgesics can cause side effects such as constipation, nausea, and vomiting by acting on opioid receptors widely distributed in the peripheral nervous system. This can sometimes make it difficult to achieve and maintain pain relief and continue pain treatment. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
Naldemedine
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
120 participants
Where
20 sitesJapan
Study dates
20 Jun 2025to 13 Feb 2026
Phase
Phase 4
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patients who can be expected to initiate regular administration of opioid analgesics (tramadol, morphine, oxycodone, hydromorphone) for cancer pain and continue for 7 days or more.
  • Patients who are 18 years of age or older at the time of obtaining consent
  • Patients who can take oral medications, food, and beverages
  • Patients who are considered capable of self-recording in the patient's diary (proxy recording in the patient's diary is acceptable if the patients are capable of self-assessment).
  • Patients who are not expected to have a rapid change in their condition during the study period.
  • Patients who can obtain written consent to participate in the study of their own will

Who cannot join

  • Patients who have used opioid analgesics within 28 days prior to the date of consent
  • Patients who have taken or are currently taking naldemedine
  • Patients who have nausea and vomiting of CTCAE grade 2 or higher at the time of obtaining consent
  • Patients who have taken the following antiemetic drugs within 7 days prior to the date of consent Metoclopramide, domperidone, H1 histamine receptor antagonists, phenothiazine antipsychotics (chlorpromazine, levomepromazine, prochlorperazine), haloperidol, atypical antipsychotics (perospirone, risperidone, olanzapine), serotonin 5HT3 receptor antagonists (ondansetron, granisetron, ramosetron, palonosetron), corticosteroids (dexamethasone), scopolamine hydrobromide, NK1 receptor antagonists (aprepitant, fosaprepitant, fosnetupitant)
  • Patients who have received cancer chemotherapy that is certain to affect nausea and vomiting within 14 days prior to the date of consent or who are scheduled to receive such therapy within the study period. Cancer chemotherapy that is certain to affect nausea and vomiting will be defined as follows:
  • ① Initial administration of a therapeutic regimen containing irinotecan (CPT-11)
Show all 21Show fewer
  • ② Other cancer chemotherapy that is considered certain to affect nausea and vomiting.
  • However, the following cases may be considered as not affecting defecation
  • Chemotherapy with the same regimen as the previous course or chemotherapy with the same drug and dose, and there was no moderate or greater nausea and vomiting (CTCAE v5.0 Grade 2 or higher) during the previous course or previous chemotherapy.
  • Patients who have received oral anticancer agents (e.g. TS-1) daily and have not had moderate or severe nausea and vomiting (CTCAE v5.0 Grade 2 or higher) for at least 1 week from the start of oral chemotherapy to the date of consent.
  • Pregnant or lactating patients
  • Patients with suspected hypersensitivity to opioid receptor antagonists such as naldemedine, naltrexone, methylnaltrexone, and naloxone
  • Patients with contraindications listed in the package inserts for naldemedine and opioid analgesics (tramadol, morphine, oxycodone, hydromorphone)
  • Patients participating or scheduled to participate in clinical trials or other interventional studies
  • Patients with gastrointestinal obstruction or suspected gastrointestinal obstruction, or patients with a history of gastrointestinal obstruction and a high risk of recurrence
  • Patients who have undergone surgery or treatment (e.g., nerve block) that affects gastrointestinal function, or radiation therapy to the head, intestinal tract, or pelvis within 14 days prior to the date of consent acquisition, or patients who are scheduled to undergo such treatment during the observation period
  • Patients with medically significant cardiovascular, respiratory, hepatic, or renal dysfunction based on history, clinical laboratory values, electrocardiogram, or physical examination, who are judged inappropriate to participate in the study
  • Patients with symptomatic intracranial conditions (such as brain metastases or leptomeningeal disease)
  • Patients with suspected dysfunction or impairment of the blood-brain barrier
  • Patients for whom it is difficult to explain the contents of the study or obtain consent due to cognitive impairment or psychiatric illness
  • Patients who are judged by the principal investigator or sub-investigator to be inappropriate to participate in this study based on other concomitant therapies or medical findings

Trial locations and contacts

20 sites in 1 country.

20 sites in 1 country

Japan20 sites
  • Kansai Rosai Hospital

    Amagasaki, Hyōgo

  • Beppu Medical Center

    Beppu, Oita Prefecture

  • National Cancer Center Hospital

    Chuo Ku, Tokyo

  • National Hospital Organization HIMEJI M edical Center

    Himeji, Hyōgo

  • Hiroshima Prefectural Hospital

    Hiroshima, Hiroshima

  • Iizuka Hospital

    Iizuka, Fukuoka

  • Kindai University Nara Hospital

    Ikoma, Nara

  • St. Marianna University School of Medicine

    Kawasaki, Kanagawa

  • Kyoto University Hospital

    Kyoto, Kyoto

  • IUHW Narita Hospital

    Narita, Chiba

  • Niigata Cancer Center Hospital

    Niigata, Niigata

  • Hyogo Prefectural Nishinomiya Hospital

    Nishinomiya, Hyōgo

  • Osaka Red Cross Hospital

    Osaka, Osaka

  • Osaki Citizen Hospital

    Ōsaki, Miyagi

  • Cancer Institute Hospital of Japanese Fo undation for Cancer Research

    Tokyo, Tokyo

  • Showa University Koto Toyosu Hospital

    Tokyo, Tokyo

  • Toyama University Hospital

    Toyama, Toyama

  • Toyohashi municipal hospital

    Toyohashi, Aichi-ken

  • University of Tsukuba Hospital

    Tsukuba, Ibaragi

  • Kanagawa Dental University Yokohama Clinic

    Yokohama, Kanagawa

Other trials in Japan

About this study

Official title: Prophylactic Use of Naldemedine on Opioid-Induced Nausea and Vomiting in Patients With Cancer: A Multicenter, Randomized, Placebo-Controlled, Double-Blind Study

Opioid analgesics can cause side effects such as constipation, nausea, and vomiting by acting on opioid receptors widely distributed in the peripheral nervous system. This can sometimes make it difficult to achieve and maintain pain relief and continue pain treatment. Among these side effects, nausea and vomiting are specifically referred to as opioid-induced nausea and vomiting (OINV). OINV is known to occur during the initial administration or dose escalation of opioid analgesics, and it not only decreases the quality of life for patients but also reduces adherence to opioid analgesics, which can have a negative impact on pain management. Therefore, appropriate management is crucial.

While the administration of conventional antiemetic drugs is recommended for the treatment of OINV, there is a lack of high-quality studies evaluating their effectiveness, and studies comparing treatment effects with a placebo have not been reported.

The objective is to verify the effectiveness of naldemedine in preventing OINV in patients starting opioid analgesics for cancer

Being tested
Naldemedine, Placebo
Keywords
Nausea, Vomiting, Constipation
Medical subject headings
Nausea, Vomiting, Constipation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • NaldemedineDrug

    over-encapsulated capsule of either 0.2 mg of naldemedine

  • PlaceboDrug

    over-encapsulated capsule of placebo

Study groups in NCT07038551
Study groupRoleWhat they receive
NaldemedineActive comparatorNot described
Receives: Drug: Naldemedine
PlaceboPlacebo comparatorNot described
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. The proportion of patients who achieved a Complete Response on Day 5 (CR5), defined as no vomiting up to 120 hours after starting opioid analgesic and no use of rescue antiemetic medications.

    Measured: 120 hours

Secondary outcomes (19)
  1. The proportion of patients who achieved a Complete Response at CR1, CR2, CR3, and CR7 (defined as no vomiting up to 24, 48, 72, and 168 hours after starting opioid analgesics, respectively, and no use of rescue antiemetic medications)

    Measured: 24, 48, 72, and 168 hours

  2. Change in nausea NRS from baseline

    nausea NRS[0-10]: Higher scores indicate greater nausea intensity

    Measured: Day 1, 2, 3, 5, and 7

  3. Average duration of nausea per day

    Measured: Day 1, 2, 3, 5, and 7

  4. Proportion of patients who vomited at least once after starting opioid analgesics

    Measured: 24, 48, 72, 120, and 168 hours

  5. Proportion of patients who used rescue antiemetic medicines

    Measured: 24, 48, 72, 120, and 168 hours

  6. Number of times rescue antiemetic medicines were used

    Measured: 24, 48, 72, 120, and 168 hours

  7. Proportion of patients with Spontaneous Bowel Movement (SBM: spontaneous bowel movement) of 3 or more per week

    Measured: 7days

  8. Proportion of patients with Spontaneous Bowel Movement (CSBM: SBM without sensation of incomplete evacuation) of 3 or more per week

    Measured: 7days

  9. Proportion of patients experiencing a sensation of incomplete evacuation in 25% or more of defecation

    Measured: 7days

  10. Proportion of patients with SBM without straining of 3 or more per week

    Measured: 7days

  11. Proportion of patients experiencing a sensation of straining in 25% or more of defecation

    Measured: 7days

  12. Proportion of patients with SBM without sensation of straining or sensation of incomplete evacuation of 3 or more per week

    Measured: 7days

  13. Proportion of patients experiencing a sensation of straining or sensation of incomplete evacuation in 25% or more of defecation

    Measured: 7days

  14. Number of times rescue laxatives or enema or digital evacuation were used

    Measured: 7days

  15. Proportion of patients with a Bowel Function Index of less than 28.8

    Measured: 7days

  16. Change in Bowel Function Index from baseline

    Measured: 7-11days

  17. the percentage of patients whose satisfaction worsened

    Measured: 7-11days

  18. Change in Global Quality of Life score and scores for each subscale evaluation of the EORTC-QLQ-C15 PAL

    Measured: 7-11days

  19. Change in pain NRS from baseline

    pain NRS[0-10]: Higher scores indicate greater pain intensity

    Measured: 1,2,3,5,7days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Jun 2025
  2. Study start20 Jun 2025
  3. Primary completion13 Feb 2026
  4. Study completion13 Feb 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
120 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07038551
Sponsor's protocol ID
2024U0160
Status last verified
May 2026
First submitted
18 Jun 2025
Last updated
3 Jun 2026
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: De-identified individual participant data (IPD) underlying the results reported in this study will be shared. These data will include those related to the primary outcome (complete response within 120 hours \[CR5\]) as well as secondary outcomes, including complete response rates at different time points (CR1, CR3, and CR7), nausea Numerical Rating Scale (NRS) scores, vomiting events, and use of rescue medications.

Publications

  • Ishihara Y, Ohira M, Hokabe M, Yoshino S, Iwashita K, Takahashi K, Tomita N, Uneno Y, Kataoka S, Kurihashi T, Satomi E, Hamano J, Higashibata T, Kosugi K, Hirakawa M, Kajiura S, Ogihara S, Kida M, Morita T, Koretaka Y, Sonoyama T, Oyamada S, Nakajima A, Kessoku T. Multicentre, double-blind, randomised, placebo-controlled study on the prophylactic use of naldemedine for opioid-induced nausea and vomiting in patients with cancer (POSEIDON study): a protocol paper. BMJ Open. 2026 Jul 17;16(7):e114092. doi: 10.1136/bmjopen-2025-114092.

    PubMed 42468954

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Naldemedine in people with Opioid-Induced Nausea and Vomitting(OINV), run by International University of Health and Welfare at 20 sites in Japan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 3 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 20 sites in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

The proportion of patients who achieved a Complete Response on Day 5 (CR5), defined as no vomiting up to 120 hours after starting opioid analgesic and no use of rescue antiemetic medications. (time frame: 120 hours). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07038551, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jun 2026.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in