December 12, 2022 Press Release

Imbrium Therapeutics Presents Results of a Phase 2 Study of Sunobinop at 33rd American Academy of Addiction Psychiatry Annual Meeting

Data demonstrate positive preliminary results for sunobinop as a potential first-in-class treatment for insomnia during recovery from alcohol use disorder*

STAMFORD, Conn. – December 12, 2022 – Imbrium Therapeutics L.P. (“Imbrium”), a subsidiary of Purdue Pharma L.P. (“Purdue”), today announced preliminary results from a Phase 2 clinical study evaluating the safety and efficacy of the novel investigational treatment sunobinop (IMB-115 / V117957) in patients experiencing insomnia during recovery from alcohol use disorder (AUD). The data were presented in a poster presentation (#76) at the 33rd Annual Meeting and Scientific Symposium of the American Academy of Addiction Psychiatry (AAAP).

Sunobinop is an internally discovered oral compound being evaluated as a potential treatment for multiple disorders including insomnia during recovery from AUD. The mechanism of action is designed to bind to and activate the nociceptin/orphanin-FQ peptide receptor (NOP), a protein that is widely expressed in the central and peripheral nervous system and is involved in a range of biological functions including modulation of anxiety, response to stress and substance abuse.1,2 

While results from clinical studies vary, the prevalence of sleep disturbances in people recovering from AUD range from 69% to as high as 91% during the early phase of withdrawal.3,4 These individuals often experience changes in sleep latency, maintenance, and architecture, characterized by more time spent in the initial stages of sleep, more awakenings, and reduced total sleep time.5 These symptoms can often persist for years following alcohol cessation5 and studies of patients with AUD have found untreated insomnia may interfere with recovery from alcohol addiction and contribute to relapse.6 

“Our research program with sunobinop, and specifically results from this Phase 2 clinical study, underscore our commitment to advancing medicines that may benefit patients who are in recovery,” said Dr. Julie Ducharme, Vice President, Chief Scientific Officer.

The Phase 2 randomized, double-blind, multi-center, placebo-controlled, parallel-group clinical study enrolled 114 people experiencing insomnia during recovery from AUD. Patients were randomly assigned in a 1:1:1 ratio to receive sunobinop 1 mg or 2 mg or placebo every night at bedtime for 21 days, and 89% of patients completed the study. The primary endpoint was change from baseline on wakefulness after sleep onset (WASO; or the time spent awake after falling asleep), as measured by two consecutive nights of overnight polysomnography (PSG) assessed on nights 1 and 2 and at on nights 20 and 21 of dosing.

Results demonstrate both doses of sunobinop met the primary endpoint, with significant and clinically meaningful reductions in WASO, compared with placebo, that were maintained across the 3 weeks of dosing in the study. On nights 1/2, the least squares mean (LSM) difference between sunobinop 1 mg and placebo was −12.03 minutes (95% CI, −22.1 to −1.9; P=0.050), and the LSM difference between sunobinop 2 mg and placebo was −18.35 minutes (95% CI, −28.5, −8.2; P=0.003). On nights 20/21, the LSM difference between sunobinop 1 mg and placebo was −12.35 minutes (CI, −24.7 to 0.0; P=0.099), and the LSM difference between sunobinop 2 mg and placebo was −15.80 minutes (CI, −28.6, −3.0; P=0.043). Impact on sleep was also demonstrated for several secondary endpoints as measured by polysomnography while effects on subjective sleep measures collected did not reach statistical significance.

Sunobinop was well tolerated across both doses. No serious adverse events were reported. One patient receiving sunobinop 2 mg discontinued due to sedation. All treatment-emergent adverse events (TEAEs) were mild or moderate. The most common TEAE was somnolence (or drowsiness), which was reported in 5% of the sunobinop 1 mg group and 26% of the sunobinop 2 mg group. Baseline alcohol craving scores as assessed via the Penn Alcohol Craving Scale (PACS) were low with no increase in craving observed in any treatment group. 

“Currently, there are no FDA-approved products specifically indicated for insomnia during recovery from AUD. We appreciate the opportunity to present our findings at AAAP from this Phase 2 study of sunobinop in patients diagnosed with alcohol use disorder experiencing insomnia during self-reported abstinence from alcohol.” said Nelson Sessler, PharmD, lead author on the study.

Sunobinop is currently in clinical development for multiple indications including, Insomnia During Recovery from AUD, Overactive Bladder and Interstitial Cystitis/Bladder Pain Syndrome.

*This press release discusses investigational uses of an agent in development and is not intended to convey conclusions about efficacy or safety. There is no guarantee that sunobinop will successfully complete development or gain FDA approval.


About Imbrium Therapeutics L.P.

Imbrium is a clinical-stage biopharmaceutical company dedicated to advancing medical science through the development of important new pharmacologic and biologic therapeutics. We are pursuing oncology chemotherapeutics, treatments for disorders of the central nervous system, and non-opioid approaches to the management of pain. As a subsidiary of Purdue Pharma L.P., Imbrium strives to develop and bring to market new medicines that serve the unmet needs of patients, physicians and health systems worldwide. We have built a robust and diversified pipeline of investigational drug candidates, and we actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit

Media Contact:

Michele Sharp

(203) 588-7584


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