0000000000066514
AUTHOR
Simone M. Goldinger
The Genetic Landscape of Clinical Resistance to RAF Inhibition in Metastatic Melanoma.
Abstract Most patients with BRAFV600-mutant metastatic melanoma develop resistance to selective RAF kinase inhibitors. The spectrum of clinical genetic resistance mechanisms to RAF inhibitors and options for salvage therapy are incompletely understood. We performed whole-exome sequencing on formalin-fixed, paraffin-embedded tumors from 45 patients with BRAFV600-mutant metastatic melanoma who received vemurafenib or dabrafenib monotherapy. Genetic alterations in known or putative RAF inhibitor resistance genes were observed in 23 of 45 patients (51%). Besides previously characterized alterations, we discovered a “long tail” of new mitogen-activated protein kinase (MAPK) pathway alterations (…
Differential influence of vemurafenib and dabrafenib on patient lymphocytes despite similar clinical efficacy in melanoma
Background: Since the majority of melanomas eventually become resistant and progress, combining selective BRAF inhibitors (BRAFi) with immunotherapies has been proposed to achieve more durable treatment responses. Here, we explored the impact of selective BRAFi on the hosts’ immune system. Patients and methods: Clinical data, whole blood counts (WBC) and serum lactate dehydrogenase (LDH) of 277 vemurafenib- and 65 dabrafenib-treated melanoma patients were evaluated. The frequency and phenotype of lymphocyte subpopulations were determined by flow cytometry while T cell cytokine secretion was measured by multiplex assays. Results: Progression-free survival (PFS) as well as overall survival (O…
Acquired BRAF inhibitor resistance: A multicenter meta-analysis of the spectrum and frequencies, clinical behaviour, and phenotypic associations of resistance mechanisms.
BackgroundAcquired resistance to BRAF inhibitors (BRAFi) is a near-universal phenomenon caused by numerous genetic and non-genetic alterations. In this study, we evaluated the spectrum, onset, pattern of progression, and subsequent clinical outcomes associated with specific mechanisms of resistance.MethodsWe compiled clinical and genetic data from 100 patients with 132 tissue samples obtained at progression on BRAFi therapy from 3 large, previously published studies of BRAFi resistance. These samples were subjected to whole-exome sequencing and/or polymerase chain reaction-based genetic testing.ResultsAmong 132 samples, putative resistance mechanisms were identified in 58%, including NRAS o…
Outcome of melanoma patients with elevated LDH treated with first-line targeted therapy or PD-1-based immune checkpoint inhibition.
Abstract Background Elevated lactate dehydrogenase (LDH) is a known predictive and prognostic factor for a poor outcome in patients with metastatic melanoma. It is unclear whether first-line targeted therapy (TT) or immune checkpoint inhibition (ICI) is more beneficial in melanoma patients with elevated LDH because prospective studies in this area are lacking. Methods This multicentre retrospective cohort study was conducted at 25 melanoma centres worldwide to analyse progression-free survival (PFS) and overall survival (OS) among melanoma patients with elevated LDH. The role of confounders was addressed by using inverse probability of treatment weighting. Results Among 173 BRAFV600-mutant …
The genetic landscape of clinical resistance to RAF inhibition in melanoma.
11009 Background: Although single-agent RAF inhibition has proved effective in metastatic BRAFV600-mutant melanoma, most patients relapse and some are intrinsically resistant. While several genetic resistance effectors have been identified, a comprehensive assessment of the genetic resistance spectrum in a large patient cohort may further inform resistance patterns and treatment strategies. Methods: Pre-treatment and post-relapse biopsies were obtained from BRAFV600melanoma patients treated with vemurafenib or dabrafenib. Whole exome sequencing of tumor and normal samples was performed to identify exome-wide mutations, insertion/deletions, and chromosomal copy number alterations. Since som…
Clinical outcome of concomitant vs interrupted BRAF inhibitor therapy during radiotherapy in melanoma patients
Background: Concomitant radiation with BRAF inhibitor (BRAFi) therapy may increase radiation-induced side effects but also potentially improve tumour control in melanoma patients. Methods: A total of 155 patients with BRAF-mutated melanoma from 17 European skin cancer centres were retrospectively analysed. Out of these, 87 patients received concomitant radiotherapy and BRAFi (59 vemurafenib, 28 dabrafenib), while in 68 patients BRAFi therapy was interrupted during radiation (51 vemurafenib, 17 dabrafenib). Overall survival was calculated from the first radiation (OSRT) and from start of BRAFi therapy (OSBRAFi). Results: The median duration of BRAFi treatment interruption prior to radiothera…