New Melanoma Test Shows Three-Fold Improvement in Predicting Lymph Node Metastasis Risk
The Merlin CP-GEP test accurately stratifies melanoma patients by sentinel node metastasis risk, potentially reducing unnecessary surgical procedures through improved personalized care.
Results from the landmark MERLIN_001 trial, the largest prospective evaluation of a genomic test in cutaneous melanoma, demonstrate that the Merlin CP-GEP Test can effectively stratify patients into distinct risk categories for sentinel lymph node metastasis. Published in the October 2025 issue of JAMA Surgery, the study shows patients with a High-Risk result had a three-fold higher rate of sentinel node metastasis compared to those with a Low-Risk result (23.8% vs. 7.1%) overall.
The prospective blinded study enrolled 1,761 patients across leading U.S. academic cancer centers including the Mayo Clinic, University of Michigan, Memorial Sloan Kettering Cancer Center, and Moffitt Cancer Center. Across the study population, the Merlin CP-GEP Test successfully stratified melanomas into two distinct risk groups, with 37.0% of patients classified as Low-Risk and 63.0% as High-Risk. The test demonstrated high reliability, achieving success in 97.7% of submitted samples.
Vernon Sondak, MD, MERLIN_001 Principal Investigator and chair of the Cutaneous Oncology Department at Moffitt Cancer Center, emphasized the study's significance. "This study represents a major step forward in evaluating personalized melanoma care," Sondak stated. "Our results show that the test adds a level of accuracy above current clinical factors alone, and this kind of knowledge ultimately allows patients and surgeons to make better decisions about when sentinel node biopsy should be part of the management of clinically localized melanoma."
The test showed particular utility in challenging patient populations. In patients aged 65 and older, where comorbidities can be more prevalent, the test identified 57.9% as High-Risk with a positive SLNB rate of 20.3%, versus a 6.6% positive SLNB rate for Low-Risk cases. For head and neck melanomas, where SLNB can be technically difficult and carry higher morbidity, the Merlin CP-GEP test identified High-Risk cases with a 26.7% SLN rate and Low-Risk cases with a 4.9% SLN rate, representing a five-fold risk increase between groups.
Across all ages and primary sites, cases with clinical Stage IB melanoma were classified as Low-Risk 49.3% of the time, with a 6.5% positive SLNB rate, compared with an 18.3% rate for High-Risk cases. The MERLIN_001 trial results published in JAMA Surgery can be found at https://doi.org/10.1001/jamasurg.2025.4399. The CP-GEP model represents the latest commercially launched gene expression profiling test, developed through collaboration between Mayo Clinic and SkylineDx, and has been clinically validated in multiple studies globally.
The Merlin CP-GEP Test is the only commercially available GEP test that combines clinicopathologic variables with gene expression profiling into a single integrated algorithm, providing binary stratification of all patients based on metastasis risk. This approach assigns patients to appropriate surgical action categories as listed in evidence-based cancer treatment guidelines. More information about the test and its clinical applications is available at https://www.merlinmelanomatest.com and https://www.falconprogram.com.