A noninvasive clinicopathologic and gene expression profiling (CP-GEP)–based tool, the Merlin assay, shows promise for identifying recurrence risks in patients with early-stage melanoma who do not undergo sentinel lymph node biopsy (SNLB).
This was the conclusion of a retrospective analysis of a large cohort of patients with stage I/II disease, reported by Teresa Amaral, MD, PhD, at the 11th World Congress of Melanoma and 21st EADO Congress 2025.
Of 930 patients included in the study, the assay identified 879 as having a low risk for recurrence and 51 as having high risk for recurrence. The overall 5-year recurrence-free survival (RFS), distant metastasis-free survival (DMFS) and melanoma-specific survival (MSS) rates were 90.9%, 96.9%, and 97.5%, respectively.
The corresponding rates among those stratified by the assay as having low vs high recurrence risk, respectively, were 94.6% and 26.6% for RFS (hazard ratio [HR], 25.08), 98.6% vs 62.1% for DMFS (HR, 35.39), and 99.4% vs 61.7% for MSS (HR, 71.05), said Amaral, during her presentation at the meeting.
Of 16 melanoma-specific deaths, 12 were stratified as high risk for recurrence by the CP-GEP assay, said Amaral, head of the Skin Cancer Clinical Trials Center at the University of Tübingen, Tübingen, Germany, and first author of the study.
Study participants had stages IA-IIC melanoma, 41% were women, and median age was 64 years. Median melanoma thickness was 0.5 mm, and 94% were not ulcerated.
No systemic treatment options currently exist for patients with this early-stage disease, the author said.
The CP-GEP model, initially developed by the Mayo Clinic and SkylineDx BV to predict the positivity of SNLB, has been validated in multiple studies.
Amaral and her colleagues previously demonstrated the ability of the CP-GEP model to stratify patients with stages I-II disease as having low or high risk for recurrence — including in a small number of patients without SNLB. Those findings are confirmed in this larger population of patients who did not undergo SNLB, she said.
SkylineDx announced the findings in a press release stating the results validate the prognostic power of the Merlin assay for “identifying tumors at high risk for relapse that would otherwise be missed by traditional clinical and pathological evaluation.”
SNLB is the gold standard for nodal assessment for staging cutaneous melanoma. More than 80% of patients who undergo SNLB are negative for nodal metastases, but most patients who relapse or die from their melanoma are initially stratified by SNLB as having low-risk early-stage disease, Amaral explained. This suggests “SNLB is not enough,” she noted.
The findings suggest that CP-GEP has the potential to risk stratify patients with early-stage melanoma that did not undergo SLNB and help select those who can forgo SLNB, she said.
Without another means of assessing risk, patients considered low risk based on SNLB are closely followed, the author explained.
“If we could identify the very low-risk patient and then allocate the resources to the very high-risk patients who really need a more detailed and more tailored approach…we would be doing a favor to our patients,” the author concluded.
Amaral disclosed personal financial relationships with Delcath, Philogen, Bristol Myers Squibb, NeraCare, Novartis, Pierre Fabre, CeCaVa, and MedTrix.
Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape Medical News, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X @SW_MedReporter.
