Efficacy and safety of anti-PD1 monotherapy or in combination with ipilimumab after BRAF/MEK inhibitors in patients with BRAF mutant metastatic melanoma.

Patients with V600BRAF mutant metastatic melanoma have higher rates of progression-free survival (PFS) and overall survival (OS) with first-line anti-PD1 (PD1]+anti-CTLA-4 (IPI) versus PD1. Whether this is also true after BRAF/MEKi therapy is unknown. We aimed to determine the efficacy and safety of PD1 versus IPI +PD1 after BRAF/MEK inhibitors (BRAF/MEKi). Patients with V600BRAF mutant metastatic melanoma treated with BRAF/MEKi who had subsequent PD1 versus IPI+PD1 at eight centers were included. The endpoints were objective response rate (ORR), PFS, OS and safety in each group. Of 200 patients with V600E (75%) or non-V600E (25%) mutant metastatic melanoma treated with BRAF/MEKi (median time of treatment 7.6 months; treatment cessation due to progressive disease in 77%), 115 (57.5%) had subsequent PD1 and 85 (42.5%) had IPI+PD1. Differences in patient characteristics between PD1 and IPI+PD1 groups included, age (med. 63 vs 54 years), time between BRAF/MEKi and PD1±IPI (16 vs 4 days), Eastern Cooperative Oncology Group Performance Status (ECOG PS) of ≥1 (62% vs 44%), AJCC M1C/M1D stage (72% vs 94%) and progressing brain metastases at the start of PD1±IPI (34% vs 57%). Median follow-up from PD1±IPI start was 37.8 months (95% CI, 33.9 to 52.9). ORR was 36%; 34% with PD1 vs 39% with IPI+PD1 (p=0.5713). Median PFS was 3.4 months; 3.4 with PD1 vs 3.6 months with IPI+PD1 (p=0.6951). Median OS was 15.4 months; 14.4 for PD1 vs 20.5 months with IPI+PD1 (p=0.2603). The rate of grade 3 or 4 toxicities was higher with IPI+PD1 (31%) vs PD1 (7%). ORR, PFS and OS were numerically higher with IPI+PD1 vs PD1 across most subgroups except for females, those with <10 days between BRAF/MEKi and PD1±IPI, and those with stage III/M1A/M1B melanoma. The combination of ECOG PS=0 and absence of liver metastases identified patients with >3 years OS (area under the curve, AUC=0.74), while ECOG PS ≥1, progressing brain metastases and presence of bone metastases predicted primary progression (AUC=0.67). IPI+PD1 and PD1 after BRAF/MEKi have similar outcomes despite worse baseline prognostic features in the IPI+PD1 group, however, IPI+PD1 is more toxic. A combination of clinical factors can identify long-term survivors, but less accurately those with primary resistance to immunotherapy after targeted therapy.

Pires da Silva I ，Zakria D ，Ahmed T ，Trojanello C ，Dimitriou F ，Allayous C ，Gerard C ，Zimmer L ，Lo S ，Michielin O ，Lebbe C ，Mangana J ，Ascierto PA ，Johnson DB ，Carlino M ，Menzies A ，Long G ... -  《Journal for ImmunoTherapy of Cancer》

Melanoma brain metastases that progress on BRAF-MEK inhibitors demonstrate resistance to ipilimumab-nivolumab that is associated with the Innate PD-1 Resistance Signature (IPRES).

Melanoma brain metastases (MBMs) are a challenging clinical problem with high morbidity and mortality. Although first-line dabrafenib-trametinib and ipilimumab-nivolumab have similar intracranial response rates (50%-55%), central nervous system (CNS) resistance to BRAF-MEK inhibitors (BRAF-MEKi) usually occurs around 6 months, and durable responses are only seen with combination immunotherapy. We sought to investigate the utility of ipilimumab-nivolumab after MBM progression on BRAF-MEKi and identify mechanisms of resistance. Patients who received first-line ipilimumab-nivolumab for MBMs or second/third line ipilimumab-nivolumab for intracranial metastases with BRAFV600 mutations with prior progression on BRAF-MEKi and MRI brain staging from March 1, 2015 to June 30, 2018 were included. Modified intracranial RECIST was used to assess response. Formalin-fixed paraffin-embedded samples of BRAFV600 mutant MBMs that were naïve to systemic treatment (n=18) or excised after progression on BRAF-MEKi (n=14) underwent whole transcriptome sequencing. Comparative analyses of MBMs naïve to systemic treatment versus BRAF-MEKi progression were performed. Twenty-five and 30 patients who received first and second/third line ipilimumab-nivolumab, were included respectively. Median sum of MBM diameters was 13 and 20.5 mm for the first and second/third line ipilimumab-nivolumab groups, respectively. Intracranial response rate was 75.0% (12/16), and median progression-free survival (PFS) was 41.6 months for first-line ipilimumab-nivolumab. Efficacy of second/third line ipilimumab-nivolumab after BRAF-MEKi progression was poor with an intracranial response rate of 4.8% (1/21) and median PFS of 1.3 months. Given the poor activity of ipilimumab-nivolumab after BRAF-MEKi MBM progression, we performed whole transcriptome sequencing to identify mechanisms of drug resistance. We identified a set of 178 differentially expressed genes (DEGs) between naïve and MBMs with progression on BRAF-MEKi treatment (p value <0.05, false discovery rate (FDR) <0.1). No distinct pathways were identified from gene set enrichment analyses using Kyoto Encyclopedia of Genes and Genomes, Gene Ontogeny or Hallmark libraries; however, enrichment of DEG from the Innate Anti-PD1 Resistance Signature (IPRES) was identified (p value=0.007, FDR=0.03). Second-line ipilimumab-nivolumab for MBMs after BRAF-MEKi progression has poor activity. MBMs that are resistant to BRAF-MEKi that also conferred resistance to second-line ipilimumab-nivolumab showed enrichment of the IPRES gene signature.

Lau PKH ，Feran B ，Smith L ，Lasocki A ，Molania R ，Smith K ，Weppler A ，Angel C ，Kee D ，Bhave P ，Lee B ，Young RJ ，Iravani A ，Yeang HA ，Vergara IA ，Kok D ，Drummond K ，Neeson PJ ，Sheppard KE ，Papenfuss T ，Solomon BJ ，Sandhu S ，McArthur GA ... -  《Journal for ImmunoTherapy of Cancer》

Real-world survival of patients with advanced BRAF V600 mutated melanoma treated with front-line BRAF/MEK inhibitors, anti-PD-1 antibodies, or nivolumab/ipilimumab.

The optimal treatment sequence for patients with advanced BRAF V600 mutant melanoma is unknown. BRAF/MEK inhibition (BRAF/MEKi), single agent anti-PD-1 (aPD-1) antibodies and combination immune checkpoint inhibition with nivolumab and ipilimumab (niv/ipi) are all approved; however, they have not been prospectively compared. Therefore, we sought to compare overall survival of patients with advanced BRAF mutant melanoma treated with either front-line BRAF/MEKi, aPD-1, or niv/ipi. Patients with advanced BRAF mutant melanoma who had received BRAF/MEKi, niv/ipi, or aPD-1 in the front-line setting were identified from a nationwide database comprising de-identified patient-level structured and unstructured data derived from electronic health records. Survival was compared using Kaplan-Meier curves and log-rank analysis. Univariate and multivariate Cox regression models were used to measure the effect of front-line treatment, age (>64 or not), LDH (elevated or not), and Eastern Cooperative Oncology Group (ECOG) performance status (>1 or not) on survival. Five hundred and sixty seven patients with advanced disease and treated with front-line aPD-1 (n = 162), BRAF/MEKi (n = 297) or niv/ipi (n = 108) were identified. With a median follow-up of 22.4 months, median overall survival (OS) for patients treated with front-line niv/ipi was not reached (NR) while median OS for patients treated with aPD-1 or BRAF/MEKi was 39.5 months and 13.2 months, respectively. Front-line treatment with PD-1 and niv/ipi were associated with statistically longer survival than BRAF/MEKi in multivariate analyses. In our real-world retrospective analysis, patients with advanced BRAF mutant melanoma treated with front-line niv/ipi or aPD-1 had longer survival compared to those treated with front-line BRAF/MEKi.

Moser JC ，Chen D ，Hu-Lieskovan S ，Grossmann KF ，Patel S ，Colonna SV ，Ying J ，Hyngstrom JR ... -  《Cancer Medicine》

Association of BRAF V600E/K Mutation Status and Prior BRAF/MEK Inhibition With Pembrolizumab Outcomes in Advanced Melanoma: Pooled Analysis of 3 Clinical Trials.

Puzanov I ，Ribas A ，Robert C ，Schachter J ，Nyakas M ，Daud A ，Arance A ，Carlino MS ，O'Day SJ ，Long GV ，Margolin KA ，Dummer R ，Schadendorf D ，Lutzky J ，Ascierto PA ，Tarhini A ，Lin J ，Mogg R ，Homet Moreno B ，Ibrahim N ，Hamid O ... -  《-》

Clinical Predictors of Survival in Patients With BRAFV600-Mutated Metastatic Melanoma Treated With Combined BRAF and MEK Inhibitors After Immune Checkpoint Inhibitors.

Prospective and between trial comparisons indicate that first-line treatment with immune checkpoint inhibitors improves survival outcomes compared to first-line therapy with combined BRAF and MEK inhibitors in metastatic melanoma containing BRAFV600E/K mutations. Long-term outcomes for BRAF/MEK inhibition after progression on immunotherapy have not been reported. Moreover, clinical variables associated with outcome from treatment with combined BRAF/MEK inhibition were previously identified in the first-line setting but have not been investigated when targeted therapies are administered after progression on immune therapy. We performed a retrospective single institution analysis of 40 metastatic melanoma patients receiving combined BRAF/MEK inhibitors after progression on an anti-PD-1 or ipilimumab plus nivolumab to assess response rate by RECIST 1.1, progression-free and overall survival (PFS and OS). Pretreatment clinical variables were analyzed for association with OS. Ipilimumab/nivolumab was the first-line immunotherapy regimen in 39 patients (97.5%), and BRAFV600E/K mutations were present in 33 (83%) and 7 (17%) patients, respectively. The median OS from start of BRAF/MEK inhibitors was 20.3 months (1.73-106.4+, 95% CI of median 13.3-30.7). Clinical characteristics associated with worse survival prior to starting BRAF/MEK inhibitors included age > 60 years (median OS 14 vs. 28 months; HR 2.5; 95% CI 0.91-6.87, P = .023), ECOG-PS > 2 (median OS 7 vs. 33 months; HR 2.89; 95% CI 0.78-10.76, P = .018), and presence of bone metastases (median OS 9 vs. 52 months; HR 3.17; 95% CI 1.33-7.54, P = .002). These associations with shorter survival maintained their significance on multivariate analysis. If confirmed in larger cohorts, the identified prognostic variables can be used for stratification of patients in future randomized trials.

Kahn AM ，Perry CJ ，Etts K ，Kluger H ，Sznol M ... -  《-》