PRAME Immunohistochemistry-Guided Slow Mohs Micrographic Surgery for the Treatment of Stage 0 to IIc Cutaneous Melanoma

PRAME (Preferentially Expressed Antigen in Melanoma) Immunohistochemistry Guided Slow-Mohs Micrographic Surgery of Malignant Melanoma: A Pragmatic Clinical Trial

This clinical trial tests the addition of preferentially expressed antigen in melanoma (PRAME) immunohistochemical (IHC) staining to standard slow Mohs micrographic surgery (SMMS) for guiding tissue removal in patients with stage 0 to IIc cutaneous melanoma. SMMS is a method of skin cancer removal involving repeated tissue removal and examination under a microscope to ensure the tumor is removed as much as possible while sparing healthy tissue. In SMMS, tissue sections are evaluated to determine whether additional tissue removal is needed. The standard method for evaluating the tissue is by using a specific stain called hematoxylin and eosin (H&E) stains. PRAME is a cancer antigen that is being investigated as a diagnostic marker in certain types of cancer. Adding PRAME IHC analysis to standard SMMS staining methods may improve the accuracy for determining whether additional tissue removal is necessary for patients undergoing SMMS for stage 0 to IIc cutaneous melanoma.

Study Overview

• Status: Suspended
• Conditions: Clinical Stage 0 Cutaneous Melanoma AJCC v8; Clinical Stage I Cutaneous Melanoma AJCC v8; Clinical Stage II Cutaneous Melanoma AJCC v8
• Intervention / Treatment: Diagnostic test: Immunohistochemistry Staining Method; Procedure: Mohs Surgery

Detailed Description

PRIMARY OBJECTIVE:

I. To compare the efficacy of PRAME IHC-guided slow Mohs micrographic surgery to routine slow Mohs micrographic surgical practices in patients with melanoma.

SECONDARY OBJECTIVE:

I. To further evaluate the efficacy of PRAME IHC-guided slow Mohs micrographic surgical practices in patients with melanoma.

OUTLINE:

Patients undergo standard slow Mohs micrographic surgery with the addition of PRAME IHC analysis per the discretion of the surgeon on study.

After completion of study treatment, patients are followed up every 6 months for up to 5 years.

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Sacramento, California, United States, 95817
      • University of California Davis Comprehensive Cancer Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Scheduled for SMMS of cutaneous melanoma (stage 0 through stage IIc per American Joint Committee on Cancer [AJCC] criteria)
• Age >= 18 years at time of consent
• Initial tumor biopsy is PRAME positive or PRAME testing was not done. PRAME testing must be planned if not done
• Provision of signed and dated informed consent form
• Stated willingness to comply with all study procedures and availability for the duration of the study

Exclusion Criteria:

• Initial biopsy was PRAME negative
• Incarcerated persons
• Patient with severe, active co-morbidity that would preclude a SMMS of cutaneous melanoma (stage 0 through stage IIc per AJCC criteria)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment (PRAME IHC-guided SMMS); Patients undergo standard slow Mohs micrographic surgery with the addition of PRAME IHC analysis per the discretion of the surgeon on study.	Diagnostic test: Immunohistochemistry Staining Method; Undergo Preferentially Expressed Antigen in Melanoma (PRAME) IHC analysis; Other Names: Immunohistochemistry; IHC; Cell/Tissue, Immunohistochemistry; Immunohistochemistry (IHC); PRAME; Preferentially Expressed Antigen in Melanoma; Procedure: Mohs Surgery; Undergo slow Mohs micrographic surgery; Other Names: Mohs Micrographic Surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Margin status	Margin status (positive, negative, or uncertain) will be evaluated from hematoxylin and eosin (H&E)/SOX-10 + preferentially expressed antigen in melanoma (PRAME) stained sections versus H&E/SOX-10 stained sections. For PRAME stained sections, margins will be considered positive when > 75% PRAME+ malignant cells at the tissue margin are observed. The McNemar's test will be used to compare the margin status between the predetermined gold-standard (i.e., H&E/SOX-10) and H&E/SOX-10 + PRAME.	During slow Mohs micrographic surgery (SMMS) procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Presence of PRAME+ suprabasilar melanocytes in the tissue sections	Will be reported using descriptive statistics, including frequency tables as appropriate.	During SMMS procedure
Density of PRAME+ cells	Will be reported as a quartile system (0% positive, 1-25% positive, 26-50% positive, 51-75% positive and > 75% positive). Will be reported using descriptive statistics, including frequency tables as appropriate.	During SMMS procedure
Number of stages needed for clear margins	Will be reported using descriptive statistics, including frequency tables as appropriate.	During SMMS procedure
Local recurrence of the excised melanoma	Will be reported using descriptive statistics, including frequency tables as appropriate.	Up to 5 years following SMMS
Incidence of regional and distant metastases	Will be reported using descriptive statistics, including frequency tables as appropriate.	Up to 5 years following SMMS

Collaborators and Investigators

• Sponsor: University of California, Davis
• Collaborators: National Cancer Institute (NCI)
• Investigators: Principal Investigator: Daniel B Eisen, University of California, Davis

Study record dates

Study Major Dates

• Study Start (Actual): October 24, 2025
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): November 1, 2033

Study Registration Dates

• First Submitted: November 20, 2025
• First Submitted That Met QC Criteria: November 20, 2025
• First Posted (Actual): December 2, 2025

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Surgical Procedures, Operative; Cytological Techniques; Histocytochemistry; Histological Techniques; Immunologic Techniques; Plastic Surgery Procedures; Dermatologic Surgical Procedures; Microsurgery; Immunohistochemistry; Mohs Surgery
• Other Study ID Numbers: UCDCC324 (Other Identifier: University of California Davis Comprehensive Cancer Center); P30CA093373 (U.S. NIH Grant/Contract); NCI-2025-08321 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

Drug and device information, study documents

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