Results From Sunobinop Phase 1B Study in Patients With Interstitial Cystitis/Bladder Pain Syndrome Announced

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STAMFORD, Conn.--(BUSINESS WIRE)--Sep 9, 2025--

Purdue Pharma L.P. (“Purdue”), announced positive preliminary results from a Phase 1b translational, signal detection clinical study evaluating the safety and efficacy of the investigational new chemical entity, sunobinop, in patients with interstitial cystitis/bladder pain syndrome (IC/BPS). IC/BPS is a chronic, painful, and debilitating urologic disorder that negatively affects patients’ quality of life and can lead to radical lifestyle and behavioral modifications. 1,2

At the end of the double-blind treatment period, those who received sunobinop reported a higher rate (41% versus 9%) of marked or moderate improvement compared to placebo in their overall IC/BPS symptoms, including reduced bladder pain, less need to urinate urgently, less need to urinate frequently, and larger volumes per void.

The study’s primary endpoint was change from baseline after 2-weeks and 6-weeks of treatment for eDiary bladder pain/discomfort scores (worst pain overnight and worst pain over the day) on an 11-point numerical rating scale (NRS), where 0 is “no bladder pain/discomfort,” and 10 is “as bad as you can imagine bladder pain/discomfort.” At completion of the 2-week and 6-week treatment period, a statistically significant reduction in NRS score from baseline of -0.7 (overnight) and -0.8 (over the day) and -1.6 (overnight) and -1.7 (over the day) was observed, respectively. Additional results from patient questionnaires, including the interstitial cystitis symptom index, further support a positive effect on symptoms during the sunobinop treatment period and were consistent with the study’s primary endpoint. The table below displays selected study results. Further evaluation of study results is ongoing.

NRS, Numerical Rating Scale; a lower score indicates less pain
ICSI, Interstitial Cystitis Symptom Index; A lower score indicates less severe disease
SD, standard deviation
Investigative sites and subjects were blinded to both the double-blind period eligibility criteria and the assignment of subjects to only a single treatment sequence

Sunobinop, a potential first-in-class oral compound, 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 involved in a range of biological functions. 3

“Patients with interstitial cystitis experience disruptive symptoms that can severely affect daily activities, work productivity, and overall quality of life. The findings from this study help us understand sunobinop’s potential as a possible new treatment option,” said Craig Landau, MD, President and CEO of Purdue. “We are encouraged by the findings from the study of sunobinop in these patients, which add to data we have collected in other bladder disorders.”

Forty-seven female patients diagnosed with IC/BPS were enrolled in this translational, signal detecting, multicenter, two period, single sequence, crossover study. The study was designed to assess the impact of once-a-day sunobinop and placebo taken at bedtime on key disease symptoms such as bladder pain and discomfort as well as urinary urgency and frequency.

The study included a single blind run-in phase (2-week placebo exposure), a double-blind treatment phase (2-weeks placebo followed by 6-weeks sunobinop exposure), and a safety follow-up phase (2 weeks duration). No deaths, serious adverse events, or discontinuation of sunobinop due to adverse events were reported. The most common adverse events observed in the study were urinary tract infection and somnolence.

“We are very pleased with the study results on this novel treatment approach”, said Julie Ducharme, BPharm, MSc, PhD, Vice President and Chief Scientific Officer. “Sunobinop has pharmacokinetic attributes that target the bladder and is the only orally administered NOP agonist being studied for this disorder.”

In addition to IC/BPS, Imbrium is evaluating sunobinop as a potential treatment for overactive bladder syndrome and separately for alcohol use disorder. All indications for sunobinop are open to partnering. For more information, email [email protected].

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 Purdue Pharma L.P.

Purdue Pharma and its subsidiaries develop, manufacture and market medications to meet the evolving needs of healthcare professionals, patients, and caregivers. Purdue and its subsidiaries focus on balancing innovative science with clinically effective, compassionate care. The Company’s goals are to serve patients who rely on its medicines, pursue public health initiatives intended to help abate the opioid crisis, advance its pipeline of branded and generic medications, and introduce medicines that will help save and improve lives.

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 www.imbriumthera.com.

References:

1. Lin KB-S, Wu M-P, Lin Y-K, et al. Lifestyle and behavioral modifications made by patients with interstitial cystitis. Sci Rep. 2021;11(1):3055.
2. Kirkham A, Swainston K. Women’s experiences of interstitial cystitis/painful bladder syndrome. West J Nurs Res. 2022;44(2):125-132.
3. Lambert, D. The nociceptin/orphanin FQ receptor: a target with broad therapeutic potential. Nat. Rev. 2008;7(8):694-710.

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SOURCE: Imbrium Therapeutics L.P.

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PUB: 09/09/2025 09:00 AM/DISC: 09/09/2025 08:59 AM

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