FAQ: MERLIN_001 Study and Merlin CP-GEP Test for Melanoma Risk Stratification

What is the main finding of the MERLIN_001 study?

The study confirmed that the Merlin CP-GEP Test accurately stratifies melanoma patients into distinct risk groups for sentinel node metastasis, with High-Risk patients having a three-fold higher rate of metastasis (23.8%) compared to Low-Risk patients (7.1%).

Why is this study considered significant for melanoma care?

This represents the first and only prospective blinded data confirming the test’s accuracy and provides quantitative guidance for clinicians in making sentinel lymph node biopsy decisions, adding accuracy beyond current clinical factors alone.

How does the Merlin CP-GEP Test work?

The Merlin CP-GEP Test is a non-invasive prediction model that combines clinico-pathological factors with gene expression profiling to stratify melanoma patients into High-Risk and Low-Risk groups for sentinel node metastasis.

Who conducted this study and where was it published?

The MERLIN_001 trial was conducted by SkylineDx across leading U.S. academic cancer centers and was published in the October 2025 issue of JAMA Surgery, the most cited surgery journal in the world.

What patient populations were included in the study?

The study enrolled 1,761 patients with T1-T3 melanomas across multiple leading cancer centers including Mayo Clinic, University of Michigan, Memorial Sloan Kettering, and Moffitt Cancer Center.

How effective was the test in different patient subgroups?

The test showed strong performance across subgroups: in patients 65+, High-Risk cases had 20.3% SLNB positivity vs 6.6% for Low-Risk; in head/neck melanomas, High-Risk had 26.7% vs 4.9% for Low-Risk (five-fold difference).

What percentage of patients were classified as Low-Risk versus High-Risk?

Overall, 37.0% of patients were classified as Low-Risk while 63.0% were classified as High-Risk, and the test was successful in 97.7% of submitted samples.

How does this test compare to current clinical assessment methods?

According to the principal investigator, the test adds accuracy above current clinical factors alone, even when factors like mitotic rate and histologic subtype are considered, providing rigor and precision no other test or nomogram can match.

What are the practical implications for patients and surgeons?

The test enables better shared decision-making about when sentinel node biopsy should be part of melanoma management, particularly helping avoid unnecessary procedures in Low-Risk patients while identifying High-Risk patients who would benefit from SLNB.

Where can I find the full study results?

The complete MERLIN_001 trial results can be found at https://doi.org/10.1001/jamasurg.2025.4399 in JAMA Surgery.