A randomized phase II clinical trial of stereotactic body radiation therapy (SBRT) and systemic pembrolizumab with or without intratumoral avelumab/ipilimumab plus CD1c (BDCA-1)+/CD141 (BDCA-3)+ myeloid dendritic cells in solid tumors.

BACKGROUND: Radiotherapy (RT) synergizes with immune checkpoint blockade (ICB). CD1c(BDCA-1)+/CD141(BDCA-3)+ myeloid dendritic cells (myDC) in the tumor microenvironment are indispensable at initiating effector T-cell responses and response to ICB. METHODS: In this phase II clinical trial, anti-PD-1 ICB pretreated oligometastatic patients (tumor agnostic) underwent a leukapheresis followed by isolation of CD1c(BDCA-1)+/CD141(BDCA-3)+ myDC. Following hypofractionated stereotactic body RT (3 × 8 Gy), patients were randomized (3:1). Respectively, in arm A (immediate treatment), intratumoral (IT) ipilimumab (10 mg) and avelumab (40 mg) combined with intravenous (IV) pembrolizumab (200 mg) were administered followed by IT injection of myDC; subsequently, IV pembrolizumab and IT ipilimumab/avelumab were continued (q3W). In arm B (contemporary control arm), patients received IV pembrolizumab, with possibility to cross-over at progression. Primary endpoint was 1-year progression-free survival rate (PFS). Secondary endpoints were safety, feasibility, objective response rate, PFS, and overall survival (OS). RESULTS: Thirteen patients (10 in arm A, eight non-small cell lung cancer, and five melanoma) were enrolled. Two patients crossed over. One-year PFS rate was 10% in arm A and 0% in arm B. Two patients in arm A obtained a partial response, and one patient obtained a stable disease as best response. In arm B, one patient obtained a SD. Median PFS and OS were 21.8 weeks (arm A) versus 24.9 (arm B), and 62.7 versus 57.9 weeks, respectively. An iatrogenic pneumothorax was the only grade 3 treatment-related adverse event. CONCLUSION: SBRT and pembrolizumab with or without IT avelumab/ipilimumab and IT myDC in oligometastatic patients are safe and feasible with a clinically meaningful tumor response rate. However, the study failed to reach its primary endpoint. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov: NCT04571632 (09 AUG 2020). EUDRACT: 2019-003668-32. Date of registration: 17 DEC 2019, amendment 1: 6 MAR 2021, amendment 2: 4 FEB 2022.

Health-related quality of life and neurocognitive functioning in patients with recurrent glioblastoma treated with intracerebral immune checkpoint inhibition.

PURPOSE: After glioblastoma (GB) recurrence, prognosis is very cumbersome. Therefore, health-related quality of life (HRQoL) and neurocognitive functioning (NCF) have become important endpoints in clinical trials when evaluating novel treatments. We aimed to evaluate the HRQoL and NCF in patients with recurrent glioblastoma (rGB) treated with a combination of surgical intervention (reoperation or biopsy) and intracerebral immune checkpoint inhibition. METHODS: Patients who participated in the trial (N = 23), at a single-center university hospital were included. Data were collected using 3 patient-reported outcome measures (EORTC-QLQ-C30, EORTC-QLQ-BN20, and HADS) and computerized NCF testing. In the responder group, baseline values were compared to results at a 6-month follow-up. Additionally, exploratory analyses compared baseline HRQoL and NCF between responders and non-responders. RESULTS: There were five responders and 18 non-responders. When comparing the mean and individual baseline with follow-up results for the responders, we observed overall a stable to slight clinically relevant improvement of HRQoL in multiple subsets of the questionnaires while maintaining a stable NCF. One patient deteriorated on anxiety and depression symptoms from baseline to follow-up. CONCLUSIONS: In patients that responded to intracerebral immunotherapy in our institutional trial, HRQoL and NCF remained stable over time, suggesting that no detrimental effect on cognitive function or quality of life may be expected with this treatment approach. Furthermore, there seems to be an overall tendency for responders to score better on HRQoL and NCF than non-responders at baseline.

Current "state of the art" on dendritic cell-based cancer vaccines in melanoma.

PURPOSE OF REVIEW: Dendritic cells (DCs) are the gatekeepers of our immune system and indispensable in the antitumor immune response. In recent years, their classification has been revised considerably using single-cell sequencing approaches. In this review, we focus on their unique role in cancer and how specific DC subsets can be manipulated to induce an effective and durable antitumor response. RECENT FINDINGS: Historically, due to the ease of their isolation in sufficient cell numbers from peripheral blood, the utility of monocyte-derived DCs as therapeutic cancer vaccines was explored in the clinic. However, it became clear that naturally circulating myeloid DCs (myDC), exerting their physiological role, are a functionally more powerful cellular source of antigen presenting cells. With the advent of immunomagnetic bead technology to isolate naturally circulating DC subsets, the therapeutic value of these myDC subsets is currently being explored. Since DCs are also needed in the tumor microenvironment in order to "relicense" the activity of antitumor T cells, also intratumoral administration routes for DC vaccines are explored. In addition, to circumvent the use of expensive cellular vaccines, approaches to attract DCs to the tumor microenvironment are considered of interest in order to repair a defective cancer-immunity cycle. SUMMARY: In recent years, the type of DCs used for vaccination and their administration route evolved considerably. Intratumoral vaccination strategies require combination with additional stimuli to ensure proper functioning of DCs in the tumor microenvironment. Moreover, intratumoral administration limits the applicability to patients with accessible lesions.

Perspectives in Immunotherapy: meeting report from Immunotherapy Bridge (Naples, November 30th-December 1st, 2022).

The discovery and development of novel treatments that harness the patient's immune system and prevent immune escape has dramatically improved outcomes for patients across cancer types. However, not all patients respond to immunotherapy, acquired resistance remains a challenge, and responses are poor in certain tumors which are considered to be immunologically cold. This has led to the need for new immunotherapy-based approaches, including adoptive cell transfer (ACT), therapeutic vaccines, and novel immune checkpoint inhibitors. These new approaches are focused on patients with an inadequate response to current treatments, with emerging evidence of improved responses in various cancers with new immunotherapy agents, often in combinations with existing agents. The use of cell therapies, drivers of immune response, and trends in immunotherapy were the focus of the Immunotherapy Bridge (November 30th-December 1st, 2022), organized by the Fondazione Melanoma Onlus, Naples, Italy, in collaboration with the Society for Immunotherapy of Cancer.

Melanoma with genetic alterations beyond the BRAFV600 mutation: management and new insights.

PURPOSE OF REVIEW: Molecular-targeted therapy with BRAF-/MEK-inhibitors has shown impressive activity in patients with advanced BRAFV600 mutant melanoma. In this review, we aim to summarize recent data and possible future therapeutic strategies involving small-molecule molecular-targeted therapies for advanced BRAFV600 wild-type melanoma. RECENT FINDINGS: In patients with NRASQ61 mutant melanoma, downstream MEK-inhibition has shown some albeit low activity. MEK-inhibitors combined with novel RAF dimer inhibitors, such as belvarafenib, or with CDK4/6-inhibitors have promising activity in NRAS mutant melanoma in early-phase trials. In patients with non-V600 BRAF mutant melanoma, MEK-inhibition with or without BRAF-inhibition appears to be effective, although large-scale prospective trials are lacking. As non-V600 BRAF mutants signal as dimers, novel RAF dimer inhibitors are also under investigation in this setting. MEK-inhibition is under investigation in NF1 mutant melanoma. Finally, in patients with BRAF/NRAS/NF1 wild-type melanoma, imatinib or nilotinib can be effective in cKIT mutant melanoma. Despite preclinical data suggesting synergistic activity, the combination of the MEK-inhibitor cobimetinib with the immune checkpoint inhibitor atezolizumab was not superior to the immune checkpoint inhibitor pembrolizumab. SUMMARY: As of today, no molecular-targeted therapies have shown to improve survival in patients with advanced BRAFV600 wild-type melanoma. Combinatorial strategies, involving MEK-inhibitors, RAF dimer inhibitors and CDK4/6-inhibitors, are currently under investigation and have promising activity in advanced BRAFV600 wild-type melanoma.

Perspectives in Melanoma: meeting report from the Melanoma Bridge (December 2nd - 4th, 2021, Italy).

Advances in immune checkpoint and combination therapy have led to improvement in overall survival for patients with advanced melanoma. Improved understanding of the tumor, tumor microenvironment and tumor immune-evasion mechanisms has resulted in new approaches to targeting and harnessing the host immune response. Combination modalities with other immunotherapy agents, chemotherapy, radiotherapy, electrochemotherapy are also being explored to overcome resistance and to potentiate the immune response. In addition, novel approaches such as adoptive cell therapy, oncogenic viruses, vaccines and different strategies of drug administration including sequential, or combination treatment are being tested. Despite the progress in diagnosis of melanocytic lesions, correct classification of patients, selection of appropriate adjuvant and systemic theràapies, and prediction of response to therapy remain real challenges in melanoma. Improved understanding of the tumor microenvironment, tumor immunity and response to therapy has prompted extensive translational and clinical research in melanoma. There is a growing evidence that genomic and immune features of pre-treatment tumor biopsies may correlate with response in patients with melanoma and other cancers, but they have yet to be fully characterized and implemented clinically. Development of novel biomarker platforms may help to improve diagnostics and predictive accuracy for selection of patients for specific treatment. Overall, the future research efforts in melanoma therapeutics and translational research should focus on several aspects including: (a) developing robust biomarkers to predict efficacy of therapeutic modalities to guide clinical decision-making and optimize treatment regimens, (b) identifying mechanisms of therapeutic resistance to immune checkpoint inhibitors that are potentially actionable, (c) identifying biomarkers to predict therapy-induced adverse events, and (d) studying mechanism of actions of therapeutic agents and developing algorithms to optimize combination treatments. During the Melanoma Bridge meeting (December 2nd-4th, 2021, Naples, Italy) discussions focused on the currently approved systemic and local therapies for advanced melanoma and discussed novel biomarker strategies and advances in precision medicine as well as the impact of COVID-19 pandemic on management of melanoma patients.

Oncolytic Herpes Simplex Virus Type 1 Induces Immunogenic Cell Death Resulting in Maturation of BDCA-1+ Myeloid Dendritic Cells.

Recently, a paradigm shift has been established for oncolytic viruses (OVs) as it was shown that the immune system plays an important role in the specific killing of tumor cells by OVs. OVs have the intrinsic capacity to provide the right signals to trigger anti-tumor immune responses, on the one hand by delivering virus-derived innate signals and on the other hand by inducing immunogenic cell death (ICD), which is accompanied by the release of various damage-associated molecules from infected tumor cells. Here, we determined the ICD-inducing capacity of Talimogene laherparepvec (T-VEC), a herpes simplex virus type 1 based OV, and benchmarked this to other previously described ICD (e.g., doxorubicin) and non-ICD inducing agents (cisplatin). Furthermore, we studied the capability of T-VEC to induce the maturation of human BDCA-1+ myeloid dendritic cells (myDCs). We found that T-VEC treatment exerts direct and indirect anti-tumor effects as it induces tumor cell death that coincides with the release of hallmark mediators of ICD, while simultaneously contributing to the maturation of BDCA-1+ myDCs. These results unequivocally cement OVs in the category of cancer immunotherapy.

Perspectives in Melanoma: meeting report from the Melanoma Bridge (December 3rd-5th, 2020, Italy).

Advances in immune checkpoint therapy and targeted therapy have led to improvement in overall survival for patients with advanced melanoma. Single agent checkpoint PD-1 blockade and combination with BRAF/MEK targeted therapy demonstrated benefit in overall survival (OS). Superior response rates have been demonstrated with combined PD-1/CTLA-4 blockade, with a significant OS benefit compared with single-agent PD-1 blockade. Despite the progress in diagnosis of melanocytic lesions, correct classification of patients, selection of appropriate adjuvant and systemic therapies, and prediction of response to therapy remain real challenges in melanoma. Improved understanding of the tumor microenvironment, tumor immunity and response to therapy has prompted extensive translational and clinical research in melanoma. Development of novel biomarker platforms may help to improve diagnostics and predictive accuracy for selection of patients for specific treatment. There is a growing evidence that genomic and immune features of pre-treatment tumor biopsies may correlate with response in patients with melanoma and other cancers but they have yet to be fully characterized and implemented clinically. Overall, the progress in melanoma therapeutics and translational research will help to optimize treatment regimens to overcome resistance and develop robust biomarkers to guide clinical decision-making. During the Melanoma Bridge meeting (December 3rd-5th, 2020, Italy) we reviewed the currently approved systemic and local therapies for advanced melanoma and discussed novel biomarker strategies and advances in precision medicine.

Acute exudative polymorphous vitelliform maculopathy during pembrolizumab treatment for metastatic melanoma: a case report.

BACKGROUND: The use of immunomodulating therapy to treat various cancers has been on the rise and these immune checkpoint inhibitors are known to cause ocular side effects. In this article a case of acute exudative polymorphous vitelliform maculopathy (AEPVM) is reported which developed during a first line treatment with pembrolizumab. CASE PRESENTATION: A 54-year-old woman was referred because of blurry vision in both eyes with a yellow spot in the central visual field of the left eye. These symptoms started after four treatments with pembrolizumab (a monoclonal antibody against the programmed cell death receptor-1) for a metastatic recurrent vaginal mucosal melanoma. Her best corrected visual acuity was 10/10 in both eyes with a correction of + 2.00 bilaterally. There were no inflammatory findings in the anterior segment or the vitreous. Fundoscopy revealed an attenuation of the foveal reflex with subtle yellow-white subretinal macular deposits (vitelliform lesions) in both eyes. Fluorescein angiography did not show staining or leakage in the mid-phase, neither a late staining. Spectral-domain optical coherence tomography of the macula illustrated bilateral neurosensory retinal detachment with a thick, highly reflective band at the outer photoreceptor segment. En face structural OCT at the level of the photoreceptors showed focal areas of increased signal corresponding to hyperreflective vitelliform material. The treatment with pembrolizumab was ceased immediately. During the following visits we slowly saw an improvement of the neurosensory retinal detachment. After almost four months a total resolution of the subretinal fluid was visualized in both eyes without the use of additional treatment, though the vitelliform deposits persisted. CONCLUSIONS: The development of AEPVM in melanoma patients could be triggered by treatment with Pembrolizumab. Pembrolizumab has the potential to disturb indirectly the retinal pigment epithelium homeostasis with accumulation of lipofuscin deposits and subretinal fluid, both signs of AEPVM.

A randomized controlled phase II clinical trial on mRNA electroporated autologous monocyte-derived dendritic cells (TriMixDC-MEL) as adjuvant treatment for stage III/IV melanoma patients who are disease-free following the resection of macrometastases.

BACKGROUND: Autologous monocyte-derived mRNA co-electroporated dendritic cells with mRNA encoding CD40 ligand (CD40L), CD70 and a constitutively activated TLR4 (caTLR4) (referred to as TriMixDC-MEL) have anti-tumor activity in advanced melanoma patients. We investigated the safety and activity of adjuvant TriMixDC-MEL in stage III/IV melanoma patients. MATERIALS AND METHODS: Forty-one patients were randomly assigned to treatment with TriMixDC-MEL (n = 21) and standard follow-up (n = 20). "Cross-over" was allowed at the time of non-salvageable recurrence. The primary endpoint was the percentage of patients alive and disease-free at 1-year. For a subset of patients, (formalin-fixed paraffin-embedded), tumor tissue samples were available for mRNA expression profiling and PD-L1 immunohistochemical staining. RESULTS: Baseline characteristics were well balanced. One-year after randomization, 71% of patients in the study arm were alive and free of disease compared to 35% in the control arm. After a median follow-up of 53 months (range 3-67), 23 patients experienced a non-salvageable melanoma recurrence (TriMixDC-Mel arm n = 9 and control arm n = 14).The median time to non-salvageable recurrence was superior in the TriMixDC-MEL arm (median 8 months (range 1-6) vs. not reached; log-rank p 0.044). TriMixDC-MEL-related adverse events (AE) consisted of transient local skin reactions, flu-like symptoms and post-infusion chills. No grade ≥ 3 AE's occurred. The mRNA expression profiling revealed four genes (STAT2, TPSAB1, CD9 and CSF2) as potential predictive biomarkers. CONCLUSION: TriMixDC-MEL id/iv as adjuvant therapy is tolerable and may improve the 1-year disease-free survival rate. Combination of optimized autologous monocyte-derived DC-formulations warrants further investigation in combination with currently approved adjuvant therapy options.

Pembrolizumab versus ipilimumab in advanced melanoma (KEYNOTE-006): post-hoc 5-year results from an open-label, multicentre, randomised, controlled, phase 3 study.

BACKGROUND: Pembrolizumab improved progression-free survival and overall survival versus ipilimumab in patients with advanced melanoma and is now a standard of care in the first-line setting. However, the optimal duration of anti-PD-1 administration is unknown. We present results from 5 years of follow-up of patients in KEYNOTE-006. METHODS: KEYNOTE-006 was an open-label, multicentre, randomised, controlled, phase 3 study done at 87 academic institutions, hospitals, and cancer centres in 16 countries. Patients aged at least 18 years with Eastern Cooperative Oncology Group performance status of 0 or 1, ipilimumab-naive histologically confirmed advanced melanoma with known BRAFV600 status and up to one previous systemic therapy were randomly assigned (1:1:1) to intravenous pembrolizumab 10 mg/kg every 2 weeks or every 3 weeks or four doses of intravenous ipilimumab 3 mg/kg every 3 weeks. Treatments were assigned using a centralised, computer-generated allocation schedule with blocked randomisation within strata. Exploratory combination of data from the two pembrolizumab dosing regimen groups was not protocol-specified. Pembrolizumab treatment continued for up to 24 months. Eligible patients who discontinued pembrolizumab with stable disease or better after receiving at least 24 months of pembrolizumab or discontinued with complete response after at least 6 months of pembrolizumab and then progressed could receive an additional 17 cycles of pembrolizumab. Co-primary endpoints were overall survival and progression-free survival. Efficacy was analysed in all randomly assigned patients, and safety was analysed in all randomly assigned patients who received at least one dose of study treatment. Exploratory assessment of efficacy and safety at 5 years' follow-up was not specified in the protocol. Data cutoff for this analysis was Dec 3, 2018. Recruitment is closed; the study is ongoing. This study is registered with ClinicalTrials.gov, number NCT01866319. FINDINGS: Between Sept 18, 2013, and March 3, 2014, 834 patients were enrolled and randomly assigned to receive pembrolizumab (every 2 weeks, n=279; every 3 weeks, n=277), or ipilimumab (n=278). After a median follow-up of 57·7 months (IQR 56·7-59·2) in surviving patients, median overall survival was 32·7 months (95% CI 24·5-41·6) in the combined pembrolizumab groups and 15·9 months (13·3-22·0) in the ipilimumab group (hazard ratio [HR] 0·73, 95% CI 0·61-0·88, p=0·00049). Median progression-free survival was 8·4 months (95% CI 6·6-11·3) in the combined pembrolizumab groups versus 3·4 months (2·9-4·2) in the ipilimumab group (HR 0·57, 95% CI 0·48-0·67, p<0·0001). Grade 3-4 treatment-related adverse events occurred in 96 (17%) of 555 patients in the combined pembrolizumab groups and in 50 (20%) of 256 patients in the ipilimumab group; the most common of these events were colitis (11 [2%] vs 16 [6%]), diarrhoea (ten [2%] vs seven [3%]), and fatigue (four [<1%] vs three [1%]). Any-grade serious treatment-related adverse events occurred in 75 (14%) patients in the combined pembrolizumab groups and in 45 (18%) patients in the ipilimumab group. One patient assigned to pembrolizumab died from treatment-related sepsis. INTERPRETATION: Pembrolizumab continued to show superiority over ipilimumab after almost 5 years of follow-up. These results provide further support for use of pembrolizumab in patients with advanced melanoma. FUNDING: Merck Sharp & Dohme.

Undetectable circulating tumor DNA (ctDNA) levels correlate with favorable outcome in metastatic melanoma patients treated with anti-PD1 therapy.

BACKGROUND: Treatment with anti-PD1 monoclonal antibodies improves the survival of metastatic melanoma patients but only a subgroup of patients benefits from durable disease control. Predictive biomarkers for durable benefit could improve the clinical management of patients. METHODS: Plasma samples were collected from patients receiving anti-PD1 therapy for ctDNA quantitative assessment of BRAFV600 and NRASQ61/G12/G13 mutations. RESULTS: After a median follow-up of 84 weeks 457 samples from 85 patients were analyzed. Patients with undetectable ctDNA at baseline had a better PFS (Hazard ratio (HR) = 0.47, median 26 weeks versus 9 weeks, p = 0.01) and OS (HR = 0.37, median not reached versus 21.3 weeks, p = 0.005) than patients with detectable ctDNA. Additionally, the HR for death was lower after the ctDNA level became undetectable during follow-up (adjusted HR: 0.16 (95% CI 0.07-0.36), p-value < 0.001). ctDNA levels > 500 copies/ml at baseline or week 3 were associated with poor clinical outcome. Patients progressive exclusively in the central nervous system (CNS) had undetectable ctDNA at baseline and at subsequent assessments. In multivariate analysis adjusted for LDH, CRP, ECOG and number of metastatic sites, the ctDNA remained significant for PFS and OS. A positive correlation was observed between ctDNA levels and total metabolic tumor volume (TMTV), number of metastatic sites and total tumor burden. CONCLUSIONS: Assessment of ctDNA baseline and during therapy was predictive for tumor response and clinical outcome in metastatic melanoma patients and reflected the tumor burden. ctDNA evaluation provided reliable complementary information during anti-PD1 antibody therapy.

Pembrolizumab versus ipilimumab for advanced melanoma: final overall survival results of a multicentre, randomised, open-label phase 3 study (KEYNOTE-006).

BACKGROUND: Interim analyses of the phase 3 KEYNOTE-006 study showed superior overall and progression-free survival of pembrolizumab versus ipilimumab in patients with advanced melanoma. We present the final protocol-specified survival analysis. METHODS: In this multicentre, open-label, randomised, phase 3 trial, we recruited patients from 87 academic institutions, hospitals, and cancer centres in 16 countries (Australia, Austria, Belgium, Canada, Chile, Colombia, France, Germany, Israel, Netherlands, New Zealand, Norway, Spain, Sweden, UK, and USA). We randomly assigned participants (1:1:1) to one of two dose regimens of pembrolizumab, or one regimen of ipilimumab, using a centralised, computer-generated allocation schedule. Treatment assignments used blocked randomisation within strata. Eligible patients were at least 18 years old, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, at least one measurable lesion per Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), unresectable stage III or IV melanoma (excluding ocular melanoma), and up to one previous systemic therapy (excluding anti-CTLA-4, PD-1, or PD-L1 agents). Secondary eligibility criteria are described later. Patients were excluded if they had active brain metastases or active autoimmune disease requiring systemic steroids. The primary outcome was overall survival (defined as the time from randomisation to death from any cause). Response was assessed per RECIST v1.1 by independent central review at week 12, then every 6 weeks up to week 48, and then every 12 weeks thereafter. Survival was assessed every 12 weeks, and final analysis occurred after all patients were followed up for at least 21 months. Primary analysis was done on the intention-to-treat population (all randomly assigned patients) and safety analyses were done in the treated population (all randomly assigned patients who received at least one dose of study treatment). Data cutoff date for this analysis was Dec 3, 2015. This study was registered with ClinicalTrials.gov, number NCT01866319. FINDINGS: Between Sept 18, 2013, and March 3, 2014, 834 patients with advanced melanoma were enrolled and randomly assigned to receive intravenous pembrolizumab every 2 weeks (n=279), intravenous pembrolizumab every 3 weeks (n=277), or intravenous ipilimumab every 3 weeks (ipilimumab for four doses; n=278). One patient in the pembrolizumab 2 week group and 22 patients in the ipilimumab group withdrew consent and did not receive treatment. A total of 811 patients received at least one dose of study treatment. Median follow-up was 22·9 months; 383 patients died. Median overall survival was not reached in either pembrolizumab group and was 16·0 months with ipilimumab (hazard ratio [HR] 0·68, 95% CI 0·53-0·87 for pembrolizumab every 2 weeks vs ipilimumab; p=0·0009 and 0·68, 0·53-0·86 for pembrolizumab every 3 weeks vs ipilimumab; p=0·0008). 24-month overall survival rate was 55% in the 2-week group, 55% in the 3-week group, and 43% in the ipilimumab group. INTERPRETATION: Substantiating the results of the interim analyses of KEYNOTE-006, pembrolizumab continued to provide superior overall survival versus ipilimumab, with no difference between pembrolizumab dosing schedules. These conclusions further support the use of pembrolizumab as a standard of care for advanced melanoma. FUNDING: Merck & Co.

Pembrolizumab versus Ipilimumab in Advanced Melanoma.

BACKGROUND: The immune checkpoint inhibitor ipilimumab is the standard-of-care treatment for patients with advanced melanoma. Pembrolizumab inhibits the programmed cell death 1 (PD-1) immune checkpoint and has antitumor activity in patients with advanced melanoma. METHODS: In this randomized, controlled, phase 3 study, we assigned 834 patients with advanced melanoma in a 1:1:1 ratio to receive pembrolizumab (at a dose of 10 mg per kilogram of body weight) every 2 weeks or every 3 weeks or four doses of ipilimumab (at 3 mg per kilogram) every 3 weeks. Primary end points were progression-free and overall survival. RESULTS: The estimated 6-month progression-free-survival rates were 47.3% for pembrolizumab every 2 weeks, 46.4% for pembrolizumab every 3 weeks, and 26.5% for ipilimumab (hazard ratio for disease progression, 0.58; P<0.001 for both pembrolizumab regimens versus ipilimumab; 95% confidence intervals [CIs], 0.46 to 0.72 and 0.47 to 0.72, respectively). Estimated 12-month survival rates were 74.1%, 68.4%, and 58.2%, respectively (hazard ratio for death for pembrolizumab every 2 weeks, 0.63; 95% CI, 0.47 to 0.83; P=0.0005; hazard ratio for pembrolizumab every 3 weeks, 0.69; 95% CI, 0.52 to 0.90; P=0.0036). The response rate was improved with pembrolizumab administered every 2 weeks (33.7%) and every 3 weeks (32.9%), as compared with ipilimumab (11.9%) (P<0.001 for both comparisons). Responses were ongoing in 89.4%, 96.7%, and 87.9% of patients, respectively, after a median follow-up of 7.9 months. Efficacy was similar in the two pembrolizumab groups. Rates of treatment-related adverse events of grade 3 to 5 severity were lower in the pembrolizumab groups (13.3% and 10.1%) than in the ipilimumab group (19.9%). CONCLUSIONS: The anti-PD-1 antibody pembrolizumab prolonged progression-free survival and overall survival and had less high-grade toxicity than did ipilimumab in patients with advanced melanoma. (Funded by Merck Sharp & Dohme; KEYNOTE-006 ClinicalTrials.gov number, NCT01866319.).

Combination of dabrafenib plus trametinib for BRAF and MEK inhibitor pretreated patients with advanced BRAFV600-mutant melanoma: an open-label, single arm, dual-centre, phase 2 clinical trial.

BACKGROUND: Patients with BRAFV600-mutant melanoma benefit from treatment with the combination of BRAF and MEK inhibitors, but resistance and disease progression develops in most patients. Preclinical studies and case studies have indicated that acquired resistance to BRAF inhibition can be reversible. We aimed to assess the anti-tumour activity of rechallenge with BRAF plus MEK inhibition in a prospective clinical trial. METHODS: In this open-label, single arm, dual-centre, phase 2 academic study in Belgium, patients aged 18 years or older with BRAFV600-mutant melanoma who had previously progressed on BRAF inhibitors (with or without MEK inhibitors) and were off-treatment for at least 12 weeks, were treated with dabrafenib 150 mg orally twice per day plus trametinib 2 mg orally once per day. The primary endpoint was the proportion of patients with investigator-assessed overall response at any time (defined as complete response or partial response according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 confirmed on two occasions, at least 28 days after the first response was recorded). Analyses were done in the intention-to-treat population. The study is ongoing but no longer recruiting patients. This trial is registered with ClinicalTrials.gov, number NCT02296996. FINDINGS: Between April 5, 2014, and Feb 2, 2016, 25 patients were enrolled and initiated treatment in our study. A partial response was documented in eight (32%) of 25 patients (95% CI 15-54; six patients had progressed on previous treatment with dabrafenib plus trametinib and two patients had progressed on previous BRAF inhibitor monotherapy). Stable disease was noted in ten patients (40%; 95% CI 21-61). Rechallenge with dabrafenib plus trametinib was well tolerated. There were no unexpected or grade 4 or 5 treatment-related adverse events. Grade 3 adverse events occurred in two patients (8%; panniculitis [n=1] and pyrexia [n=1]). Serious adverse events which occurred on study were one patient with an Addison crisis triggered by grade 2 pyrexia symptoms that resolved after discontinuation of dabrafenib and trametinib. No patients died as a result of study treatment. INTERPRETATION: Rechallenge with dabrafenib plus trametinib showed anti-tumour activity in patients who had previously progressed on BRAF inhibitors and as such, rechallenge represents a potential new treatment option for these patients. FUNDING: Vlaamse Liga Tegen Kanker, Novartis.

Validated programmed cell death ligand 1 immunohistochemistry assays (E1L3N and SP142) reveal similar immune cell staining patterns in melanoma when using the same sensitive detection system.

AIMS: Tumour cell and/or immune cell programmed cell death ligand 1 (PD-L1) expression is considered as a potential biomarker for anti-PD1 and anti-PD-L1 immunotherapy. Currently, different PD-L1 assays are used. This study aims to compare the staining patterns of two PD-L1 antibody clones in melanoma metastases and correlate them with PD-L1 mRNA expression. METHODS AND RESULTS: The immunohistochemistry assays were optimized and validated independently on a Ventana Benchmark Ultra (Ventana Medical Systems Inc., Tucson, AZ, USA) (E1L3N) and XT (SP142), using the same detection system. In total, 46 melanoma metastases were stained with both validated immunohistochemistry assays. Stained slides were digitized for qualitative and semi-quantitative evaluation; done by pathologist and semi-automated software analysis. A subset of 21 melanoma metastases was selected for quantification of the PD-L1 mRNA expression. Accuracy and precision criteria were met for both assays. PD-L1 protein and mRNA expression showed remarkably good Spearman's coefficients of 0.90 (E1L3N) and 0.87 (SP142). Despite the remarkable correlation between both PD-L1 assays in expression patterns and quantification values (ρ > 0.90), E1L3N showed significantly more tumour cell staining than SP142. CONCLUSIONS: E1L3N and SP142 IHC assays were optimized and validated successfully and independently for sensitive and accurate PD-L1 detection. Concordance was best for immune cell scoring, while E1L3N tended to detect more tumour cells. Determination of the clinically relevant cut-off values for immune cell versus tumour cell detection requires further research.

Disease progression in recurrent glioblastoma patients treated with the VEGFR inhibitor axitinib is associated with increased regulatory T cell numbers and T cell exhaustion.

BACKGROUND: Recurrent glioblastoma is associated with a poor overall survival. Antiangiogenic therapy results in a high tumor response rate but has limited impact on survival. Immunotherapy has emerged as an efficient treatment modality for some cancers, and preclinical evidence indicates that anti-VEGF(R) therapy can counterbalance the immunosuppressive tumor microenvironment. METHODS: We collected peripheral blood mononuclear cells (PBMC) of patients with recurrent glioblastoma treated in a randomized phase II clinical trial comparing the effect of axitinib with axitinib plus lomustine and analyzed the immunophenotype of PBMC, the production of cytokines and expression of inhibitory molecules by circulating T cells. RESULTS: PBMC of 18 patients were collected at baseline and at 6 weeks after initiation of study treatment. Axitinib increased the number of naïve CD8(+) T cells and central memory CD4(+) and CD8(+) T cells and reduced the TIM3 expression on CD4(+) and CD8(+) T cells. Patients diagnosed with progressive disease on axitinib had a significantly increased number of regulatory T cells and an increased level of PD-1 expression on CD4(+) and CD8(+) T cells. In addition, reduced numbers of cytokine-producing T cells were found in progressive patients as compared to patients responding to treatment. CONCLUSION: Our results suggest that axitinib treatment in patients with recurrent glioblastoma has a favorable impact on immune function. At the time of acquired resistance to axitinib, we documented further enhancement of a preexisting immunosuppression. Further investigations on the role of axitinib as potential combination partner with immunotherapy are necessary.

Quantitative assessment of BRAF V600 mutant circulating cell-free tumor DNA as a tool for therapeutic monitoring in metastatic melanoma patients treated with BRAF/MEK inhibitors.

BACKGROUND: BRAF V600 mutant circulating cell-free tumor DNA (BRAF V600mut ctDNA) could serve as a specific biomarker in patients with BRAF V600 mutant melanoma. We analyzed the value of BRAF V600mut ctDNA from plasma as a monitoring tool for advanced melanoma patients treated with BRAF/MEK inhibitors. METHODS: Allele-specific quantitative PCR analysis for BRAF V600 E/E2/D/K/R/M mutations was performed on DNA extracted from plasma of patients with known BRAF V600 mutant melanoma who were treated with dabrafenib and trametinib. RESULTS: 245 plasma samples from 36 patients were analyzed. In 16 patients the first plasma sample was obtained before the first dosing of dabrafenib/trametinib. At baseline, BRAF V600mut ctDNA was detected in 75 % of patients (n = 12/16). BRAF V600mut ctDNA decreased rapidly upon initiation of targeted therapy (p < 0.001) and became undetectable in 60 % of patients (n = 7/12) after 6 weeks of treatment. During treatment, disease progression (PD) was diagnosed in 27 of 36 patients. An increase of the BRAF V600mut ctDNA copy number and fraction, identified PD with a sensitivity of 70 % (n = 19/27) and a specificity of 100 %. An increase in the BRAF V600mut ctDNA fraction was detected prior to clinical PD in 44 % of cases (n = 12/27) and simultaneously with PD in 26 % of patients (n = 7/27). CONCLUSIONS: Quantitative analysis of BRAF V600mut ctDNA in plasma has unique features as a monitoring tool during treatment with BRAF/MEK inhibitors. Its potential as an early predictor of acquired resistance deserves further evaluation.

Molecular and epigenetic features of melanomas and tumor immune microenvironment linked to durable remission to ipilimumab-based immunotherapy in metastatic patients.

BACKGROUND: Ipilimumab (Ipi) improves the survival of advanced melanoma patients with an incremental long-term benefit in 10-15 % of patients. A tumor signature that correlates with this survival benefit could help optimizing individualized treatment strategies. METHODS: Freshly frozen melanoma metastases were collected from patients treated with either Ipi alone (n: 7) or Ipi combined with a dendritic cell vaccine (TriMixDC-MEL) (n: 11). Samples were profiled by immunohistochemistry (IHC), whole transcriptome (RNA-seq) and methyl-DNA sequencing (MBD-seq). RESULTS: Patients were divided in two groups according to clinical evolution: durable benefit (DB; 5 patients) and no clinical benefit (NB; 13 patients). 20 metastases were profiled by IHC and 12 were profiled by RNA- and MBD-seq. 325 genes were identified as differentially expressed between DB and NB. Many of these genes reflected a humoral and cellular immune response. MBD-seq revealed differences between DB and NB patients in the methylation of genes linked to nervous system development and neuron differentiation. DB tumors were more infiltrated by CD8(+) and PD-L1(+) cells than NB tumors. B cells (CD20(+)) and macrophages (CD163(+)) co-localized with T cells. Focal loss of HLA class I and TAP-1 expression was observed in several NB samples. CONCLUSION: Combined analyses of melanoma metastases with IHC, gene expression and methylation profiling can potentially identify durable responders to Ipi-based immunotherapy.

Nivolumab versus chemotherapy in patients with advanced melanoma who progressed after anti-CTLA-4 treatment (CheckMate 037): a randomised, controlled, open-label, phase 3 trial.

BACKGROUND: Nivolumab, a fully human IgG4 PD-1 immune checkpoint inhibitor antibody, can result in durable responses in patients with melanoma who have progressed after ipilimumab and BRAF inhibitors. We assessed the efficacy and safety of nivolumab compared with investigator's choice of chemotherapy (ICC) as a second-line or later-line treatment in patients with advanced melanoma. METHODS: In this randomised, controlled, open-label, phase 3 trial, we recruited patients at 90 sites in 14 countries. Eligible patients were 18 years or older, had unresectable or metastatic melanoma, and progressed after ipilimumab, or ipilimumab and a BRAF inhibitor if they were BRAF(V 600) mutation-positive. Participating investigators randomly assigned (with an interactive voice response system) patients 2:1 to receive an intravenous infusion of nivolumab 3 mg/kg every 2 weeks or ICC (dacarbazine 1000 mg/m(2) every 3 weeks or paclitaxel 175 mg/m(2) combined with carboplatin area under the curve 6 every 3 weeks) until progression or unacceptable toxic effects. We stratified randomisation by BRAF mutation status, tumour expression of PD-L1, and previous best overall response to ipilimumab. We used permuted blocks (block size of six) within each stratum. Primary endpoints were the proportion of patients who had an objective response and overall survival. Treatment was given open-label, but those doing tumour assessments were masked to treatment assignment. We assessed objective responses per-protocol after 120 patients had been treated with nivolumab and had a minimum follow-up of 24 weeks, and safety in all patients who had had at least one dose of treatment. The trial is closed and this is the first interim analysis, reporting the objective response primary endpoint. This study is registered with ClinicalTrials.gov, number NCT01721746. FINDINGS: Between Dec 21, 2012, and Jan 10, 2014, we screened 631 patients, randomly allocating 272 patients to nivolumab and 133 to ICC. Confirmed objective responses were reported in 38 (31·7%, 95% CI 23·5-40·8) of the first 120 patients in the nivolumab group versus five (10·6%, 3·5-23·1) of 47 patients in the ICC group. Grade 3-4 adverse events related to nivolumab included increased lipase (three [1%] of 268 patients), increased alanine aminotransferase, anaemia, and fatigue (two [1%] each); for ICC, these included neutropenia (14 [14%] of 102), thrombocytopenia (six [6%]), and anaemia (five [5%]). We noted grade 3-4 drug-related serious adverse events in 12 (5%) nivolumab-treated patients and nine (9%) patients in the ICC group. No treatment-related deaths occurred. INTERPRETATION: Nivolumab led to a greater proportion of patients achieving an objective response and fewer toxic effects than with alternative available chemotherapy regimens for patients with advanced melanoma that has progressed after ipilimumab or ipilimumab and a BRAF inhibitor. Nivolumab represents a new treatment option with clinically meaningful durable objective responses in a population of high unmet need. FUNDING: Bristol-Myers Squibb.