A Phase 2 interventional study of Cebranopadol and Cebranopadol in Chronic Pain, Pain and Opioid Withdrawal (Disorder), sponsored by Adneuris Therapeutics, Inc.. Recruiting at 2 sites in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-23.
Sponsored by Adneuris Therapeutics, Inc. · Phase 2, Interventional, and Treatment
This Phase 2 study will evaluate whether multiple doses of cebranopadol suppress opioid withdrawal signs and symptoms compared with placebo in adults with chronic pain who are physically dependent on prescribed opioids. Participants whose physical dependence is confirmed will be assigned by chance to one of two cebranopadol dose regimens or matching placebo. The study will also evaluate pain, safety and tolerability, and cebranopadol pharmacokinetics.
Participants will complete outpatient screening followed by an inpatient treatment period and a safety follow-up telephone call. Within 30 days of initiating screening, participants will be admitted to the clinical research site.
Their current prescribed opioid will be withheld after the scheduled morning dose on Day -1, and withdrawal signs and symptoms will be assessed using the Clinical Opiate Withdrawal Scale (COWS) and Subjective Opioid Withdrawal Scale (SOWS) to confirm physical dependence. Participants meeting the predefined withdrawal criteria will resume their prescribed opioid as specified in the protocol and will subsequently be randomized on Day 1. Eligible participants will be randomized 1:1:1, stratified by current prescribed daily opioid regimen (50-75 morphine milligram equivalents [MME] versus >=76 MME), to cebranopadol 400 micrograms in the morning plus 200 micrograms in the evening, cebranopadol 400 micrograms twice daily, or matching placebo twice daily. Study drug is administered every 12 hours for 48 hours. Participants remain inpatient during treatment and undergo withdrawal, pain, safety, and pharmacokinetic assessments. Rescue medication is available according to protocol-defined criteria. Participants may resume their current prescribed opioid at least 12 hours after the final study-drug dose and are monitored until discharge on Day 4. A safety follow-up telephone call occurs on Day 7 (+/-2 days) after the last study-drug administration
2,998 studies on the registry are indexed under Chronic Pain; 706 are open to participants now.
This study's planned enrollment of 45 is below the median of 60 across 2,209 interventional studies indexed under Chronic Pain.
Browse Chronic Pain studies →Adneuris Therapeutics, Inc. is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Key Exclusion Criteria:
Cebranopadol 400 micrograms orally in the morning and 200 micrograms orally in the evening on Day 1 and 2; final dose on the evening of Day 2
Drug: Cebranopadol
Cebranopadol 400 micrograms orally twice daily on Day 1 and 2; Final dose on the evening of Day 2.
Drug: Cebranopadol
Matching placebo orally twice daily on Day 1 and 2 days; Final dose on the evening of Day 2.
Drug: Placebo
Administration orally twice daily on Days 1 and 2 and according to the assigned regimen.
Administration orally twice daily on Days 1 and 2 and according to the assigned regimen.
Administration orally twice daily on Day 1 and 2.
Clinical Opiate Withdrawal Scale (COWS) Total Score Maximum Effect (Emax) from 0 to 48 hours
Maximum (peak) COWS total score observed during the 48-hour assessment period. after the first study drug dose, using the protocol-specified adjustment for rescue medication. The COWS is an 11-item clinician-rated scale used to assess opioid withdrawal signs and symptoms. Total scores range from 0 to 48, with higher scores indicating greater withdrawal severity.
Time frame: From first study-drug administration through 48 hours after the first dose]
Area under the curve of COWS Total Score from 0 to 48 hours (AUC0-48)
Area under the curve (AUC) of COWS total score-time curve from 0 to 48 hours after the first study drug dose, using the protocol-specified adjustment for rescue medication. COWS total scores range from 0 to 48, with higher scores indicating greater withdrawal severity.
Time frame: From first study-drug administration through 48 hours after the first dose.
Proportion of Participants Meeting the COWS Responder Criteria
Proportion of participants meeting the protocol-defined COWS responder criteria based on average COWS total score and absence of opioid rescue medication through 24 hours. A responder is defined as having at least 30 percent improvement and/or a COWS total score of 5 or less and/or transition to a lower withdrawal severity category from baseline, without opioid rescue medication through 24 hours.
Time frame: From first study-drug administration through 24 hours after the first dose
Maximum Change From Baseline in COWS Total Score by Dosing Day.
Maximum change from baseline in COWS total score by dosing day during Day 1, Day 2.
Time frame: Baseline- From first study-drug administration through 72 hours after the first dose
Area Under the Curve of COWS Total Score From 0 to 24 Hours (AUC0-24) COWS Total Score AUC0-24and From 0 to 72 Hours (AUC0-72).
Area under the curve (AUC) of COWS total scores, through 24 hours; and 72 hours after the first study drug dose, using the protocol-specified adjustment for rescue medication.
Time frame: 0-24 hours and 0-72 hours after first study-drug administration
Maximum Subjective Opioid Withdrawal Scale (SOWS) Total Score.
Subjective Opioid Withdrawal Scale total score assessed using Emax, maximum change from baseline by dosing day, and area-under-the-curve summaries. The SOWS is a participant-reported measure of opioid withdrawal symptoms. Total scores range from 0 to 64, with higher scores indicating greater withdrawal severity.
Time frame: Through 72 hours after first study-drug administration]
Participants Receiving Rescue Medication
Proportion of participants who receive protocol-permitted rescue medication for withdrawal signs and symptoms.
Time frame: Through the inpatient assessment period, up to 72 hours after first study-drug administration
Time to First Rescue Medication for Withdrawal
Time from first study-drug administration to first administration of protocol permitted rescue medication to manage withdrawal symptoms
Time frame: Up to 72 hours after first study-drug administration
Opioid Rescue Medication Use
Number of opioid rescue medication doses and total opioid rescue medication use expressed in morphine milligram equivalents (MME).
Time frame: Up to 72 hours after first study-drug administration]
Area Under the Curve of "Pain Right Now" Numeric Pain Rating Scale Score From 0 to 48 Hours (AUC0-48)
Area under the curve for of "Pain Right Now" Numerical Pain Rating Scale (NPRS) pain 'right now' scores from 0 to 48 hours after the first study drug dose, using the protocol-specified adjustment for rescue medication. NPRS scores range from 0 (no pain) to 10 (worst possible pain).
Time frame: 0 to 48 hours after first study-drug administration
Proportion of Participants With at Least a 2-Point Improvement from Baseline in Average 24-Hour Pain.
Percentage of participants with at least a 2-point improvement from baseline in the NPRS rating of average pain during the previous 24 hours.
Time frame: 0 to 72 hours after first study-drug administration
Change From Baseline in Average/Worst/Least Pain During the Previous 24 Hours
Change from baseline in participant-reported Average/Worst/Least pain during the previous 24 hours on NPRS.
Time frame: 0 to 72 hours after first study drug administration
Non-Opioid Rescue Medication Use
Number of non-opioid rescue medication doses and total non-opioid rescue medication use summarized by medication type.
Time frame: Up to 72 hours after first study-drug administration]
Start is estimated for Oct 2026; primary completion for Mar 2027, 5 months later.
Of 64 phase 2 interventional studies under Chronic Pain, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 52. This study's planned 5 months is below that.
Start moved once since we started tracking on Sep 25, 2026: Sep 2026 → Oct 2026, on Oct 23, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Cebranopadol
Adneuris Therapeutics, Inc.