Sustained Therapeutics Highlights Positive Mid-Stage Clinical Outcomes for Its Investigational Therapy ST-01
Sustained Therapeutics has reported additional positive findings from its Phase 2 clinical study evaluating ST-01, the company’s proprietary non-opioid sustained-release therapy for men suffering from chronic scrotal content pain (CSCP), a condition that continues to present major treatment challenges in urology. The new data were presented during the American Urological Association Annual Meeting 2026 in Washington, DC, highlighting growing interest in alternative therapies for chronic urologic pain conditions that currently have limited effective treatment options.
The oral podium presentation was delivered by Ryan K Flannigan, Associate Professor in the Department of Urologic Sciences at the University of British Columbia. Dr. Flannigan also serves as Director of the Male Reproductive and Sexual Medicine Research Program and Fellowship Director for Male Reproductive Medicine, Sexual Medicine, and Microsurgery.
The study results demonstrated that ST-01 achieved statistically significant improvements in pain reduction and treatment response rates compared with standard-of-care therapy alone, particularly at the 70 mg/mL dose level. According to the company, the therapy was generally well tolerated and produced durable responses across repeated dosing cycles, supporting continued development of the treatment candidate.
Chronic scrotal content pain is a long-term and often debilitating condition characterized by persistent pain in the scrotal region. The disorder can severely affect quality of life, physical activity, mental health, sexual function, and daily functioning. Despite the significant impact on patients, treatment options remain limited, and many individuals cycle through multiple therapies with inconsistent or temporary relief.
Dr. Flannigan noted during the presentation that CSCP remains an underrecognized and difficult-to-manage condition within urology. He explained that patients frequently undergo repeated therapies, including oral pain medications, nerve blocks, and surgical interventions, without achieving long-lasting symptom control.
According to Dr. Flannigan, the safety and efficacy signals observed in the Phase 2 study are encouraging and support additional clinical evaluation of ST-01 as a potential therapeutic alternative for patients with chronic scrotal pain. He added that the research could ultimately contribute to the development of a transformative non-surgical treatment strategy for men living with the condition, pending further validation in larger studies.
The study findings were presented during Podium Session PD26: Sexual Function/Dysfunction – Medical, Hormonal & Non-surgical Therapy II under Abstract PD26-15, titled “A Randomized Phase 2 Study of Repeat Dose ST-01 (Lidocaine Polymer Solution) vs Lidocaine for Spermatic Cord Block in Men with Chronic Scrotal Content Pain.”
William Annett, Chief Executive Officer of Sustained Therapeutics, said the new results reinforce growing enthusiasm within the urology field regarding the possibility of a non-opioid therapeutic option for chronic urologic pain conditions.
Annett stated that the company believes ST-01 could significantly improve patient care by offering an alternative to chronic opioid therapy, repeated interventional procedures, and invasive surgeries. He emphasized that physicians and patients alike are seeking safer and more durable treatment options capable of delivering meaningful pain relief without the complications associated with long-term opioid use or surgical intervention.
The randomized, multi-center, single-blind, active-controlled Phase 2 study enrolled 63 male patients across eight clinical centers in Canada. The trial evaluated repeat monthly dosing of ST-01 in patients diagnosed with chronic scrotal content pain. Participants receiving ST-01 were compared with patients receiving standard-of-care spermatic cord block procedures using lidocaine alone.
The company reported that the 70 mg/mL dose of ST-01 met both primary and secondary efficacy endpoints with statistically significant improvements compared with the control group.
Among the most notable findings, 67% of patients treated with ST-01 at the 70 mg/mL dose achieved a treatment response defined as at least a two-point reduction in pain scores. By comparison, only 26% of patients in the control arm achieved the same response threshold. The difference between the two groups reached statistical significance with a p-value of 0.01.
Additionally, 83% of patients receiving ST-01 achieved a clinical response based on cycle-average pain scores compared with 32% of patients treated with standard therapy alone. This result also demonstrated strong statistical significance, with a reported p-value of 0.001.
The study also included crossover observations in which patients initially treated with control therapy later received ST-01. According to the company, more than 80% of these crossover patients achieved treatment responses after transitioning to ST-01 therapy, further supporting the therapeutic potential of the sustained-release treatment platform.
Sustained Therapeutics stated that the positive findings strengthen its confidence in advancing ST-01 into later-stage clinical development. The company plans to move the program toward Phase 3 evaluation pending ongoing regulatory review and discussions with health authorities.
CSCP represents a significant unmet medical need affecting an estimated five million men across North America, with approximately 700,000 new cases diagnosed each year. Current treatment approaches vary widely and often fail to provide durable symptom control. Many patients rely on oral analgesics, anti-inflammatory drugs, opioids, nerve block procedures, or surgery, each of which carries limitations related to efficacy, tolerability, or invasiveness.
The company believes ST-01 may provide a differentiated therapeutic approach by delivering localized, sustained-release pain control through a targeted administration method. Because the therapy is non-opioid in nature, it may also help reduce reliance on opioid medications, which remain associated with risks including dependency, misuse, and long-term adverse effects.
Beyond its potential role in chronic scrotal content pain, Sustained Therapeutics believes its sustained-release drug delivery platform may be applicable across a broader range of chronic pain conditions. One area of future interest is chronic pelvic pain, another difficult-to-treat disorder affecting an estimated 13 million men and women throughout North America.
The company indicated that future clinical studies may explore the use of ST-01 in chronic pelvic pain populations as part of broader efforts to expand the platform’s therapeutic applications.
Sustained Therapeutics also referenced internal market research suggesting that approximately 80% of surveyed urologists identified chronic urologic pain as a major unmet need in clinical practice. According to the company, physicians continue to seek office-based therapies that can be administered efficiently while reducing the burden associated with repeat procedures and escalating treatment intensity.
The company believes ST-01’s profile as a targeted, office-based, non-opioid therapy could create meaningful advantages across the healthcare system. Potential benefits may include improved quality of life for patients, easier treatment administration for healthcare providers, and reductions in downstream healthcare expenditures associated with surgery, repeated interventions, and long-term opioid use.
As awareness of chronic urologic pain disorders continues to increase, the Phase 2 findings presented at the American Urological Association meeting position ST-01 as a potentially important investigational therapy in an area where few durable treatment options currently exist. With plans underway to advance into Phase 3 development, Sustained Therapeutics is seeking to establish ST-01 as a new therapeutic alternative for patients affected by chronic pain conditions that have historically been difficult to manage effectively.
About Sustained Therapeutics:
Sustained Therapeutics is a clinical-stage urology company developing differentiated therapeutics for underserved urologic conditions. Founded by leading urologists and scientists from the University of British Columbia and the Vancouver Prostate Centre, the Company is advancing a pipeline of urology products designed to provide durable, localized treatment while minimizing systemic exposure.
The Company’s lead program, ST-01, is an investigational therapy for chronic urologic pain, including chronic scrotal content pain and chronic pelvic pain. Sustained Therapeutics’ proprietary, patent-protected drug delivery platform is also being developed across additional urologic indications, including oncology, erectile dysfunction, female sexual dysfunction, and fibrotic diseases.
Sustained Therapeutics is focused on transforming care in urology through targeted therapies that address significant unmet clinical needs while improving outcomes for patients, physicians, and healthcare systems.
