Sustained Therapeutics, Inc. has presented additional data from its phase 2 study evaluating ST-01, a proprietary non-opioid sustained-release small molecule therapy, in men with chronic scrotal content pain (CSCP).
The data were presented in an oral podium presentation at the American Urological Association (AUA) 2026 annual meeting in Washington, DC by lead investigator, Ryan K Flannigan, associate professor at the Department of Urologic Sciences, University of British Columbia and director of the Male Reproductive and Sexual Medicine Research Program and fellowship director for male reproductive medicine, sexual medicine and microsurgery.
In the randomised phase 2 study, ST-01 demonstrated statistically significant improvements in pain reduction and clinical response rates at the 70 mg/mL dose compared to standard of care alone. The treatment was generally well tolerated, and responses were shown to be durable over repeated dosing cycles.
“Chronic scrotal content pain remains a challenging and underrecognized condition in urology with many patients cycling through therapies that provide only temporary relief,” Flannigan said.
“The safety and efficacy signals observed in this study are highly encouraging and support continued evaluation of ST-01 as a potential new therapeutic option for these patients. Our hope is that this work may ultimately lead to a transformative, non-surgical treatment approach for men living with chronic scrotal pain, pending additional studies to validate these findings.”
“These results reinforce the growing excitement within the urology community around the potential for a non-opioid treatment option for chronic urologic pain,” said William Annett, CEO of Sustained Therapeutics.
“We believe ST-01 has the potential to transform care for patients while also delivering meaningful value for physicians and their patients as well as seeking alternatives to repeated procedures, chronic opioid use, and invasive surgery.”
The randomised, multi-centre, single-blind, active-controlled phase 2 study enrolled 63 men across eight clinical sites in Canada evaluating repeat monthly dosing of ST-01 in CSCP. The study compared ST-01 to standard-of-care spermatic cord block with lidocaine alone (control).
At the 70 mg/mL dose, ST-01 demonstrated statistically significant improvements in both the primary and secondary efficacy endpoints compared to control.
The study found that 67% of patients treated with ST-01 70 mg/mL achieved a treatment response, defined as a ≥2-point reduction in pain scores, compared to 26% in the control arm, while 83% of patients receiving ST-01 70 mg/mL achieved a clinical response based on cycle-average pain scores, compared to 32% in the control arm.
Patients who crossed over from control treatment to ST-01 achieved >80% response further supporting the therapeutic effect of ST-01
The company believes the findings support continued development of ST-01 as a potential non-opioid treatment option for CSCP and plans to advance the programme toward phase 3 development, subject to regulatory review.
Chronic scrotal content pain is a debilitating condition affecting an estimated 5m men in North America with approximately 700,000 new cases diagnosed annually. Current treatment options are limited and often inconsistent, ranging from oral analgesics and opioids to invasive surgical procedures. Sustained Therapeutics believes ST-01 has the potential to address a significant unmet need as a targeted, non-opioid therapy designed to provide durable localized pain relief.
Beyond chronic scrotal content pain, the company believes its sustained-release platform may have broader applicability across additional chronic pain indications, including chronic pelvic pain, a condition affecting an estimated 13m men and women in North America with few effective long-term treatment options. Sustained Therapeutics plans to evaluate ST-01 in chronic pelvic pain in future clinical studies.
According to market research conducted by the company, approximately 80% of urologists surveyed identified chronic urologic pain as a significant unmet need in clinical practice. Sustained Therapeutics believes ST-01’s targeted, office-based administration and non-opioid profile may provide meaningful benefits across the healthcare ecosystem including improved quality of life for patients, an easy-to-administer therapeutic option for physicians, and the potential to reduce downstream healthcare costs associated with repeat procedures, opioid utilisation, and surgery.