Alteration of the Immune Microenvironment in Basal Cell Carcinoma Following Photodynamic Therapy

May 28, 2026 updated by: Case Comprehensive Cancer Center

Alteration of the Immune Microenvironment in Basal Cell Carcinoma (BCC) Following Photodynamic Therapy (PDT)

The purpose of this study is to better understand the immune response to basal cell carcinoma (BCC) treated with Photodynamic Therapy (PDT) in order to develop new methods of treating BCC. Previous research suggests that PDT alters the immune response, possibly in a way that could promote better tumor clearance when combined with other treatments. Overall, participation in this study will help the study team better understand the anti-tumor immune response when BCC is treated with PDT.

Study Overview

Status

Active, not recruiting

Intervention / Treatment

Detailed Description

PDT is a technique that works by combining a photosensitizing topical agent and an intense light to kill tumor cells. PDT is not currently approved for the treatment of BCC by the Food and Drug Administration (FDA), although it is approved for that purpose in many European countries.

This is an internally (bilaterally) controlled trial that will enroll 24 participants with biopsy-proven BCC who are planning to undergo tumor removal via Mohs surgery. Within this cohort, one tumor will be PDT-treated and the other left as an untreated control. This study is also a cohort-controlled trial, because discarded tissue from fully de-identified Mohs participants will be analyzed after routine Mohs surgery, in order to establish the baseline variability in tumor-infiltrating immune cell parameters in non-PDT-treated participants.

The objectives of this study are:

To determine the time to maximum expression of immune checkpoint molecules in BCC tumors and peri-tumoral stroma after PDT, as compared to untreated tumors.

To determine the ratio of cytotoxic T cells to regulatory T cells in BCC tumors and peri-tumoral stroma after PDT, as compared to untreated tumors.

To determine whether circulating T-cells, collected from patients' peripheral blood, sampled before and after PDT treatment of a BCC tumor, show a higher proportion of tumor-activated CD8+ T-cells after PDT. The hypothesis is that PDT of the localized tumor will trigger a systemic anti-tumor immune effect.

To determine the rate of protoporphyrin IX (PpIX) accumulation and maximal PpIX levels.in tumors To determine the rate of production and maximal levels of singlet oxygen (O2) produced during blue light exposure To assess change in the volume, color, and appearance of tumors at the Mohs surgery visit compared to the PDT visit To assess for distant tumor (abscopal) effects after PDT

Study Type

Interventional

Enrollment (Actual)

18

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Cleveland Clinic, Case Comprehensive Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  • Must be an adult parcticpant (> 18 yrs) who is scheduled to undergo BCC surgery (via Mohs surgery, ED&C, or standard elliptical excision) within the Dermatologic Surgery unit of the Department of Dermatology, Cleveland Clinic.
  • Must have at least one BCC tumor eligible for surgical removal
  • Participants of any ethnic group are eligible for this trial.
  • Must provide informed consent to participate in the trial.

Exclusion Criteria

  • Pregnant or breastfeeding
  • Currently being treated for other cancers with medical or radiation therapy
  • Known hypersensitivity to 5-aminolevulinic acid
  • History of a photosensitivity disease, e.g., porphyria cutanea tarda

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Photodynamic therapy (PDT)

Each participant will serve as their own control, receiving PDT for one tumor, no PDT for the second tumor (untreated control).

Visit 1:

  • Informed consent
  • Blood draw
  • Lesion(s) Photographed
  • (ALA) applied for4 hours
  • PpIX measured in lesions (PpIX buildup monitored every 30 minutes over a 4 h period)
  • PDT with blue light

Visit 2 (scheduled for within one of the following time intervals: 1-3 days, 4-7 days, or 8-14 days post-PDT):

  • Blood draw
  • Lesion(s) Photographed
  • Mohs surgery
  • After procedure, excess frozen BCC tissue will be saved for analysis
At first visit, ALA applied to one BCC lesion
Other Names:
  • Levulan
PDT with blue light (for 30 min (~20 mJ/cm2))

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to maximum expression of immune checkpoint molecules
Time Frame: at visit 2 (1-14 days)

Time (days) to maximum expression of immune checkpoint molecules in BCC tumors and peri-tumoral stroma after PDT, as compared to untreated tumors.

Data from frozen BCC specimens post-PDT by immunostaining the tumor specimens with antibodies against PD-L1, PD-1, CTLA-4 as well as the newer IC molecules TIGIT, TIM-3, and LAG-3

at visit 2 (1-14 days)
Altered expression of immune checkpoint molecules
Time Frame: at visit 2 (1-14 days)

Altered expression of immune checkpoint molecules in BCC tumor specimens after PDT.

Assessed by comparing IC molecule expression in PDT treated and untreated tumors with immunostaining in the tumor specimens with antibodies against PD-L1, PD-1, CTLA-4 as well as the newer IC molecules TIGIT, TIM-3, and LAG-3. (quantifying with immunofluorescence microscope)

at visit 2 (1-14 days)
Altered recruitment of different immune cell subtypes in BCC tumor specimens
Time Frame: at visit 2 (1-14 days)

Determine the ratio of cytotoxic T cells to regulatory T cells in BCC tumors and peri-tumoral stroma after PDT, as compared to untreated tumors.

Measured with specific antibodies against the following markers, to determine the qualitative time course of infiltration by each immune cell populations: Neutrophils (Gr1+ or MPO+); Macrophages(F4/80+); MDSCs (CD33, S100A9); cytotoxicT-cells(CD8+); regulatory T-cells(CD4+,FoxP3+,CD25+, CD127-); NK natural killer cells(CD56+CD16+).

at visit 2 (1-14 days)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of tumor-activated CD8+ T-cells after PDT
Time Frame: at visit 2 (1-14 days)

Difference in CD8 T cells after PDT collected from participants' peripheral blood, sampled before and after PDT treatment of a BCC tumor.

This data is derived from patient blood samples. Each patient will have two blood draws: at Visit 1 (before PDT, to establish a baseline) and at Visit 2. We will compare the proportion of CD8 T cells after PDT based on when the participant returns (within the 3 time ranges), and a single value (difference in CD8 T cells, measured before and after PDT) will be reported for that patient.

at visit 2 (1-14 days)
Rate of protoporphyrin IX (PpIX) accumulation in tumors
Time Frame: Every 30 minutes up to 4 hours

Relative rate of PpIX accumulation in tumors assessed via noninvasive measurements of PpIX fluorescence using a dosimeter.

PpIX will be measured every 30 minutes during the 4 hour incubation. The purpose is to monitor PDT kinetics. We will measure the level of PpIX at each time point, but the final outcome to report is relative rate of change in fluorescence intensity.

Every 30 minutes up to 4 hours
Maximal PpIX levels in tumors
Time Frame: Every 30 minutes up to 4 hours
Maximal PpIX levels in tumors, assessed via noninvasive measurements of PpIX fluorescence using a dosimeter
Every 30 minutes up to 4 hours
Change in the color of tumors
Time Frame: at visit 1 (pre PDT) and visit 2 (1-14 days)
Change in the color of tumors as reported by the participants at the Mohs surgery visit compared to the PDT visit. Number of participants that report common findings after PDT.
at visit 1 (pre PDT) and visit 2 (1-14 days)
Change in the appearance of tumors
Time Frame: at visit 1 (pre PDT) and visit 2 (1-14 days)
Change in the appearance of tumors as reported by the participants at the Mohs surgery visit compared to the PDT visit. Number of participants that report common findings after PDT. Appearance as being the shape, texture and overlying skin changes.
at visit 1 (pre PDT) and visit 2 (1-14 days)
Change in the volume of tumors
Time Frame: at visit 1 (pre PDT) and visit 2 (1-14 days)

Change in the volume of tumors at the Mohs surgery visit compared to the PDT visit.

Tumor volumes (mm3) will be determined from computerized analysis of 3-D photographs.

at visit 1 (pre PDT) and visit 2 (1-14 days)
Distant tumor (abscopal) effects after PDT
Time Frame: at visit 2 (1-14 days)
Number and type of immune cell present, expression of immune checkpoint molecules, and tumor-activated CD8 T cells present in blood compared to archived samples that did not receive PDT.
at visit 2 (1-14 days)
To determine the relationship of PDT with the expression of immune- and cancer-associated RNA molecules
Time Frame: at visit 1 (pre PDT) and visit 2 (1-14 days)
Determine whether PDT is associated with altered expression of immune- and cancer-associated RNA transcripts in BCC using NanoString nCounter.
at visit 1 (pre PDT) and visit 2 (1-14 days)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Edward V Maytin, MD, PhD, Cleveland Clinic, Case Comprehensive Cancer Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 13, 2021

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

August 19, 2021

First Submitted That Met QC Criteria

August 19, 2021

First Posted (Actual)

August 25, 2021

Study Record Updates

Last Update Posted (Actual)

June 1, 2026

Last Update Submitted That Met QC Criteria

May 28, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All IPD that underlie results in publication

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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