Dexmedetomidine in the Treatment of Symptoms Of Acute Opioid Withdrawal

This Phase 1b/2 inpatient study assessed the safety, pharmacokinetics, and early signs of efficacy of escalating doses of BXCL501 versus placebo following discontinuation of morphine maintenance. The opioid (morphine) maintenance phase (Phase 1b) included Days 1-5; the randomized BXCL501/placebo phase (Phase 2) included Days 6-12. The randomized phase was followed by 2 sequential days, Days 13 and 14, utilizing treatment of BXCL501-placebo sublingual films and morphine-placebo capsules for all subjects who remained in the study.

Inclusion Criteria 1. Male and female subjects who are 18 years of age to less than 65 years of age. 2. Meets criteria for moderate to severe opioid use disorder as per Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria and confirmed by the Mini International Neuropsychiatric Interview (MINI) with physiological dependence as evidenced by a Clinical Opiate Withdrawal (COWS) score of \>5 or a positive naloxone challenge upon admission on Day 1. 3. Subjects who can read, understand, and provide written informed consent. Women of childbearing potential must have a negative pregnancy test and agree to be abstinent or use an acceptable method of contraception for the duration of the study. Exclusion Criteria 1. Positive urine pregnancy test at screening or when tested or currently breast feeding. 2. Clinically significant history of cardiac disease, screening and baseline heart rate of \2 x ULN. 6. Clinically significant abnormal ECG findings such as second- or third-degree heart block, uncontrolled arrhythmia, or QTcF (Fridericia correction formula) interval \>450 msec for males, and \>470 msec for females at screening or prior to dosing. 7. Any psychiatric disorder that would compromise ability to complete study requirements. 8. Currently meets DSM-5 criteria for substance abuse disorder, moderate or severe for any substance other than opioids, caffeine, or nicotine and/or current physical dependence on drugs that pose risk of withdrawal that requires medical management such as alcohol or benzodiazepines. 9. History of suicidal behavior within the last 1 year prior to screening. 10. Participation in a clinical trial of a non-FDA-approved pharmacological agent within 30 days prior to screening. 11. Use of any excluded medication at screening or anticipated/required use during the study period. 12. Subjects with a history of intolerance to morphine. 13. Any finding that, in the view of the principal investigator, would compromise the subject's ability to fulfill the protocol visit schedule or visit requirements.