A Randomized, Controlled Study of Repeat Dose Sustained Release Lidocaine for Treatment of Chronic Scrotal Pain

A Randomized, Controlled Phase II Study of Repeat Dose ST-01 (Lidocaine Polymer Solution) vs Lidocaine for Spermatic Cord Block in Men With Chronic Scrotal Content Pain

This multi-center, phase 2, randomized, single-blind, three-arm, active-controlled study is comparing repeat doses, every 28 days, of standard of care (SOC) plus ST-01 against SOC plus 1% lidocaine HCL in men experiencing chronic scrotal content pain (CSCP). The main purpose of this study is to determine if repeat injections of ST-01 are safe and effective in reducing pain. After completing a screening phase participants will be randomized into one of three groups: 1) ST-01 70 mg/mL arm, 2) ST-01 140 mg/mL arm, 3) 1% Lidocaine HCL arm (Control). Participants may receive up to 4 study treatment injections given at a minimum of 28-day intervals. Participants randomized to the Control arm will be given the opportunity to cross over to an ST-01 treatment arm after 2 study treatments.

Study Overview

• Status: Completed
• Conditions: Chronic Pain
• Intervention / Treatment: Drug: ST-01; Drug: 1% Lidocaine HCL

• Study Type: Interventional
• Enrollment (Actual): 63
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2V 1P9
      • Prostate Cancer Centre - Rockyview Hospital
  • British Columbia
    • Kelowna, British Columbia, Canada, V1Y 1T2
      • Kelowna General Hospital Clinical Research Department
    • Vancouver, British Columbia, Canada, V5Z 1M9
      • Vancouver Prostate Centre
  • Manitoba
    • Winnipeg, Manitoba, Canada, R3P 2S8
      • Men's Health Clinic Manitoba
  • Ontario
    • Brampton, Ontario, Canada, L6T 4S5
      • Jonathan Giddens Medicine Professional Corporation
    • Oakville, Ontario, Canada, L6H 3P1
      • The Fe/Male Health Centre
    • Toronto, Ontario, Canada, M5T 3L9
      • Mount Sinai Hospital - Men's Health Institute
  • Quebec
    • Montreal, Quebec, Canada, H3M 1L3
      • THEO Medical

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Adult (≥ 19 years) male
2. Unilateral or bilateral scrotal pain lasting > 3 months
3. Have nociceptive scrotal pain
4. Average daily maximum scrotal pain score over 7 days ≥ 4 on the 0-10 NRS (Appendix 2). Participants with bilateral scrotal pain must be able to distinguish one side with pain score ≥ 4 and the opposite side must have a maximum scrotal pain score of ≤ 3.0 at baseline.
5. Positive response to test spermatic cord block with 1% lidocaine (Lidocaine Hydrochloride Injection, USP, 1%, 10 mg/mL), defined as a decrease in pain score of at least 2 within 1 hour of injection
6. Baseline blood levels without clinically significant abnormalities including liver function tests (alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], and alkaline phosphatase [ALP]) no greater than 50% above the upper limit of normal
7. If sexually active, is willing to use adequate birth control methods to prevent pregnancy over the course of the study

Exclusion Criteria:

1. Negative response to test spermatic cord block, defined as absence of a decrease in pain score of at least 2 within an hour of injection
2. Other pain generator site with NRS pain score ≥ 4 that interferes with evaluation of scrotal pain
3. History of allergic reaction to lidocaine or any component of ST-01
4. Any contraindication to local anesthesia with lidocaine (e.g., known hypersensitivity to anesthetics of the amide type; hypokalemia, complete heart block, anticoagulants (aspirin permitted), antiarrhythmic medication.)
5. Active infection involving the urinary tract or scrotum
6. Inability to give consent
7. Inability to follow up according to the protocol
8. Negative response to previous spermatic cord block
9. Any other condition that the investigator believes may interfere with the safety of the participant, study conduct, or interpretation of the data.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ST-01 70 mg/mL	Drug: ST-01; A sustained release lidocaine formulation designed for the treatment of acute and chronic pain.
Experimental: ST-01 140 mg/mL	Drug: ST-01; A sustained release lidocaine formulation designed for the treatment of acute and chronic pain.
Active Comparator: 1% Lidocaine HCL	Drug: 1% Lidocaine HCL; Currently approved lidocaine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Pain Scores on the Numerical Rating Scale (NRS) at 56 days.	To evaluate the change of pain score from baseline to day 56 in the active treatment cohorts (after 1 or 2 injections of ST-01) and compare to the standard of care control group. Pain score being used is the participant reported NRS scale (measured from 0-10 where 0 is no pain and 10 is maximum pain.)	28 days after the second injection of ST-01 or 56 days after the first injection if only one study injection is received.

Collaborators and Investigators

• Sponsor: Sustained Therapeutics Inc.
• Investigators: Study Director: Graeme Boniface, PhD., Sustained Therapeutics Inc.

Study record dates

Study Major Dates

• Study Start (Actual): March 21, 2023
• Primary Completion (Actual): December 4, 2025
• Study Completion (Actual): January 21, 2026

Study Registration Dates

• First Submitted: January 20, 2023
• First Submitted That Met QC Criteria: January 27, 2023
• First Posted (Actual): January 31, 2023

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Chronic testicular pain; Orchialgia; Chronic Scrotal Content Pain; Chronic scrotal pain; spermatic cord
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Chronic Pain; Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Lidocaine
• Other Study ID Numbers: ST-CP-202

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No