Project description:Recently, a CTLA-4 antibody and BRAF inhibitors showed survival benefits in advance melanoma treatment. The documentation of immune infiltrates in melanomas early during BRAF inhibitor therapy provides a scientific rationale for combination therapy with both treatments with possible synergistic benefits. This commentary reviews immune responses induced by BRAF inhibitors.
Project description:Metastatic melanoma is one of the most challenging malignancies to treat and often has a poor outcome. Until recently, systemic treatment options were limited, with poor response rates and no survival advantage. However, the treatment of metastatic melanoma has been revolutionized by developments in targeted therapy and immunotherapy; the BRAF inhibitor, vemurafenib, and anticytotoxic T-lymphocyte antigen 4 antibody, ipilimumab, are the first agents to demonstrate a survival benefit. Despite the success of these treatments, most patients eventually progress, and research into response and resistance mechanisms, rationally designed combination therapies and evaluation of the role of these agents in the adjuvant setting is critically important.
Project description:Introduction: Immune checkpoint inhibitor therapy and BRAF-targeted therapy have been developed for the treatment of metastatic melanoma. The optimal use of these agents, either in sequence or combination, for the 40-50% of melanoma patients whose tumors harbor a BRAFV600 mutation is unknown, but data from a number of clinical trials, including one randomized Phase II study, are emerging.Areas covered: This review describes the preclinical and clinical rationale for combined BRAF-targeted therapy with immunotherapy, including the known effects of BRAF-targeted therapy on the immune microenvironment, and the clinical trial data from a number of studies.Expert opinion: BRAF-targeted therapy is associated with high response rates in patients with metastatic melanoma but also leads to changes in the tumor microenvironment that may sensitize these tumors to immunotherapy. The early trials of BRAF-targeted therapy with immunotherapy, in particular with anti-PD-1/PD-L1 agents, are encouraging and suggest that some patients may benefit from this treatment approach. However, incorporating these combinations into routine clinical practice requires the read-out from two randomized clinical trials expected in the coming 1-2 years.
Project description:The incidence of malignant melanoma is increasing. The majority of patients are diagnosed in early stages when the disease is highly curable. However, the more advanced or metastatic cases have always been a challenge for clinicians. The poor prognosis for patients with melanoma is now changing as numerous of promising approaches have appeared recently. The discovery of aberrations of pathways responsible for intracellular signal transduction allowed us to introduce agents specifically targeting the mutated cascades. Numerous clinical studies have been conducted to improve effectiveness of melanoma treatment. From 2011 until now, the U.S. FDA has approved seven novel agents, such as BRAF-inhibitors (vemurafenib 2011, dabrafenib 2013), MEK-inhibitors (trametinib 2013), anti-PD1 antibodies (nivolumab 2014, pembrolizumab 2014), anti-CTLA-4 antibody (ipilimumab 2011), or peginterferon-alfa-2b (2011) intended to be used in most advanced cases of melanoma. Nevertheless, clinicians continue working on new possible methods of treatment as resistance to the novel drugs is a commonly observed problem. This paper is based on latest data published until the end of January 2015.
Project description:Here we present a mouse model for T-cell targeting of hair follicles, linking the pathogenesis of alopecia to that of depigmentation disorders. Clinically, thymus transplantation has been successfully used to treat T-cell immunodeficiency in congenital athymia, but is associated with autoimmunity. We established a mouse model of thymus transplantation by subcutaneously implanting human thymus tissue into athymic C57BL/6 nude mice. These xenografts supported mouse T-cell development. Surprisingly, we did not detect multiorgan autoimmune disease. However, in all transplanted mice, we noted a striking depigmentation and loss of hair follicles. Transfer of T cells from transplanted nudes to syngeneic black-coated RAG(-/-) recipients caused progressive, persistent coat-hair whitening, which preceded patchy hair loss in depigmented areas. Further transfer experiments revealed that these phenomena could be induced by CD4+ T cells alone. Immunofluorescent analysis suggested that Trp2+ melanocyte-lineage cells were decreased in depigmented hair follicles, and pathogenic T cells upregulated activation markers when exposed to C57BL/6 melanocytes in vitro, suggesting that these T cells are not tolerant to self-melanocyte antigens. Our data raise interesting questions about the mechanisms underlying tissue-specific tolerance to skin antigens.
Project description:Very late antigen-4 (VLA-4; also known as integrin α4β1) is expressed at high levels in aggressive and metastatic melanoma tumors and may provide an ideal target for imaging and targeted radionuclide therapy (TRT). 177Lu-DOTA-PEG4-LLP2A (177Lu-LLP2A) is a TRT that shows high affinity for VLA-4 and high uptake in B16F10 mouse melanoma tumors in vivo. Here, we report efficacy studies of 177Lu-LLP2A, alone and combined with immune checkpoint inhibitors (ICIs) (anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies), in B16F10 tumor-bearing mice. Methods: Tumor cells (1 × 106) were implanted subcutaneously in C57BL/6 mice. After 8-10 d, the mice were randomized into 8 groups. 177Lu-LLP2A was injected intravenously on day 8 or 9 (single dose), and ICI antibodies were administered intraperitoneally in 3 doses. Tumor growth was monitored over time via calipers. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining for apoptosis was performed on fixed tumors. In a separate study, Cy3-LLP2A or Cy3-scrambled LLP2A was injected in tumor-bearing mice, and tumors were collected 4 h after injection and then analyzed by flow cytometry and immunofluorescence microscopy using different immune cell markers. Results: TRT alone showed efficacy comparable to the dual-ICI anti-PD-1 + anti-CTLA-4 or anti-PD-L1 + anti-CTLA-4, whereas TRT + ICIs significantly enhanced survival. TUNEL staining showed that the highest levels of apoptosis were in the TRT + ICI groups. In addition to targeting tumor cells, TRT also bound immune cells in the tumor microenvironment. Flow cytometry data showed that the tumors consisted of about 77% tumor cells and fibroblasts (CD45-negative/CD49d-positive) and about 23% immune cells (CD45-positive/CD49d-positive) and that immune cells expressed higher levels of VLA-4. Cy3-LLP2A and CD49d colocalized with macrophages (CD68), T cells (CD8, CD4), and B cells (CD19). Immunohistochemical analysis identified a significant colocalization of Cy3-LLP2A and CD68. Conclusion: Combination treatment with TRT + ICIs targets both tumor cells and immune cells and has potential as a therapeutic agent in patients with metastatic melanoma.
Project description:BackgroundWe aim to provide survival scenario estimates for patients with advanced melanoma starting targeted therapies and immunotherapies.Materials and methodsWe sought randomized trials of targeted therapies and immunotherapies for advanced melanoma and recorded the following percentiles (represented survival scenario) from each overall survival (OS) curve: 90th (worst-case), 75th (lower-typical), 50th (median), 25th (upper-typical), and 10th (best-case). We tested whether these scenarios can be estimated for each OS curve by multiplying its median by 4 multiples: 0.25 (worst-case), 0.5 (lower-typical), 2 (upper-typical), and 3 (best-case).ResultsWe identified 15 trials with 8025 patients. For first-line combination targeted therapy treatment groups, the median (interquartile range, IQR) in months for each percentile was: 90th, 6.2 (6.0-6.5); 75th, 11.3 (11.3-11.4); and median, 24.4 (23.5-25.3). For the first-line combination immunotherapy treatment group, the percentiles in months were: 90th, 3.9 (2.8-4.5); 75th, 13.4 (10.1-15.4), median 73 (not applicable). In targeted therapy groups, simple multiples of the median OS were accurate for estimating the 90th percentile in 80%; 75th percentile in 40%; 25th percentile in 100%. In immunotherapy groups, these multiples were accurate at 0% for the 90th percentile, and 43% for the 75th percentile. The 90th percentile (worst-case scenario) was better estimated as 1/6× median OS, and the 75th percentile (lower-typical) as 1/3× median OS.ConclusionsSimple multiples of the median OS are a useful framework to estimate scenarios for survival for patients receiving targeted therapies, not immunotherapy. Longer follow-up is required to estimate upper-typical and best-case scenarios.
Project description:Immune and BRAF-targeted therapies have changed the therapeutic scenario of advanced melanoma, turning the clinical decision-making a challenging task. This Bayesian network meta-analysis assesses the role of immunotherapies and targeted therapies for advanced melanoma. We retrieved randomized controlled trials testing immune, BRAF- or MEK-targeted therapies for advanced melanoma from electronic databases. A Bayesian network model compared therapies using hazard ratio (HR) for overall survival (OS), progression-free survival (PFS), and odds ratio (OR) for response rate (RR), along with 95% credible intervals (95% CrI), and probabilities of drugs outperforming others. We assessed the impact of PD-L1 expression on immunotherapy efficacy. Sixteen studies evaluating eight therapies in 6849 patients were analyzed. For OS, BRAF-MEK combination and PD-1 single agent ranked similarly and outperformed all other treatments. For PFS, BRAF-MEK combination surpassed all other options, including CTLA-4-PD-1 dual blockade hazard ratio (HR: 0.56; 95% CrI: 0.33-0.97; probability better 96.2%), whereas BRAF single agent ranked close to CTLA-4-PD-1 blockade. For RR, BRAF-MEK combination was superior to all treatments including CTLA-4-PD-1 (OR: 2.78; 1.18-6.30; probability better 97.1%). No OS data were available for CTLA-4-PD-1 blockade at the time of systematic review, although PFS and RR results suggested that this combination could also bring meaningful benefit. PD-L1 expression, as presently defined, failed to inform patient selection to PD-1-based immunotherapy. BRAF-MEK combination seemed an optimal therapy for BRAF-mutated patients, whereas PD-1 inhibitors seemed optimal for BRAF wild-type patients. Longer follow-up is needed to ascertain the role of CTLA-4-PD-1 blockade. Immunotherapy biomarkers remain as an unmet need.
Project description:BackgroundCytotoxic chemotherapy (CC) is currently used in metastatic melanoma after patients have developed resistance to immune checkpoint inhibitors (ICI) and/or Mitogen-Activated Protein Kinase inhibitors (MAPKi). We sought to evaluate if a previous treatment by ICI or MAPKi influences clinical outcomes in patients treated by CC in metastatic melanoma.MethodsEighty-eight patients with a metastatic melanoma, treated by CC after a previous treatment by ICI or MAPKi between January 2009 and October 2019, were retrospectively analyzed. Progression-Free-Survival (PFS), Overall Survival (OS), Overall Response Rate (ORR), and Disease Control Rate (DCR) were evaluated in patients treated by CC according to their prior treatment by ICI or MAPKi.ResultsPatients treated by CC after ICI tended to have a better median PFS (2.81 months (2.39-5.30) versus 2.40 months (0.91-2.75), p = 0.023), median OS (6.03 months (3.54-11.54) versus 4.44 months (1.54-8.59), p = 0.27), DCR (26.0% vs. 10.5%, p = 0.121) and ORR (22.0% vs. 7.9% p = 0.134) than those previously treated by MAPKi.ConclusionsA prior treatment by an MAPKi may be associated with a worse response to CC than ICI, and further investigations should be performed to confirm if there is a clinical benefit to propose CC in this setting.
Project description:Opinion statementMelanoma has several clinically and pathologically distinguishable subtypes, which also differ genetically. Mutation patterns vary among different melanoma subtypes, and efficacy of immune-checkpoint inhibitors differs depending on the subtype of melanoma. In spite of the recent revolution of systemic therapies for advanced melanoma, access to innovative agents is still restricted in many countries. This review article aimed to describe the epidemiology and current status of systemic therapies for melanoma in Japan, where melanoma is rare, but access to innovative agents is available. Acral and mucosal melanomas, which are common in Asian populations, predominantly occur in sun-protected areas and share several biological features. Both the melanomas harbor KIT mutation in approximately 15% of the cases; BRAF or NRAS mutation is found in approximately 10-15% of acral melanoma, but these mutations are less frequent in mucosal melanoma. Combined use of BRAF and MEK inhibitors is one of the standards of care for patients with advanced BRAF-mutant melanoma. In patients with melanoma harboring KIT mutation in exon 11 or 13, KIT inhibitors can be a treatment option; however, none of them have been approved in Japan. Immune-checkpoint inhibitors are expected to be less effective against acral and mucosal melanomas because their somatic mutation burden is lower than those in non-acral cutaneous melanomas. A recently completed phase II trial of nivolumab and ipilimumab combination therapy in 30 Japanese patients with melanoma, including seven with acral and 12 with mucosal melanoma, demonstrated an objective response rate of 43%. Regarding oncolytic viruses, canerpaturev (C-REV, also known as HF10) and talimogene laherparepvec (T-VEC) are currently under review in early phase trials. In the adjuvant setting, dabrafenib plus trametinb combination, nivolumab monotherapy, and pembrolizumab monotherapy were approved in July, August, and December 2018 in Japan, respectively. However, most of the adjuvant phase III trials excluded patients with mucosal melanoma. A phase III trial of adjuvant therapy with locoregional interferon (IFN)-β versus surgery alone is ongoing in Japan (JCOG1309, J-FERON), in which IFN-β is injected directly into the site of the primary tumor postoperatively, so that it would be drained through the untreated lymphatic route to the regional node basin. After the recent approval of these new agents, the JCOG1309 trial will be revised to focus on patients with stage II disease. In conclusion, acral and mucosal melanomas have been treated based on the available medical evidence for the treatment of non-acral cutaneous melanomas. Considering the differences in genetic backgrounds and therapeutic efficacy of immunotherapy, specialized therapeutic strategies for these subtypes of melanoma should be established in the future.