Anti-PD-1 alone or in combination with anti-CTLA-4 for advanced melanoma patients with liver metastases.

BACKGROUND: The combination of anti-PD-1 and anti-CTLA-4 has been associated with improvement in response and survival over anti-PD-1 monotherapy in unselected patients with advanced melanoma. Whether patients with liver metastases also benefit from the combination of anti-PD-1 and anti-CTLA-4 over anti-PD-1, is unclear. In this study, we sought to assess whether the combination of anti-PD-1 and anti-CTLA-4 leads to better response, progression-free survival and overall survival, compared with anti-PD-1 monotherapy for patients with liver metastases. METHODS: We have conducted an international multicentre retrospective study. Patients with advanced melanoma with liver metastases treated with 1st line anti-PD1 monotherapy or with anti-CTLA-4 were included. The endpoints of this study were: objective response rate, progression-free survival and overall survival. RESULTS: With a median follow-up from commencement of anti-PD-1 monotherapy or in combination with anti-CTLA-4 of 47 months (95% CI, 42-51), objective response rate was higher with combination therapy (47%) versus anti-PD-1 monotherapy (35%) (p = 0.0027), while progression-free survival and overall survival were not statistically different between both treatment groups. However, on multivariable analysis with multiple imputation for missing values and adjusting for predefined variables, combination of anti-PD1 and anti-CTLA-4 was associated with higher objective response (OR 2.21, 1.46 - 3.36; p < 0.001), progression-free survival (HR 0.73, 0.57 - 0.92; p = 0.009) and overall survival (HR 0.71, 0.54 - 0.94; p = 0.018) compared to anti-PD1 monotherapy. CONCLUSIONS: Findings from this study will help guide treatment selection for patients who present with liver metastases, suggesting that combination therapy should be considered for this group of patients.

First-line chemoimmunotherapy and immunotherapy in patients with non-small cell lung cancer and brain metastases: a registry study.

Introduction: Brain metastases commonly occur in patients with non-small cell lung cancer (NSCLC). Standard first-line treatment for NSCLC, without an EGFR, ALK or ROS1 mutation, is either chemoimmunotherapy or anti-PD-1 monotherapy. Traditionally, patients with symptomatic or untreated brain metastases were excluded from the pivotal clinical trials that established first-line treatment recommendations. The intracranial effectiveness of these treatment protocols has only recently been elucidated in small-scale prospective trials. Methods: Patients with NSCLC and brain metastases, treated with first-line chemoimmunotherapy or anti-PD-1 monotherapy were selected from the Australian Registry and biObank of thoracic cancers (AURORA) clinical database covering seven institutions. The primary outcome was a composite time-to-event (TTE) outcome, including extracranial and intracranial progression, death, or need for local intracranial therapy, which served as a surrogate for disease progression. The secondary outcome included overall survival (OS), intracranial objective response rate (iORR) and objective response rate (ORR). Results: 116 patients were included. 63% received combination chemoimmunotherapy and 37% received anti-PD-1 monotherapy. 69% of patients received upfront local therapy either with surgery, radiotherapy or both. The median TTE was 7.1 months (95% CI 5 - 9) with extracranial progression being the most common progression event. Neither type of systemic therapy or upfront local therapy were predictive of TTE in a multivariate analysis. The median OS was 17 months (95% CI 13-27). Treatment with chemoimmunotherapy was predictive of longer OS in multivariate analysis (HR 0.35; 95% CI 0.14 - 0.86; p=0.01). The iORR was 46.6%. The iORR was higher in patients treated with chemoimmunotherapy compared to immunotherapy (58% versus 31%, p=0.01). The use of chemoimmunotherapy being predictive of iORR in a multivariate analysis (OR 2.88; 95% CI 1.68 - 9.98; p=0.04). Conclusion: The results of this study of real-world data demonstrate the promising intracranial efficacy of chemoimmunotherapy in the first-line setting, potentially surpassing that of immunotherapy alone. No demonstrable difference in survival or TTE was seen between receipt of upfront local therapy. Prospective studies are required to assist clinical decision making regarding optimal sequencing of local and systemic therapies.

Seasonal patterns of toxicity in melanoma patients treated with combination anti-PD-1 and anti-CTLA-4 immunotherapy.

BACKGROUND: Immune checkpoint inhibitors are frequently associated with the development of immunotherapy-related adverse events (irAEs). The exact etiology, including the role of environmental factors, remains incompletely understood. METHODS: We analyzed the records of 394 melanoma patients from three centers (northern and southern hemisphere). Patients had received at least one cycle of anti-PD-1/anti-CTLA-4 with a minimum follow-up of 3 months. We study the distribution and time to irAEs onset throughout the calendar year. RESULTS: 764 irAEs were recorded; the most frequent were skin rash (35%), hepatitis (32%) and colitis (30%). The irAEs incidence was the highest in autumn and winter, and the ratio for the 'number of irAEs' per 'therapies commenced' was the highest in winter and lowest in summer (2.4 and 1.7, respectively). Season-specific patterns in the time of irAEs onset were observed for pneumonitis (shorter time to onset in autumn, p = 0.025), hepatitis (shorter time to onset in spring, p = 0.016) and sarcoid-like immune reaction (shorter time to onset in autumn, p = 0.041). Season-specific patterns for early-onset irAEs were observed for hepatitis (spring, p = 0.023) and nephritis (summer, p = 0.017). Early-onset pneumonitis was more frequent in autumn-winter (p = 0.008) and early-onset nephritis in spring-summer (p = 0.004). CONCLUSIONS: Environmental factors that are associated with particular seasons may contribute to the development of certain irAEs and suggest the potential effect of environmental triggers. The identification of these factors may enhance preventive and therapeutic strategies to reduce the morbidity of irAEs.

Brief Report: Real-World Toxicity and Survival of Combination Immunotherapy in Pleural Mesothelioma-RIOMeso.

BACKGROUND: Australia has one of the highest rates of asbestos-associated diseases. Mesothelioma remains an area of unmet need with a 5-year overall survival of 10%. First-line immunotherapy with ipilimumab and nivolumab is now a standard of care for unresectable pleural mesothelioma following the CheckMate 743 trial, with supportive data from the later line single-arm MAPS2 trial. RIOMeso evaluates survival and toxicity of this regimen in real-world practice. METHODS: Demographic and clinicopathologic data of Australian patients treated with ipilimumab and nivolumab in first- and subsequent-line settings for pleural mesothelioma were collected retrospectively. Survival was reported using the Kaplan-Meier method and compared between subgroups with the log-rank test. Toxicity was investigator assessed using Common Terminology Criteria for Adverse Events version 5.0. RESULTS: A total of 119 patients were identified from 11 centers. The median age was 72 years, 83% were male, 92% had Eastern Cooperative Oncology Group less than or equal to 1, 50% were past or current smokers, and 78% had known asbestos exposure. In addition, 50% were epithelioid, 19% sarcomatoid, 14% biphasic, and 17% unavailable. Ipilimumab and nivolumab were used first line in 75% of patients. Median overall survival (mOS) was 14.5 months (95% confidence interval [CI]: 13.0-not reached [NR]) for the entire cohort. For patients treated first line, mOS was 14.5 months (95% CI: 12.5-NR) and in second- or later-line patients was 15.4 months (95% CI: 11.2-NR). There was no statistically significant difference in mOS for epithelioid patients compared with nonepithelioid (19.1 mo [95% CI: 15.4-NR] versus 13.0 mo [95% CI: 9.7-NR], respectively, p = 0.064). Furthermore, 24% of the patients had a Common Terminology Criteria for Adverse Events grade greater than or equal to 3 adverse events, including three treatment-related deaths. Colitis was the most frequent adverse event. CONCLUSIONS: Combination immunotherapy in real-world practice has poorer survival outcomes and seems more toxic compared with clinical trial data. This is the first detailed report of real-world survival and toxicity outcomes using ipilimumab and nivolumab treatment of pleural mesothelioma.

Lag-3 expression and clinical outcomes in metastatic melanoma patients treated with combination anti-lag-3 + anti-PD-1-based immunotherapies.

Lymphocyte-activation gene-3 (LAG-3), an immune checkpoint receptor, negatively regulates T-cell function and facilitates immune escape of tumors. Dual inhibition of LAG-3 and programmed cell death receptor-1 (PD-1) significantly improved progression-free survival (PFS) in metastatic melanoma patients compared to anti-PD-1 therapy alone. Investigating the utility of LAG-3 expression as a biomarker of response to anti-LAG-3 + anti-PD-1 immunotherapy is of great clinical relevance. This study sought to evaluate the association between baseline LAG-3 expression and clinical outcomes following anti-LAG-3 and anti-PD-1-based immunotherapy in metastatic melanoma. LAG-3 immunohistochemistry (clone D2G4O) was performed on pre-treatment formalin-fixed, paraffin-embedded metastatic melanoma specimens from 53 patients treated with combination anti-LAG-3 + anti-PD-1-based therapies. Eleven patients had received prior anti-PD-1-based treatment. Patients were categorized as responders (complete/partial response; n = 36) or non-responders (stable/progressive disease; n = 17) based on the Response Evaluation Criteria in Solid Tumours (RECIST). Tumor-infiltrating lymphocytes (TILs) were scored on hematoxylin and eosin-stained sections. LAG-3 expression was observed in 81% of patients, with staining in TILs and dendritic cells. Responders displayed significantly higher proportions of LAG-3+ cells compared to non-responders (P = .0210). LAG-3 expression positively correlated with TIL score (P < .01). There were no significant differences in LAG-3 expression between different sites of metastases (P > .05). Patients with ≥ 1% LAG-3+ cells in their tumors had significantly longer PFS compared to patients with < 1% LAG-3 expression (P = .0037). No significant difference was observed in overall survival between the two groups (P = .1417). Therefore, the assessment of LAG-3 expression via IHC warrants further evaluation to determine its role as a predictive marker of response and survival in metastatic melanoma.

Classification of the tumor immune microenvironment and associations with outcomes in patients with metastatic melanoma treated with immunotherapies.

BACKGROUND: Tumor microenvironment (TME) characteristics are potential biomarkers of response to immune checkpoint inhibitors in metastatic melanoma. This study developed a method to perform unsupervised classification of TME of metastatic melanoma. METHODS: We used multiplex immunohistochemical and quantitative pathology-derived assessment of immune cell compositions of intratumoral and peritumoral regions of metastatic melanoma baseline biopsies to classify TME in relation to response to anti-programmed cell death protein 1 (PD-1) monotherapy or in combination with anti-cytotoxic T-cell lymphocyte-4 (ipilimumab (IPI)+PD-1). RESULTS: Spatial profiling of CD8+T cells, macrophages, and melanoma cells, as well as phenotypic PD-1 receptor ligand (PD-L1) and CD16 proportions, were used to identify and classify patients into one of three mutually exclusive TME classes: immune-scarce, immune-intermediate, and immune-rich tumors. Patients with immune-rich tumors were characterized by a lower proportion of melanoma cells and higher proportions of immune cells, including higher PD-L1 expression. These patients had higher response rates and longer progression-free survival (PFS) than those with immune-intermediate and immune-scarce tumors. At a median follow-up of 18 months (95% CI: 6.7 to 49 months), the 1-year PFS was 76% (95% CI: 64% to 90%) for patients with an immune-rich tumor, 56% (95% CI: 44% to 72%) for those with an immune-intermediate tumor, and 33% (95% CI: 23% to 47%) for patients with an immune-scarce tumor. A higher response rate was observed in patients with an immune-scarce or immune-intermediate tumor when treated with IPI+PD-1 compared with those treated with PD-1 alone. CONCLUSIONS: Our study provides an automatic TME classification method that may predict the clinical efficacy of immunotherapy for patients with metastatic melanoma.

Definitive treatment with PD-1 blockade and radiation therapy of unresected primary desmoplastic melanoma of the nose.

Two patients with primary desmoplastic melanoma of the nose were treated with definitive anti-PD-1 checkpoint inhibitor (anti-PD1) and radiation therapy. Both patients were technically resectable with partial rhinectomy but both declined for cosmetic reasons. The melanoma multidisciplinary team recommended that the patients receive PD1 blockade. The initial response to PD-1 blockade was temporary in the first case and partial in the second one. With the addition of high-dose radiotherapy, complete responses were obtained in both patients, with recurrence-free and good functional and cosmetic outcomes at a six-year and 22-month follow-up. Despite surgery being the gold standard, both cases illustrated that PD-1 blockade and radiation therapy can be a safe alternative option for desmoplastic melanoma where surgery is morbidly disfiguring.

Durability of response to immune checkpoint inhibitors in metastatic Merkel cell carcinoma after treatment cessation.

BACKGROUND: Metastatic Merkel cell carcinoma (mMCC) is highly responsive to immune checkpoint inhibitors (ICIs); however, durability of response after treatment cessation and response to retreatment in the setting of progression is unknown. METHODS: Patients (pts) having mMCC from 10 centres who discontinued ICI treatment for a reason other than progression were studied. RESULTS: Forty patients were included. Median time on treatment was 13.5 months (range 1-35). Thirty-one patients (77.5%) stopped treatment electively while 9 patients (22.5%) stopped due to treatment-related toxicity. After median of 12.3 months from discontinuation, 14 pts (35%) have progressed (PD). Disease progression rate following ICI discontinuation was 26% (8 of 31) in patients who discontinued in complete response (CR), 57% (4 of 7) in patients in partial response and 100% (2 of 2) in those with stable disease. Median progression-free survival (PFS) after treatment cessation was 21 months (95% confidence interval [CI], 18- not reached [NR]), with a third of patients progressing during their first year off treatment. PFS was longer for patients who discontinued ICI electively (median PFS 29 months; 95% CI, 21-NR) compared to those who stopped due to toxicity (median PFS 11 months; 95% CI, 10-NR). ICI was restarted in 8 of 14 pts (57%) with PD, with response rate of 75% (4 CR, 2 partial response, 1 stable disease, 1 PD). CONCLUSION: ICI responses in mMCC do not appear durable off treatment, including in patients who achieve a CR, though response to retreatment is promising. Extended duration of treatment needs to be investigated to optimise long-term outcomes.

The effect of organ-specific tumor microenvironments on response patterns to immunotherapy.

Immunotherapy, particularly immune checkpoint inhibitors, have become widely used in various settings across many different cancer types in recent years. Whilst patients are often treated on the basis of the primary cancer type and clinical stage, recent studies have highlighted disparity in response to immune checkpoint inhibitors at different sites of metastasis, and their impact on overall response and survival. Studies exploring the tumor immune microenvironment at different organ sites have provided insights into the immune-related mechanisms behind organ-specific patterns of response to immunotherapy. In this review, we aimed to highlight the key learnings from clinical studies across various cancers including melanoma, lung cancer, renal cell carcinoma, colorectal cancer, breast cancer and others, assessing the association of site of metastasis and response to immune checkpoint inhibitors. We also summarize the key clinical and pre-clinical findings from studies exploring the immune microenvironment of specific sites of metastasis. Ultimately, further characterization of the tumor immune microenvironment at different metastatic sites, and understanding the biological drivers of these differences, may identify organ-specific mechanisms of resistance, which will lead to more personalized treatment approaches for patients with innate or acquired resistance to immunotherapy.

Real-world outcomes with ipilimumab and nivolumab in advanced melanoma: a multicentre retrospective study.

PURPOSE: To assess efficacy and toxicity of combination immunotherapy with ipilimumab plus nivolumab in routine practice in a retrospective multicentre cohort of patients with advanced melanoma. PATIENTS AND METHODS: This retrospective analysis included patients with advanced melanoma treated with ipilimumab and nivolumab between October 2015 and January 2020 at six centres in Australia, Europe and the United States of America. We describe efficacy outcomes (overall survival [OS], progression-free survival [PFS] and objective response rate [ORR]) in treatment-naïve and pre-treated patients, with and without brain metastases, plus treatment-related adverse events (trAEs) in all patients treated. RESULTS: A total of 697 patients were identified; 472 were treatment-naïve of which 138 (29.2%) had brain metastases, and 225 were previously treated of which 102 (45.3%) had brain metastases. At baseline, 32.3% had stage M1c and 34.4% stage M1d disease. Lactate dehydrogenase was high in 280 patients (40.2%). With a median follow-up of 25.9 months, median OS in the 334 treatment-naïve patients without brain metastases was 53.7 months (95% confidence interval [CI] 40.8-NR) and 38.7 months (95% CI 18.6-NR) for the 138 treatment-naïve patients with brain metastases. For the entire cohort the ORR was 48%, for treatment-naïve patients without brain metastases ORR was 56.6% with a median PFS of was 13.7 months (95% CI 9.6-26.5). Median PFS was 7.9 months (95% CI 5.8-10.4) and OS 38 months (95% CI 31-NR) for the entire cohort. Grade 3-4 trAE were reported in 44% of patients, and 4 (0.7%) treatment-related deaths (1 pneumonitis, 2 myocarditis and 1 colitis) were recorded. CONCLUSION: The outcome and toxicity of combination immunotherapy with ipilimumab and nivolumab in a real-world patient population are similar to those reported in pivotal trials.

Unveiling the tumor immune microenvironment of organ-specific melanoma metastatic sites.

BACKGROUND: The liver is a known site of resistance to immunotherapy and the presence of liver metastases is associated with shorter progression-free and overall survival (OS) in melanoma, while lung metastases have been associated with a more favorable outcome. There are limited data available regarding the immune microenvironment at different anatomical sites of melanoma metastases. This study sought to characterize and compare the tumor immune microenvironment of liver, brain, lung, subcutaneous (subcut) as well as lymph node (LN) melanoma metastases. METHODS: We analyzed OS in 1924 systemic treatment-naïve patients with AJCC (American Joint Committee on Cancer) stage IV melanoma with a solitary site of organ metastasis. In an independent cohort we analyzed and compared immune cell densities, subpopulations and spatial distribution in tissue from liver, lung, brain, LN or subcut sites from 130 patients with stage IV melanoma. RESULTS: Patients with only liver, brain or bone metastases had shorter OS compared to those with lung, LN or subcutaneous and soft tissue metastases. Liver and brain metastases had significantly lower T-cell infiltration than lung (p=0.0116 and p=0.0252, respectively) and LN metastases (p=0.0116 and p=0.0252, respectively). T cells were further away from melanoma cells in liver than lung metastases (p=0.0335). Liver metastases displayed unique T-cell profiles, with a significantly lower proportion of programmed cell death protein-1+ T cells compared to all other anatomical sites (p<0.05), and a higher proportion of TIM-3+ T cells compared to LN (p=0.0004), subcut (p=0.0082) and brain (p=0.0128) metastases. Brain metastases had a lower macrophage density than subcut (p=0.0105), liver (p=0.0095) and lung (p<0.0001) metastases. Lung metastases had the highest proportion of programmed death ligand-1+ macrophages of the total macrophage population, significantly higher than brain (p<0.0001) and liver metastases (p=0.0392). CONCLUSIONS: Liver and brain melanoma metastases have a significantly reduced immune infiltrate than lung, subcut and LN metastases, which may account for poorer prognosis and reduced immunotherapy response rates in patients with liver or brain metastases. Increased TIM-3 expression in liver metastases suggests TIM-3 inhibitor therapy as a potential therapeutic opportunity to improve patient outcomes.

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

BACKGROUND: 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). METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Higher proportions of CD39+ tumor-resident cytotoxic T cells predict recurrence-free survival in patients with stage III melanoma treated with adjuvant immunotherapy.

BACKGROUND: Adjuvant immune checkpoint inhibitor (ICI) immunotherapies have significantly reduced the recurrence rate in high-risk patients with stage III melanoma compared with surgery alone. However, 48% of anti-PD-1-treated patients will develop recurrent disease within 4 years. There is a need to identify biomarkers of recurrence after adjuvant ICI to enable identification of patients in need of alternative treatment strategies. As cytotoxic T cells are critical for the antitumor response to anti-PD-1, we sought to determine whether specific subsets were predictive of recurrence in anti-PD-1-treated high-risk patients with stage III melanoma. METHODS: Associations with recurrence in patients with stage III melanoma were sought by analyzing resection specimens (n=103) taken prior to adjuvant nivolumab/pembrolizumab±low-dose/low-interval ipilimumab. Multiplex immunohistochemistry was used to quantify intratumoral CD8+ T-cell populations using phenotypical markers CD39, CD103, and PD-1. RESULTS: With a median follow-up of 19.3 months, 37/103 (36%) of patients had a recurrence. Two CD8+ T-cell subpopulations were significantly associated with recurrence. First, CD39+ tumor-resident memory cells (CD39+CD103+PD-1+CD8+ (CD39+ Trm)) comprised a significantly higher proportion of CD8+ T cells in recurrence-free patients (p=0.0004). Conversely, bystander T cells (CD39-CD103-PD-1-CD8+) comprised a significantly greater proportion of T cells in patients who developed recurrence (p=0.0002). Spatial analysis identified that CD39+ Trms localized significantly closer to melanoma cells than bystander T cells. Multivariable analysis confirmed significantly improved recurrence-free survival (RFS) in patients with a high proportion of intratumoral CD39+ Trms (1-year RFS high 78.1% vs low 49.9%, HR 0.32, 95% CI 0.15 to 0.69), no complete lymph node dissection performed, and less advanced disease stage (HR 2.85, 95% CI 1.13 to 7.19, and HR 1.29, 95% CI 0.59 to 2.82). The final Cox regression model identified patients who developed recurrence with an area under the curve of 75.9% in the discovery cohort and 69.5% in a separate validation cohort (n=33) to predict recurrence status at 1 year. CONCLUSIONS: Adjuvant immunotherapy-treated patients with a high proportion of CD39+ Trms in their baseline melanoma resection have a significantly reduced risk of melanoma recurrence. This population of T cells may not only represent a biomarker of RFS following anti-PD-1 therapy, but may also be an avenue for therapeutic manipulation and enhancing outcomes for immunotherapy-treated patients with cancer.

Lack of association between anatomical sites of scalp melanomas and brain metastases does not support direct vascular spread.

Primary scalp melanomas are associated with a higher rate of brain metastasis than primary cutaneous melanomas occurring at other head and neck and body sites, but the reason is unclear. Spread to brain parenchyma via emissary veins draining from the scalp to dural sinuses has been suggested. We sought to examine the locations of metastases from primary scalp and nonscalp head and neck melanomas to determine whether there was anatomical evidence supporting direct venous spread to the brain. Data from patients who developed distant metastases from cutaneous head and neck melanomas (CHNMs) between 2000 and 2018 were analyzed. Anatomical sites of primary scalp melanomas and their respective intracranial metastases were compared. Times to first brain and nonbrain metastases were investigated for scalp and nonscalp primary CHNMs. Of 693 patients with CHNMs, 244 developed brain metastases: 109 (44.7%) had scalp primaries and 135 (55.3%) had nonscalp primaries. There was no significant association between anatomical sites of scalp primary melanomas and brain metastases (Cramer's V = 0.21; Chi-square P = 0.63). Compared with nonscalp CHNMs, scalp melanomas had no greater propensity for the brain as the first distant metastatic site ( P = 0.52) but had a shorter time to both brain metastasis (76.3 vs. 168.5 months; P < 0.001) and nonbrain metastasis (22.6 vs. 35.8 months; P < 0.001). No evidence was found to support a direct vascular pathway for metastatic spread of scalp melanomas to the brain. The increased incidence of brain metastases from scalp melanomas is probably driven by aggressive biological mechanisms.

Clinical Models to Define Response and Survival With Anti-PD-1 Antibodies Alone or Combined With Ipilimumab in Metastatic Melanoma.

PURPOSE: Currently, there are no robust biomarkers that predict immunotherapy outcomes in metastatic melanoma. We sought to build multivariable predictive models for response and survival to anti-programmed cell death protein 1 (anti-PD-1) monotherapy or in combination with anticytotoxic T-cell lymphocyte-4 (ipilimumab [IPI]; anti-PD-1 ± IPI) by including routine clinical data available at the point of treatment initiation. METHODS: One thousand six hundred forty-four patients with metastatic melanoma treated with anti-PD-1 ± IPI at 16 centers from Australia, the United States, and Europe were included. Demographics, disease characteristics, and baseline blood parameters were analyzed. The end points of this study were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The final predictive models for ORR, PFS, and OS were determined through penalized regression methodology (least absolute shrinkage and selection operator method) to select the most significant predictors for all three outcomes (discovery cohort, N = 633). Each model was validated internally and externally in two independent cohorts (validation-1 [N = 419] and validation-2 [N = 592]) and nomograms were created. RESULTS: The final model for predicting ORR (area under the curve [AUC] = 0.71) in immunotherapy-treated patients included the following clinical parameters: Eastern Cooperative Oncology Group Performance Status, presence/absence of liver and lung metastases, serum lactate dehydrogenase, blood neutrophil-lymphocyte ratio, therapy (monotherapy/combination), and line of treatment. The final predictive models for PFS (AUC = 0.68) and OS (AUC = 0.77) included the same variables as those in the ORR model (except for presence/absence of lung metastases), and included presence/absence of brain metastases and blood hemoglobin. Nomogram calculators were developed from the clinical models to predict outcomes for patients with metastatic melanoma treated with anti-PD-1 ± IPI. CONCLUSION: Newly developed combinations of routinely collected baseline clinical factors predict the response and survival outcomes of patients with metastatic melanoma treated with immunotherapy and may serve as valuable tools for clinical decision making.

BRAF mutation testing for patients diagnosed with stage III or stage IV melanoma: practical guidance for the Australian setting.

Targeted therapy (BRAF inhibitor plus MEK inhibitor) is now among the possible treatment options for patients with BRAF mutation-positive stage III or stage IV melanoma. This makes prompt BRAF mutation testing an important step in the management of patients diagnosed with stage III or IV melanoma; one that can help better ensure that the optimal choice of systemic treatment is initiated with minimal delay. This article offers guidance about when and how BRAF mutation testing should be conducted when patients are diagnosed with melanoma in Australia. Notably, it recommends that pathologists reflexively order BRAF mutation testing whenever a patient is found to have American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) stage III or IV melanoma (i.e., any metastatic spread beyond the primary tumour) and that patient's BRAF mutation status is hitherto unknown, even if BRAF mutation testing has not been specifically requested by the treating clinician (in Australia, Medicare-subsidised BRAFV600 mutation testing does not need to be requested by the treating clinician). When performed in centres with appropriate expertise and experience, immunohistochemistry (IHC) using the anti-BRAF V600E monoclonal antibody (VE1) can be a highly sensitive and specific means of detecting BRAFV600E mutations, and may be used as a rapid and relatively inexpensive initial screening test. However, VE1 immunostaining can be technically challenging and difficult to interpret, particularly in heavily pigmented tumours; melanomas with weak, moderate or focal BRAFV600E immunostaining should be regarded as equivocal. It must also be remembered that other activating BRAFV600 mutations (including BRAFV600K), which account for ∼10-20% of BRAFV600 mutations, are not detected with currently available IHC antibodies. For these reasons, if available and practicable, we recommend that DNA-based BRAF mutation testing always be performed, regardless of whether IHC-based testing is also conducted. Advice about tissue/specimen selection for BRAF mutation testing of patients diagnosed with stage III or IV melanoma is also offered in this article; and potential pitfalls when interpreting BRAF mutation tests are highlighted.

Multiomic profiling of checkpoint inhibitor-treated melanoma: Identifying predictors of response and resistance, and markers of biological discordance.

We concurrently examine the whole genome, transcriptome, methylome, and immune cell infiltrates in baseline tumors from 77 patients with advanced cutaneous melanoma treated with anti-PD-1 with or without anti-CTLA-4. We show that high tumor mutation burden (TMB), neoantigen load, expression of IFNγ-related genes, programmed death ligand expression, low PSMB8 methylation (therefore high expression), and T cells in the tumor microenvironment are associated with response to immunotherapy. No specific mutation correlates with therapy response. A multivariable model combining the TMB and IFNγ-related gene expression robustly predicts response (89% sensitivity, 53% specificity, area under the curve [AUC], 0.84); tumors with high TMB and a high IFNγ signature show the best response to immunotherapy. This model validates in an independent cohort (80% sensitivity, 59% specificity, AUC, 0.79). Except for a JAK3 loss-of-function mutation, for patients who did not respond as predicted there is no obvious biological mechanism that clearly explained their outlier status, consistent with intratumor and intertumor heterogeneity in response to immunotherapy.

Re-induction ipilimumab following acquired resistance to combination ipilimumab and anti-PD-1 therapy.

PURPOSE: Combination immunotherapy with nivolumab and ipilimumab has a high initial response rate in advanced melanoma; however, up to 55% of patients later progress. The efficacy and safety of ipilimumab re-induction in the setting of acquired resistance (AR) to combination immunotherapy is unknown. METHODS: Patients with advanced melanoma who initially achieved a complete response, partial response or sustained stable disease to induction combination immunotherapy then progressed and were reinduced with ipilimumab (alone or in combination with anti-PD-1) and were analysed retrospectively. Demographics, disease characteristics, efficacy and toxicity were examined. RESULTS: Forty-seven patients were identified from 12 centres. The response rate to reinduction therapy was 12/47 (26%), and disease control rate was 21/47 (45%). Responses appeared more frequent in patients who developed AR after ceasing induction immunotherapy (30% vs. 18%, P = 0.655). Time to AR was 11 months (95% confidence interval [CI], 8-15 months). After a median follow-up of 16 months (95% CI, 10-25 months), responders to reinduction had a median progression-free survival of 14 months (95% CI, 13, NR months), and in the whole cohort, the median overall survival from reinduction was 17 months (95% CI, 12-NR months). Twenty-seven (58%) immune-related adverse events (irAEs) were reported; 18 (38%) were grade 3/4, and in 11 of 27 (40%), the same irAE observed during induction therapy recurred. CONCLUSIONS: Reinduction with ipilimumab ± anti-PD-1 has modest clinical activity. Clinicians should be attentive to the risk of irAEs, including recurrence of irAEs that occurred during induction therapy. Future studies are necessary to determine best management after resistance to combination immunotherapy.

Clinical and Molecular Heterogeneity in Patients with Innate Resistance to Anti-PD-1 +/- Anti-CTLA-4 Immunotherapy in Metastatic Melanoma Reveals Distinct Therapeutic Targets.

While immune checkpoint inhibitors targeting the CTLA-4 and PD-1 receptors have significantly improved outcomes of many patients with metastatic melanoma, there remains a group of patients who demonstrate no benefit. In this study, we sought to characterise patients who do not respond to anti-PD-1-based therapies based on their clinical, genetic and immune profiles. Forty patients with metastatic melanoma who did not respond to anti-PD-1 +/- anti-CTLA-4 treatment were identified. Targeted RNA sequencing (n = 37) was performed on pretreatment formalin-fixed paraffin-embedded (FFPE) melanoma specimens. Patients clustered into two groups based on the expression profiles of 26 differentially expressed genes: an immune gene rich group (n = 17) expressing genes associated with immune and T cell signalling, and a second group (n = 20) expressing genes associated with metabolism, signal transduction and neuronal signalling. Multiplex immunohistochemistry validated significantly higher densities of tumour-infiltrating lymphocytes (TILs) and macrophages in the immune gene-rich group. This TIL-high subset of patients also demonstrated higher expression of alternative immune-regulatory drug targets compared to the TIL-low group. Patients were also subdivided into rapid progressors and other progressors (cut-off 2 mo progression-free survival), with significantly lower TILs (p = 0.04) and CD68+ macrophages (p = 0.0091) in the rapid progressors. Furthermore, a trend towards a higher tumour burden was observed in rapid progressors (p = 0.06). These data highlight the need for a personalised and multilayer (clinical and molecular) approach for identifying the most appropriate treatments for anti-PD-1 resistant patients and provides insight into how individual treatment strategies can be achieved.