Molecular Profiling and Matched Targeted Therapy for Patients With Advanced Melanoma: Results From Part 1 of the MatchMEL Study.
Although the clinicopathologic features of BRAF/NRAS-mutant melanoma are well defined, the molecular landscape, clinicopathologic features, and treatment outcomes of BRAF/NRAS wild-type (WT) patients on immune checkpoint inhibitors (ICIs) remain less clear. The MatchMEL study investigated the mutational profile of WT melanoma (Part 1) and examined whether targeted treatments could be matched to specific molecular alterations with clinical activity (Part 2). We report findings from Part 1 only, focusing on the genomic landscape and clinicopathologic correlates in ICI-treated patients.
In Part 1, consecutive patients with advanced melanoma at two Australian centers were enrolled. BRAF/NRAS WT patients underwent FoundationOneCDx (F1CDx) sequencing. Clinical, pathologic, and treatment data were collected. Patients were stratified by mutational status (BRAF, NRAS, NF1, triple WT), and associations between tumor mutational burden (TMB), overall response rates (ORR), and survival outcomes (progression-free survival [PFS]) were analyzed using logistic regression and Kaplan-Meier methods. A molecular tumor board analyzed F1CDx results to match targeted therapy to molecular alterations. Part 2 assessed outcomes for patients treated with matched targeted therapies.
From 2021 to 2023, 210 patients were enrolled. Fifty-seven (27%) had BRAF V600 mutation, 53 (25%) had NRAS mutation, and 100 (48%) were BRAF/NRAS WT. Of these, 86 underwent profiling; NF1 mutations were detected in 37 (43%) and were associated with the highest median TMB (53 mut/Mb). NF1-mutant melanoma had a numerically longer median PFS (26.8 months [95% CI, 20.2 to not reached]; P = .58) and higher ORR (63%; P = .67) to first-line ICIs than other subtypes.
Our findings suggest significant clinical, pathologic, and molecular correlations in an Australian cohort of advanced melanoma treated with ICIs. Patients with NF1 mutation exhibited higher TMB, which was associated with improved response to ICIs.
In Part 1, consecutive patients with advanced melanoma at two Australian centers were enrolled. BRAF/NRAS WT patients underwent FoundationOneCDx (F1CDx) sequencing. Clinical, pathologic, and treatment data were collected. Patients were stratified by mutational status (BRAF, NRAS, NF1, triple WT), and associations between tumor mutational burden (TMB), overall response rates (ORR), and survival outcomes (progression-free survival [PFS]) were analyzed using logistic regression and Kaplan-Meier methods. A molecular tumor board analyzed F1CDx results to match targeted therapy to molecular alterations. Part 2 assessed outcomes for patients treated with matched targeted therapies.
From 2021 to 2023, 210 patients were enrolled. Fifty-seven (27%) had BRAF V600 mutation, 53 (25%) had NRAS mutation, and 100 (48%) were BRAF/NRAS WT. Of these, 86 underwent profiling; NF1 mutations were detected in 37 (43%) and were associated with the highest median TMB (53 mut/Mb). NF1-mutant melanoma had a numerically longer median PFS (26.8 months [95% CI, 20.2 to not reached]; P = .58) and higher ORR (63%; P = .67) to first-line ICIs than other subtypes.
Our findings suggest significant clinical, pathologic, and molecular correlations in an Australian cohort of advanced melanoma treated with ICIs. Patients with NF1 mutation exhibited higher TMB, which was associated with improved response to ICIs.
Authors
Boutros Boutros, Carlino Carlino, Chaganti Chaganti, Gonzalez Gonzalez, Lo Lo, Pires da Silva Pires da Silva, Wong Wong, McKeown McKeown, Colebatch Colebatch, Rawson Rawson, Páramo Páramo, Scolyer Scolyer, Rizos Rizos, Wilmott Wilmott, Long Long, Menzies Menzies
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