July 9, 2024 Press Release

Imbrium Therapeutics Achieves Last Patient Last Visit in Clinical Trial of Potential Treatment for Overactive Bladder Syndrome

STAMFORD, Conn., July 9, 2024 – Imbrium Therapeutics L.P. (“Imbrium”), a subsidiary of Purdue Pharma L.P. (“Purdue”), achieved last patient last visit in its Phase 1b study of the investigational drug sunobinop as a potential treatment for overactive bladder syndrome (OAB)*.

Sunobinop is an investigational, novel and potential first-in-class oral compound discovered by Imbrium Therapeutics and that is currently in clinical development. Sunobinop 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 system1 and involved in a range of biological functions, including bladder function.2,3

Fifty-one female patients suffering from OAB were enrolled in this multicenter, randomized, double-blind, placebo-controlled crossover study. The study was designed to test the effects of sunobinop at bedtime on key disease symptoms, such as urinary urgency, frequency, incontinence, and nocturia in subjects with OAB compared to placebo. OAB is a life-long urologic disorder that reduces patients’ quality of life. The condition affects 14% of men and women in the U.S. 4

“Millions of patients with overactive bladder are in need of additional treatment options for the disruptive, distressing symptoms. This study will help us learn more about sunobinop’s potential to be a new treatment option,” said Dr. Julie Ducharme, Vice President and Chief Scientific Officer. “We look forward to reviewing and analyzing the results later this year.”

“We are pleased to achieve last patient last visit in the sunobinop Phase 1b study,” said Craig Landau, MD, President and CEO of Purdue. “Our continued progress in this work demonstrates our ongoing commitment to innovation through research and development.”

In addition to OAB, Imbrium is also evaluating sunobinop as a potential treatment for interstitial cystitis/bladder pain syndrome (IC/BPS) and separately for alcohol use disorder.

*This 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 therapeutics. We are pursuing treatments for genitourinary disorders, disorders of the central nervous system, oncology chemotherapeutics, and non-opioid approaches to the management of pain. As a subsidiary of Purdue Pharma L.P., Imbrium strives to develop 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 seek to actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit

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  1. Zaveri, N. The nociceptin opioid receptor (NOP) as a therapeutic target: Progress in translation from preclinical research to clinical utility. J Med Chem. 2016; 59(15): 7011-7028.
  2. Lambert, D. The nociception/orphanin FQ receptor: a target with broad therapeutic potential. Nat. Rev. 2008;7(8):694-710.
  3. Lazzeri, M., Calò, G., Spinelli, M., et al. Daily intravesical instillation of 1 mg nociceptin/orphanin FQ for the control of neurogenic detrusor overactivity: a multicenter, placebo controlled, randomized exploratory study. J Urol. 2006;176(5):2098-102.
  4. Reynolds, W., Fowke, J., & Dmochowski, R. The burden of overactive bladder on US public health. Current Bladder Dysfunct Rep. 2016;11(1):8–13.