Efficacy of Methylene Blue Photodynamic Therapy for Treatment of Deep Tissue Abscesses

NCT ID: NCT06052956

Last Updated: 2025-08-11

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: PHASE2
• Total Enrollment: 120 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-12-15
• Study Completion Date: 2030-11-15

Brief Summary

The objective of this Phase 2 study is to evaluate the efficacy of methylene blue photodynamic therapy (MB-PDT) performed at the time of percutaneous abscess drainage for disinfection of deep tissue abscesses. The study includes three arms: (1) MB-PDT at a fixed drug/light dose plus standard of care abscess drainage , (2) MB-PDT at a patient-specific dose determined by pre-treatment optical measurements plus standard of care abscess drainage , and (3) standard of care abscess drainage. The primary endpoint is reduction in time to removal of the drainage catheter.

Detailed Description

Abscesses form as a result of the interaction between an acute microbial infection and the host immune system, and generally result in fever, nausea, and acute abdominal pain. If untreated, the mortality rate can be high. Abscesses are routinely managed by image-guided percutaneous drainage and delivery of systemic antibiotics. Despite this standard of care, abscesses remain a significant source of morbidity, mortality, and hospital stay. Further, response can vary widely between patients. Many abscesses also contain antibiotic resistant species.

Photodynamic therapy (PDT), which relies upon the combination of photosensitive dyes known as photosensitizers, excitation by visible light, and molecular oxygen to generate cytotoxic reactive oxygen species, represents a powerful adjunct to standard of care drainage. A Phase 1 clinical trial aimed at assessing the safety and feasibility of methylene blue (MB) PDT at the time of percutaneous abscess drainage (ClinicalTrials.gov Identifier: NCT02240498) was completed. No adverse or serious adverse events were observed, and the procedure was well tolerated by all subjects. Based on these encouraging Phase 1 results, the current study therefore aims to assess efficacy of MB-PDT by quantification of time to removal of the drainage catheter and microbiological analysis of pre- and post-PDT aspirate samples.

This is a single center, randomized, open-label Phase 2 clinical trial, which will be conducted in accordance with the principles of good clinical practice and following approval by both the FDA and local IRB. Patients who have been diagnosed with a drainable abscess, that meet all inclusion/exclusion criteria, and have the approval of their primary care team, will be offered enrollment in the study. Consented subjects will be assigned prospectively to one of three arms: (1) MB-PDT at a fixed drug/light dose plus standard of care abscess drainage, (2) MB-PDT at a patient-specific dose determined by pre-treatment optical measurements plus standard of care abscess drainage, and (3) standard of care abscess drainage alone. The primary endpoint is time to removal of the drainage catheter. The secondary endpoint is reduction in bacterial burden from pre- to post-intervention. Tertiary endpoints include drain output following intervention, resolution of clinical symptoms, abscess recurrence, need for repeated intervention, and cure rate.

All subjects will receive standard of care image-guided percutaneous abscess drainage. This includes collection of a pre-intervention abscess aspirate sample, and placement of a drainage catheter.

For subjects in Arms 1 and 2, sterile methylene blue (MB) will then be administered to the abscess cavity using the same needle/catheter utilized for standard of care drainage. After a 10 minute incubation interval, MB will be aspirated and the cavity flushed with sterile saline.

For subjects in Arm 2, optical spectroscopy measurements will then be made to determine the optical properties of the abscess wall. This will be done by connecting the proximal end of the sterile optical fiber used for treatment illumination to a custom optical spectroscopy system. The distal end of this fiber will be advanced through the same catheter/needle used for the standard of care procedure in order to make gentle contact with the wall of the cavity. Low-intensity white light will be delivered by the fiber, and light that has interacted with the abscess wall will be detected by the same optical fiber. These optical measurements will be averaged and used to extract the absorption and reduced scattering coefficients at the treatment wavelength. These extracted optical properties, along with the subject's segmented pre-procedure CT images, will be used to generate a patient-specific treatment plan that seeks to deliver a desired fluence rate to 95% of the abscess wall, while limiting the portion of the abscess wall that receives a high fluence rate (>400 mW/cm2) to less than 5%.

For subjects in Groups 1 and 2, the cavity will then be filled with sterile 0.1% lipid emulsion solution to gently distend the cavity, and through efficient light scattering, homogenize the light dose to the walls of the cavity. A sterile optical fiber will be advanced to the approximate center of the abscess cavity via the same catheter/needle under image guidance. The proximal end of the fiber is coupled to the output of a diode laser system emitting light at 665 nm.

For subjects in Group 1 (MB-PDT at a fixed dose), laser power will be delivered to the cavity at a constant fluence rate. The laser power required to obtain the desired fluence rate at the wall will be calculated purely based on the abscess size. For subjects in Group 2 (MB-PDT with patient-specific treatment planning), the subject's measured optical properties and their segmented pre-procedure CT images will be integrated with treatment planning software to determine the laser power required to deliver the desired fluence rate to 95% of the abscess wall, while limiting the portion of the abscess wall that receives a fluence rate of >400 mW/cm2 to less than 5%. In both cases, illumination will be delivered for 20 minutes, resulting in a total delivered fluence of 24 J/cm2. Immediately after laser irradiation, the Intralipid solution will be aspirated and the cavity again flushed with sterile saline.

Collection of aspirated abscess material for microbiological assessment is standard of care for percutaneous abscess drainage. A portion of this standard of care collection will be collected by the study team for additional quantitative evaluation. Additionally, a post-intervention aspirate sample will be collected for study purposes.

If successful, this research could result in an adjunct treatment for abscess patients that improves long-term abscess resolution and the rate of response to percutaneous drainage. This clinical strategy would offer a wide range of potential health benefits to patients with deep tissue abscess. Among these advantages are reduced surgical intervention, decreased spread of infection, shortened course of post-treatment antibiotic therapy, and decreased selective pressure for antibiotic resistance. Ultimately, this would promote early recovery, shorten hospital stay, and lead to lower overall health care costs for patients undergoing image-guided percutaneous abscess drainage.

Conditions

Abscess

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

MB-PDT at pre-defined dose plus standard of care abscess drainage

Each subject in this arm will receive standard of care abscess drainage, methylene blue, lipid emulsion, and laser illumination at an optical power defined by their abscess size.

Group Type: EXPERIMENTAL

Methylene Blue

Intervention Type: DRUG

Administration of 0.1 mg/mL methylene blue to the abscess cavity, followed by a 10 minute incubation interval. After this incubation interval, the methylene blue solution will be aspirated from the cavity and flushed twice with sterile saline.

Lipid Emulsion

Intervention Type: DRUG

The abscess cavity will be filled with sterile 0.1% lipid emulsion solution to gently distend the cavity and, through efficient light scattering, to homogenize the light dose to the walls of the cavity. After laser illumination, the Intralipid will be aspirated from the cavity.

Insertion of optical fiber

Intervention Type: DEVICE

A sterile, FDA-approved optical fiber will be advanced to the approximate center of the abscess cavity via the drainage catheter under image guidance. Following laser illumination, the fiber will be withdrawn.

Laser Illumination (pre-defined dose)

Intervention Type: DEVICE

Laser illumination will be delivered via the optical fiber for a duration of 20 minutes. The optical power will be set such that the fluence rate at the abscess wall due to ballistic photons is 20 mW/cm2.

Standard of care abscess drainage

Intervention Type: PROCEDURE

Following standard practice, a drainage catheter will be placed in the abscess cavity and used to aspirate purulent fluid.

MB-PDT at patient-specific dose plus standard of care abscess drainage

Each subject in this arm will receive standard of care abscess drainage, methylene blue, lipid emulsion, optical spectroscopy, and laser illumination. The optical power for laser illumination will be determined by their abscess morphology and the results of optical spectroscopy.

Group Type: EXPERIMENTAL

Methylene Blue

Intervention Type: DRUG

Administration of 0.1 mg/mL methylene blue to the abscess cavity, followed by a 10 minute incubation interval. After this incubation interval, the methylene blue solution will be aspirated from the cavity and flushed twice with sterile saline.

Lipid Emulsion

Intervention Type: DRUG

The abscess cavity will be filled with sterile 0.1% lipid emulsion solution to gently distend the cavity and, through efficient light scattering, to homogenize the light dose to the walls of the cavity. After laser illumination, the Intralipid will be aspirated from the cavity.

Insertion of optical fiber

Intervention Type: DEVICE

A sterile, FDA-approved optical fiber will be advanced to the approximate center of the abscess cavity via the drainage catheter under image guidance. Following laser illumination, the fiber will be withdrawn.

Optical Spectroscopy Measurement

Intervention Type: DEVICE

The same sterile optical fiber used for treatment will be advanced through the drainage catheter/needle in order to make gentle contact with the wall of the cavity. Low-intensity, polarized white light will be delivered by a tungsten halogen lamp by the fiber, and captured by the same fiber. Light that has been de-polarized by interaction with tissue will be detected by a spectrometer and analyzed to extract tissue optical properties. Upon completion of these measurements, the fiber optic will be withdrawn, gently wiped with sterile gauze, and returned to the procedure cart.

Laser Illumination (patient-specific dose)

Intervention Type: DEVICE

Laser illumination will be delivered via the optical fiber for a duration of 20 minutes. The optical power will be set to deliver a fluence rate of 20 mW/cm2 in 95% of the abscess wall, based upon abscess morphology and optical spectroscopy results.

Standard of care abscess drainage

Intervention Type: PROCEDURE

Following standard practice, a drainage catheter will be placed in the abscess cavity and used to aspirate purulent fluid.

Standard of care abscess drainage

Each subject in this arm will receive standard of care abscess drainage

Group Type: OTHER

Standard of care abscess drainage

Intervention Type: PROCEDURE

Following standard practice, a drainage catheter will be placed in the abscess cavity and used to aspirate purulent fluid.

Interventions

Methylene Blue

Administration of 0.1 mg/mL methylene blue to the abscess cavity, followed by a 10 minute incubation interval. After this incubation interval, the methylene blue solution will be aspirated from the cavity and flushed twice with sterile saline.

Intervention Type: DRUG

Lipid Emulsion

The abscess cavity will be filled with sterile 0.1% lipid emulsion solution to gently distend the cavity and, through efficient light scattering, to homogenize the light dose to the walls of the cavity. After laser illumination, the Intralipid will be aspirated from the cavity.

Intervention Type: DRUG

Insertion of optical fiber

A sterile, FDA-approved optical fiber will be advanced to the approximate center of the abscess cavity via the drainage catheter under image guidance. Following laser illumination, the fiber will be withdrawn.

Intervention Type: DEVICE

Laser Illumination (pre-defined dose)

Laser illumination will be delivered via the optical fiber for a duration of 20 minutes. The optical power will be set such that the fluence rate at the abscess wall due to ballistic photons is 20 mW/cm2.

Intervention Type: DEVICE

Optical Spectroscopy Measurement

The same sterile optical fiber used for treatment will be advanced through the drainage catheter/needle in order to make gentle contact with the wall of the cavity. Low-intensity, polarized white light will be delivered by a tungsten halogen lamp by the fiber, and captured by the same fiber. Light that has been de-polarized by interaction with tissue will be detected by a spectrometer and analyzed to extract tissue optical properties. Upon completion of these measurements, the fiber optic will be withdrawn, gently wiped with sterile gauze, and returned to the procedure cart.

Intervention Type: DEVICE

Laser Illumination (patient-specific dose)

Laser illumination will be delivered via the optical fiber for a duration of 20 minutes. The optical power will be set to deliver a fluence rate of 20 mW/cm2 in 95% of the abscess wall, based upon abscess morphology and optical spectroscopy results.

Intervention Type: DEVICE

Standard of care abscess drainage

Following standard practice, a drainage catheter will be placed in the abscess cavity and used to aspirate purulent fluid.

Intervention Type: PROCEDURE

Other Intervention Names

Methylene Blue Injection, 1%; Intralipid 20%; Nutrilipid 20%; Boston Scientific Flexiva Pulse ID; Modulight ML7710 Laser System; Modulight ML7710 Laser System; Image-guided percutaneous drainage

Eligibility Criteria

Inclusion Criteria

• Adults 18 years or older
• All patients with clinical symptoms (ex: fever, chills, pain, tachycardia, hypotension), laboratory (leukocytosis) and radiologic findings (thick walled, rim-enhancing collection with gas bubbles or air-fluid levels) compatible with an abscess that requires image- guided percutaneous drainage
• Approval by the primary care team to pursue PDT and discuss enrollment with the patient

Exclusion Criteria

• Pregnancy
• Lactation
• Allergy to contrast media, narcotics, sedatives, atropine or eggs
• Necrotic tissue that requires surgical debridement
• Severely compromised cardiopulmonary function or hemodynamic instability
• Thrombocytopenia (<50,000/mm3)
• Uncorrectable coagulopathy
• Poor kidney function (serum creatinine >3mg/dl)
• Lack of a safe pathway to the abscess or fluid collection
• Unable or unwilling to understand or to provide informed consent
• Unable or unwilling to undergo study procedures
• Patient unable to cooperate with, or to be positioned for the procedure
• Unable to comply with necessary follow up
• Patients with pancreatic abscesses
• Patients with known fistulous communication with their abscess
• Abscess greater than 13 cm in diameter

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Rochester

OTHER

Sponsor Role: lead

Responsible Party

Timothy Baran

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Timothy M Baran, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Rochester

Ashwani K Sharma, MD

Role: PRINCIPAL_INVESTIGATOR

University of Rochester

Laurie Christensen, BS

Role: STUDY_DIRECTOR

University of Rochester

Locations

Highland Hospital

Rochester, New York, United States

University of Rochester Medical Center

Rochester, New York, United States

Countries

United States

Central Contacts

Timothy M Baran, PhD

Role: CONTACT

Timothy_Baran@URMC.Rochester.edu

585-276-3188

Ashwani K Sharma, MD

Role: CONTACT

Ashwani_Sharma@URMC.Rochester.edu

585-276-5491

Facility Contacts

Timothy M Baran, PhD

Role: primary

Timothy_Baran@URMC.Rochester.edu

585-276-3188

Laurie Christensen, BS

Role: backup

Laurie_Christensen@URMC.Rochester.edu

585-275-8849

Timothy M Baran, PhD

Role: primary

Timothy_Baran@URMC.Rochester.edu

585-276-3188

Laurie Christensen, BS

Role: backup

Laurie_Christensen@URMC.Rochester.edu

585-275-8849

Other Identifiers

STUDY00008702

Identifier Type: -

Identifier Source: org_study_id