10041 Background: Predictors of outcomes of immune checkpoint inhibitors (ICI) are desirable. We aim to investigate the prognostic value of 18F-fluorodeoxyglucose-PET/CT (FDG-PET) parameters at baseline and response monitoring of patients (pts) with advanced melanoma receiving ipi/nivo. Methods: From 2016-2019, melanoma pts who received ipi/nivo and had PET Response Criteria In Solid Tumors (PERCIST) measurable lesions on baseline FDG-PET were included. Baseline whole-body metabolic tumor volume (wbMTV), tumor stage, mutational status, ECOG performance score, lactate dehydrogenase (LDH) and treatment-line were correlated with overall survival (OS) in univariate and multivariate Cox-regression analysis. Response were assessed for a subset of pts with post-treatment FDG-PET based on PERCIST. Results: Of 162 pts receiving ipi/nivo, 122 pts (median age: 61; male: 73%; ECOG 0: 78%; raised LDH: 52%; M1c: 39%, M1d: 45% and BRAFV600E/Kmutation: 45%) met eligibility criteria. Forty percent received ipi/nivo as first-line treatment, 48% as second-line (25% post BRAF inhibitor(i)/MEKi and 23% post single-agent ICI) and 12% as third-line. At median follow-up of 21 months (mths), median OS was 20 mths (95% CI 11-not reached[NR]). Pts with above the median wbMTV had shorter OS than those with below the median wbMTV (NR vs 10 mths, 95% CI 8-NR; HR 2.0, 95% CI 1.2-3.4, p = 0.009). In multivariate analysis, wbMTV, ECOG and treatment-line were independently associated with OS. In 106 pts with post-treatment FDG-PET, 24 mths OS rate was higher for those with objective response (OR): 91% (95% CI 82-100%) vs stable disease:55% (27-100%) vs progressive disease:17% (8-35%) as best response, p < 0.001. OR was higher in first-line compared to second or third-line treatment, 75% vs 29-33% vs 23%, respectively, p = 0.0012. Conclusions: Increased baseline FDG-PET wbMTV is an independent prognostic biomarker in pts with advanced melanoma receiving ipi/nivo. FDG-PET response accurately predicts outcome. [Table: see text]

PURPOSE:The CheckMate 066 trial investigated nivolumab monotherapy as first-line treatment for patients with previously untreated BRAF wild-type advanced melanoma. Five-year results are presented herein.PATIENTS AND METHODS:In this multicenter, double-blind, phase III study, 418 patients with previously untreated, unresectable, stage III/IV, wild-type BRAF melanoma were randomly assigned 1:1 to receive nivolumab 3 mg/kg every 2 weeks or dacarbazine 1,000 mg/m2 every 3 weeks. The primary end point was overall survival (OS), and secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.RESULTS:Patients were followed for a minimum of 60 months from the last patient randomly assigned (median follow-up, 32.0 months for nivolumab and 10.9 months for dacarbazine). Five-year OS rates were 39% with nivolumab and 17% with dacarbazine; PFS rates were 28% and 3%, respectively. Five-year OS was 38% in patients randomly assigned to dacarbazine who had subsequent therapy, including nivolumab (n = 37). ORR was 42% with nivolumab and 14% with dacarbazine; among patients alive at 5 years, ORR was 81% and 39%, respectively. Of 42 patients treated with nivolumab who had a complete response (20%), 88% (37 of 42) were alive as of the 5-year analysis. Among 75 nivolumab-treated patients alive and evaluable at the 5-year analysis, 83% had not received subsequent therapy; 23% were still on study treatment, and 60% were treatment free. Safety analyses were similar to the 3-year report.CONCLUSION:Results from this 5-year analysis confirm the significant benefit of nivolumab over dacarbazine for all end points and add to the growing body of evidence supporting long-term survival with nivolumab mono-therapy. Survival is strongly associated with achieving a durable response, which can be maintained after treatment discontinuation, even without subsequent systemic therapies.

IMPORTANCE:Rheumatic immune-related adverse events (irAEs) occur in approximately 10-20% of anti-programmed death 1 (anti-PD1)-treated cancer patients. There are limited data on the natural history, optimal treatment and long-term oncological outcomes of patients with rheumatic irAEs. OBJECTIVE:The objective of the study was to describe the spectrum and natural history of rheumatic irAEs and the potential impact of rheumatic irAEs and immunomodulators on anti-PD1 tumour efficacy. METHODS:Cancer patients with pre-existing rheumatic disease before anti-PD1 therapy or de novo rheumatic irAEs on anti-PD1 therapy were retrospectively reviewed across three sites. Patient demographics, treatment history, anti-PD1 irAEs, and anti-PD1 responses were evaluated. Relationships between the development or pre-existence of rheumatic irAE, use of immunomodulatory agents and outcomes were evaluated. RESULTS:This multicenter case series describes 36 cancer patients who had rheumatic disease before anti-PD1 therapy (n = 12) or developed de novo rheumatic irAEs (n = 24). Thirty-four of the 36 patients sustained rheumatic irAEs (median time to rheumatic irAE: 14.5 weeks), including 24 de novo (18 inflammatory arthritis, three myositis, two polymyalgia rheumatica, one fasciitis) and 10 flares in 12 patients with pre-existing rheumatic disease. Corticosteroids were used in 30 of 36 patients (median duration: 10 months), and disease-modifying antirheumatic drugs were used in 14 of 36 patients (median duration: 5.5 months). The objective response rate to anti-PD1 therapy was 69% (n = 25/36) overall and 81% (n = 21/26) in the melanoma subgroup. CONCLUSIONS:Rheumatic irAEs are often chronic and require prolonged immunomodulatory therapy. Prospective studies are required to define optimal management of rheumatic irAEs that maintain long-term anticancer outcomes.

IMPORTANCE This analysis provides long-term follow-up in patients with BRAF wild-type advanced melanoma receiving first-line therapy based on anti-programmed cell death 1 receptor inhibitors. OBJECTIVE To compare the 3-year survival with nivolumab vs that with dacarbazine in patients with previously untreated BRAF wild-type advanced melanoma. DESIGN, SETTING, AND PARTICIPANTS This follow-up of a randomized phase 3 trial analyzed 3-year overall survival data from the randomized, controlled, double-blind CheckMate 066 phase 3 clinical trial. For this ongoing, multicenter academic institution trial, patients were enrolled from January 2013 through February 2014. Eligible patients were 18 years or older with confirmed unresectable previously untreated stage III or IV melanoma and an Eastern Cooperative Oncology Group performance status of 0 or 1 but without a BRAF mutation. INTERVENTIONS Patients were treated until progression or unacceptable toxic events with nivolumab (3 mg/kg every 2 weeks plus dacarbazine-matched placebo every 3 weeks) or dacarbazine (1000 mg/m(2) every 3 weeks plus nivolumab-matched placebo every 2 weeks). MAIN OUTCOME AND MEASURE Overall survival. RESULTS At minimum follow-ups of 38.4 months among 210 participants in the nivolumab group (median age, 64 years [range, 18-86 years]; 57.6% male) and 38.5 months among 208 participants in the dacarbazine group (median age, 66 years [range, 25-87 years]; 60.1% male), 3-year overall survival rates were 51.2% (95% CI, 44.1%-57.9%) and 21.6% (95% CI, 16.1%-27.6%), respectively. The median overall survival was 37.5 months (95% CI, 25.5 months-not reached) in the nivolumab group and 11.2 months (95% CI, 9.6-13.0 months) in the dacarbazine group (hazard ratio, 0.46; 95% CI, 0.36-0.59; P < .001). Complete and partial responses, respectively, were reported for 19.0% (40 of 210) and 23.8% (50 of 210) of patients in the nivolumab group compared with 1.4% (3 of 208) and 13.0% (27 of 208) of patients in the dacarbazine group. Additional analyses were performed on outcomes with subsequent therapies. Treatment-related grade 3/4 adverse events occurred in 15.0% (31 of 206) of nivolumab-treated patients and in 17.6% (36 of 205) of dacarbazine-treated patients. There were no deaths due to study drug toxic effects. CONCLUSIONS AND RELEVANCE Nivolumab led to improved 3-year overall survival vs dacarbazine in patients with previously untreated BRAF wild-type advanced melanoma.

PURPOSECirculating tumor DNA (ctDNA) allows noninvasive disease monitoring across a range of malignancies. In metastatic melanoma, the extent to which ctDNA reflects changes in metabolic disease burden assessed by 18F-labeled fluorodeoxyglucose positron emission tomography (FDG-PET) is unknown. We assessed the role of ctDNA analysis in combination with FDG-PET to monitor tumor burden and genomic heterogeneity throughout treatment.PATIENTS AND METHODSWe performed a comprehensive analysis of serial ctDNA and FDG-PET in 52 patients who received systemic therapy for metastatic melanoma. Next-generation sequencing and digital polymerase chain reaction were used to analyze plasma samples from the cohort.RESULTSctDNA levels were monitored across patients with mutant BRAF, NRAS, and BRAF/NRAS wild type disease. Mutant BRAF and NRAS ctDNA levels correlated closely with changes in metabolic disease burden throughout treatment. TERT promoter mutant ctDNA levels also paralleled changes in tumor burden, which provide an alternative marker for disease monitoring. Of note, subcutaneous and cerebral disease sites were not well represented in plasma. Early changes in ctDNA and metabolic disease burden were important indicators of treatment response. Patients with an early decrease in ctDNA post-treatment had improved progression-free survival compared with patients in whom ctDNA levels remained unchanged or increased over time (hazard ratio, 2.6; P = .05). ctDNA analysis contributed key molecular information through the identification of putative resistance mechanisms to targeted therapy. A detailed comparison of the genomic architecture of plasma and multiregional tumor biopsy specimens at autopsy revealed the ability of ctDNA to comprehensively capture genomic heterogeneity across multiple disease sites.CONCLUSIONThe findings highlight the powerful role of ctDNA in metastatic melanoma as a complementary modality to functional imaging that allows real-time monitoring of both tumor burden and genomic changes throughout therapy.

Purpose Mucosal melanoma is an aggressive malignancy with a poor response to conventional therapies. The efficacy and safety of nivolumab (a programmed death-1 checkpoint inhibitor), alone or combined with ipilimumab (a cytotoxic T-lymphocyte antigen-4 checkpoint inhibitor), have not been reported in this rare melanoma subtype. Patients and Methods Data were pooled from 889 patients who received nivolumab monotherapy in clinical studies, including phase III trials; 86 (10%) had mucosal melanoma and 665 (75%) had cutaneous melanoma. Data were also pooled for patients who received nivolumab combined with ipilimumab (n = 35, mucosal melanoma; n = 326, cutaneous melanoma). Results Among patients who received nivolumab monotherapy, median progression-free survival was 3.0 months (95% CI, 2.2 to 5.4 months) and 6.2 months (95% CI, 5.1 to 7.5 months) for mucosal and cutaneous melanoma, with objective response rates of 23.3% (95% CI, 14.8% to 33.6%) and 40.9% (95% CI, 37.1% to 44.7%), respectively. Median progression-free survival in patients treated with nivolumab combined with ipilimumab was 5.9 months (95% CI, 2.8 months to not reached) and 11.7 months (95% CI, 8.9 to 16.7 months) for mucosal and cutaneous melanoma, with objective response rates of 37.1% (95% CI, 21.5% to 55.1%) and 60.4% (95% CI, 54.9% to 65.8%), respectively. For mucosal and cutaneous melanoma, respectively, the incidence of grade 3 or 4 treatment-related adverse events was 8.1% and 12.5% for nivolumab monotherapy and 40.0% and 54.9% for combination therapy. Conclusion To our knowledge, this is the largest analysis of data for anti-programmed death-1 therapy in mucosal melanoma to date. Nivolumab combined with ipilimumab seemed to have greater efficacy than either agent alone, and although the activity was lower in mucosal melanoma, the safety profile was similar between subtypes.

Table of contents MELANOMA BRIDGE 2015 KEYNOTE SPEAKER PRESENTATIONS Molecular and immuno-advances K1 Immunologic and metabolic consequences of PI3K/AKT/mTOR activation in melanoma Vashisht G. Y. Nanda, Weiyi Peng, Patrick Hwu, Michael A. Davies K2 Non-mutational adaptive changes in melanoma cells exposed to BRAF and MEK inhibitors help the establishment of drug resistance Gennaro Ciliberto, Luigi Fattore, Debora Malpicci, Luigi Aurisicchio, Paolo Antonio Ascierto, Carlo M. Croce, Rita Mancini K3 Tumor-intrinsic beta-catenin signaling mediates tumor-immune avoidance Stefani Spranger, Thomas F. Gajewski K4 Intracellular tumor antigens as a source of targets of antibody-based immunotherapy of melanoma Yangyang Wang, Soldano Ferrone Combination therapies K5 Harnessing radiotherapy to improve responses to immunotherapy in cancer Claire Vanpouille-Box, Erik Wennerberg, Karsten A. Pilones, Silvia C. Formenti, Sandra Demaria K6 Creating a T cell-inflamed tumor microenvironment overcomes resistance to checkpoint blockade Haidong Tang, Yang Wang, Yang-Xin Fu K7 Biomarkers for treatment decisions? Reinhard Dummer K8 Combining oncolytic therapies in the era of checkpoint inhibitors Igor Puzanov K9 Immune checkpoint blockade for melanoma: should we combine or sequence ipilimumab and PD-1 antibody therapy? Michael A. Postow News in immunotherapy K10 An update on adjuvant and neoadjuvant therapy for melanom Ahmad Tarhini K11 Targeting multiple inhibitory receptors in melanoma Joe-Marc Chauvin, Ornella Pagliano, Julien Fourcade, Zhaojun Sun, Hong Wang, Cindy Sanders, John M. Kirkwood, Tseng-hui Timothy Chen, Mark Maurer, Alan J. Korman, Hassane M. Zarour K12 Improving adoptive immune therapy using genetically engineered T cells David F. Stroncek Tumor microenvironment and biomarkers K13 Myeloid cells and tumor exosomes: a crosstalk for assessing immunosuppression? Veronica Huber, Licia Rivoltini K14 Update on the SITC biomarker taskforce: progress and challenges Magdalena Thurin World-wide immunoscore task force: an update K15 The immunoscore in colorectal cancer highlights the importance of digital scoring systems in surgical pathology Tilman Rau, Alessandro Lugli K16 The immunoscore: toward an integrated immunomonitoring from the diagnosis to the follow up of cancer’s patients Franck Pagès Economic sustainability of melanoma treatments: regulatory, health technology assessment and market access issues K17 Nivolumab, the regulatory experience in immunotherapy Jorge Camarero, Arantxa Sancho K18 Evidence to optimize access for immunotherapies Claudio Jommi ORAL PRESENTATIONS Molecular and immuno-advances O1 Ipilimumab treatment results in CD4 T cell activation that is concomitant with a reduction in Tregs and MDSCs Yago Pico de Coaña, Maria Wolodarski, Yuya Yoshimoto, Giusy Gentilcore, Isabel Poschke, Giuseppe V. Masucci, Johan Hansson, Rolf Kiessling O2 Evaluation of prognostic and therapeutic potential of COX-2 and PD-L1 in primary and metastatic melanoma Giosuè Scognamiglio, Francesco Sabbatino, Federica Zito Marino, Anna Maria Anniciello, Monica Cantile, Margherita Cerrone, Stefania Scala, Crescenzo D’alterio, Angela Ianaro, Giuseppe Cirino, Paolo Antonio Ascierto, Giuseppina Liguori, Gerardo Botti O3 Vemurafenib in patients with BRAFV600 mutation–positive metastatic melanoma: final overall survival results of the BRIM-3 study Paul B. Chapman, Caroline Robert, James Larkin, John B. Haanen, Antoni Ribas, David Hogg, Omid Hamid, Paolo Antonio Ascierto, Alessandro Testori, Paul Lorigan, Reinhard Dummer, Jeffrey A. Sosman, Keith T. Flaherty, Huibin Yue, Shelley Coleman, Ivor Caro, Axel Hauschild, Grant A. McArthur O4 Updated survival, response and safety data in a phase 1 dose-finding study (CA209-004) of concurrent nivolumab (NIVO) and ipilimumab (IPI) in advanced melanoma Mario Sznol, Margaret K. Callahan, Harriet Kluger, Michael A. Postow, RuthAnn Gordan, Neil H. Segal, Naiyer A. Rizvi, Alexander Lesokhin, Michael B. Atkins, John M. Kirkwood, Matthew M. Burke, Amanda Ralabate, Angel Rivera, Stephanie A. Kronenberg, Blessing Agunwamba, Mary Ruisi, Christine Horak, Joel Jiang, Jedd Wolchok Combination therapies O5 Efficacy and correlative biomarker analysis of the coBRIM study comparing cobimetinib (COBI) + vemurafenib (VEM) vs placebo (PBO) + VEM in advanced BRAF-mutated melanoma patients (pts) Paolo A. Ascierto, Grant A. McArthur, James Larkin, Gabriella Liszkay, Michele Maio, Mario Mandalà, Lev Demidov, Daniil Stoyakovskiy, Luc Thomas, Luis de la Cruz-Merino, Victoria Atkinson, Caroline Dutriaux, Claus Garbe, Matthew Wongchenko, Ilsung Chang, Daniel O. Koralek, Isabelle Rooney, Yibing Yan, Antoni Ribas, Brigitte Dréno O6 Preliminary clinical safety, tolerability and activity results from a Phase Ib study of atezolizumab (anti-PDL1) combined with vemurafenib in BRAFV600-mutant metastatic melanoma Ryan Sullivan, Omid Hamid, Manish Patel, Stephen Hodi, Rodabe Amaria, Peter Boasberg, Jeffrey Wallin, Xian He, Edward Cha, Nicole Richie, Marcus Ballinger, Patrick Hwu O7 Preliminary safety and efficacy data from a phase 1/2 study of epacadostat (INCB024360) in combination with pembrolizumab in patients with advanced/metastatic melanoma Thomas F. Gajewski, Omid Hamid, David C. Smith, Todd M. Bauer, Jeffrey S. Wasser, Jason J. Luke, Ani S. Balmanoukian, David R. Kaufman, Yufan Zhao, Janet Maleski, Lance Leopold, Tara C. Gangadhar O8 Primary analysis of MASTERKEY-265 phase 1b study of talimogene laherparepvec (T-VEC) and pembrolizumab (pembro) for unresectable stage IIIB-IV melanoma Reinhard Dummer, Georgina V. Long, Antoni Ribas, Igor Puzanov, Olivier Michielin, Ari VanderWalde, Robert H.I. Andtbacka, Jonathan Cebon, Eugenio Fernandez, Josep Malvehy, Anthony J. Olszanski, Thomas F. Gajewski, John M. Kirkwood, Christine Gause, Lisa Chen, David R. Kaufman, Jeffrey Chou, F. Stephen Hodi News in immunotherapy O9 Two-year survival and safety update in patients (pts) with treatment-naïve advanced melanoma (MEL) receiving nivolumab (NIVO) or dacarbazine (DTIC) in CheckMate 066 Victoria Atkinson, Paolo A. Ascierto, Georgina V. Long, Benjamin Brady, Caroline Dutriaux, Michele Maio, Laurent Mortier, Jessica C. Hassel, Piotr Rutkowski, Catriona McNeil, Ewa Kalinka-Warzocha, Celeste Lebbé, Lars Ny, Matias Chacon, Paola Queirolo, Carmen Loquai, Parneet Cheema, Alfonso Berrocal, Karmele Mujika Eizmendi, Luis De La Cruz-Merino, Gil Bar-Sela, Christine Horak, Joel Jiang, Helene Hardy, Caroline Robert O10 Efficacy and safety of nivolumab (NIVO) in patients (pts) with advanced melanoma (MEL) who were treated beyond progression in CheckMate 066/067 Georgina V. Long, Jeffrey S. Weber, James Larkin, Victoria Atkinson, Jean-Jacques Grob, Reinhard Dummer, Caroline Robert, Ivan Marquez-Rodas, Catriona McNeil, Henrik Schmidt, Karen Briscoe, Jean-François Baurain, F. Stephen Hodi, Jedd D. Wolchok Tumor microenvironment and biomarkers O11 New biomarkers for response/resistance to BRAF inhibitor therapy in metastatic melanoma Rosamaria Pinto, Simona De Summa, Vito Michele Garrisi, Sabino Strippoli, Amalia Azzariti, Gabriella Guida, Michele Guida, Stefania Tommasi O12 Chemokine receptor patterns in lymphocytes mirror metastatic spreading in melanoma and response to ipilimumab Nicolas Jacquelot, David Enot, Caroline Flament, Jonathan M. Pitt, Nadège Vimond, Carolin Blattner, Takahiro Yamazaki, Maria-Paula Roberti, Marie Vetizou, Romain Daillere, Vichnou Poirier-Colame, Michaëla Semeraro, Anne Caignard, Craig L Slingluff Jr, Federica Sallusto, Sylvie Rusakiewicz, Benjamin Weide, Aurélien Marabelle, Holbrook Kohrt, Stéphane Dalle, Andréa Cavalcanti, Guido Kroemer, Anna Maria Di Giacomo, Michaele Maio, Phillip Wong, Jianda Yuan, Jedd Wolchok, Viktor Umansky, Alexander Eggermont, Laurence Zitvogel O13 Serum levels of PD1- and CD28-positive exosomes before Ipilimumab correlate with therapeutic response in metastatic melanoma patients Passarelli Anna, Tucci Marco, Stucci Stefania, Mannavola Francesco, Capone Mariaelena, Madonna Gabriele, Ascierto Paolo Antonio, Silvestris Franco O14 Immunological prognostic factors in stage III melanomas María Paula Roberti, Nicolas Jacquelot, David P Enot, Sylvie Rusakiewicz, Michaela Semeraro, Sarah Jégou, Camila Flores, Lieping Chen, Byoung S. Kwon, Ana Carrizossa Anderson, Caroline Robert, Christophe Borg, Benjamin Weide, François Aubin, Stéphane Dalle, Michele Maio, Jedd D. Wolchok, Holbrook Kohrt, Maha Ayyoub, Guido Kroemer, Aurélien Marabelle, Andréa Cavalcanti, Alexander Eggermont, Laurence Zitvogel POSTER PRESENTATIONS Molecular and immuno-advances P1 Human melanoma cells resistant to B-RAF and MEK inhibition exhibit mesenchymal-like features Anna Lisa De Presbiteris, Fabiola Gilda Cordaro, Rosa Camerlingo, Federica Fratangelo, Nicola Mozzillo, Giuseppe Pirozzi, Eduardo J. Patriarca, Paolo A. Ascierto, Emilia Caputo P2 Anti-proliferative and pro-apoptotic effect of ABT888 on melanoma cell lines and its potential role in the treatment of melanoma resistant to B-RAF inhibitors Federica Fratangelo, Rosa Camerlingo, Emilia Caputo, Maria Letizia Motti, Rosaria Falcone, Roberta Miceli, Mariaelena Capone, Gabriele Madonna, Domenico Mallardo, Maria Vincenza Carriero, Giuseppe Pirozzi and Paolo Antonio Ascierto P3 Involvement of the L-cysteine/CSE/H2S pathway in human melanoma progression Elisabetta Panza, Paola De Cicco, Chiara Armogida, Giuseppe Ercolano, Rosa Camerlingo, Giuseppe Pirozzi, Giosuè Scognamiglio, Gerardo Botti, Giuseppe Cirino, Angela Ianaro P4 Cancer stem cell antigen revealing pattern of antibody variable region genes were defined by immunoglobulin repertoire analysis in patients with malignant melanoma Beatrix Kotlan, Gabriella Liszkay, Miri Blank, Timea Balatoni, Judit Olasz, Emil Farkas, Andras Szollar, Akos Savolt, Maria Godeny, Orsolya Csuka, Szabolcs Horvath, Klara Eles, Yehuda Shoenfeld and Miklos Kasler P5 Upregulation of Neuregulin-1 expression is a hallmark of adaptive response to BRAF/MEK inhibitors in melanoma Debora Malpicci, Luigi Fattore, Susan Costantini, Francesca Capone, Paolo Antonio Ascierto, Rita Mancini, Gennaro Ciliberto P6 HuR positively regulates migration of HTB63 melanoma cells Farnaz Moradi, Pontus Berglund, Karin Leandersson, Rickard Linnskog, Tommy Andersson, Chandra Prakash Prasad P7 Prolyl 4- (C-P4H) hydroxylases have opposing effects in malignant melanoma: implication in prognosis and therapy Cristiana Lo Nigro, Laura Lattanzio, Hexiao Wang, Charlotte Proby, Nelofer Syed, Marcella Occelli, Carolina Cauchi, Marco Merlano, Catherine Harwood, Alastair Thompson, Tim Crook P8 Urokinase receptor antagonists: novel agents for the treatment of melanoma Maria Letizia Motti, Katia Bifulco, Vincenzo Ingangi, Michele Minopoli, Concetta Ragone, Federica Fratangelo, Antonello Pessi, Gennaro Ciliberto, Paolo Antonio Ascierto, Maria Vincenza Carriero P9 Exosomes released by melanoma cell lines enhance chemotaxis of primary tumor cells Francesco Mannavola, Stella D’Oronzo, Claudia Felici, Marco Tucci, Antonio Doronzo, Franco Silvestris P10 New insights in mitochondrial metabolic reprogramming in melanoma Anna Ferretta, Gabriella Guida, Stefania Guida, Imma Maida, Tiziana Cocco, Sabino Strippoli, Stefania Tommasi, Amalia Azzariti, Michele Guida P11 Lenalidomide restrains the proliferation in melanoma cells through a negative regulation of their cell cycle Stella D’Oronzo, Anna Passarelli, Claudia Felici, Marco Tucci, Davide Quaresmini, Franco Silvestris Combination therapies P12 Chemoimmunotherapy elicits polyfunctional anti-tumor CD8 + T cells depending on the activation of an AKT pathway sustained by ICOS Ornella Franzese, Belinda Palermo, Cosmo Di Donna, Isabella Sperduti, MariaLaura Foddai, Helena Stabile, Angela Gismondi, Angela Santoni, Paola Nisticò P13 Favourable toxicity profile of combined BRAF and MEK inhibitors in metastatic melanoma patients Andrea P. Sponghini, Francesca Platini, Elena Marra, David Rondonotti, Oscar Alabiso, Maria T. Fierro, Paola Savoia, Florian Stratica, Pietro Quaglino P14 Electrothermal bipolar vessel sealing system dissection reduces seroma output or time to drain removal following axillary and ilio-inguinal node dissection in melanoma patients: a pilot study Di Monta Gianluca, Caracò Corrado, Di Marzo Massimiliano, Marone Ugo, Di Cecilia Maria Luisa, Mozzillo Nicola News in immunotherapy P15 Clinical and immunological response to ipilimumab in a metastatic melanoma patient with HIV infection Francesco Sabbatino, Celeste Fusciello1, Antonio Marra, Rosario Guarrasi, Carlo Baldi, Rosa Russo, Di Giulio Giovanni, Vincenzo Faiola, Pio Zeppa, Stefano Pepe P16 Immunotherapy and hypophysitis: a case report Elisabetta Gambale, Consiglia Carella, Alessandra Di Paolo, Michele De Tursi Tumor microenvironment and biomarkers P17 New immuno- histochemical markers for the differential diagnosis of atypical melanocytic lesions with uncertain malignant potential Laura Marra, Giosuè Scognamiglio, Monica Cantile, Margherita Cerrone, Fara De Murtas, Valeria Sorrentino, Anna Maria Anniciello, Gerardo Botti P18 Utility of simultaneous measurement of three serum tumor markers in melanoma patients Angela Sandru, Silviu Voinea, Eugenia Panaitescu, Madalina Bolovan, Adina Stanciu, Sabin Cinca P19 The significance of various cut-off levels of melanoma inhibitory activity in evaluation of cutaneous melanoma patients Angela Sandru, Silviu Voinea, Eugenia Panaitescu, Madalina Bolovan, Adina Stanciu, Sabin Cinca P20 The long noncoding RNA HOTAIR is associated to metastatic progression of melanoma and it can be identified in the blood of patients with advanced disease Chiara Botti, Giosuè Scognamiglio, Laura Marra, Gabriella Aquino, Rosaria Falcone, Annamaria Anniciello, Paolo Antonio Ascierto, Gerardo Botti, Monica Cantile Other P21 The effect of Sentinel Lymph Node Biopsy in melanoma mortality: timing of dissection Cristina Fortes, Simona Mastroeni, Alessio Caggiati, Francesca Passarelli, Alba Zappalà, Maria Capuano, Riccardo Bono, Maurizio Nudo, Claudia Marino, Paola Michelozzi P22 Epidemiological survey on related psychopathology in melanoma Valeria De Biasio, Vincenzo C. Battarra IMMUNOTHERAPY BRIDGE KEYNOTE SPEAKER PRESENTATIONS Immunotherapy beyond melanoma K19 Predictor of response to radiation and immunotherapy Silvia Formenti K20 Response and resistance to PD-1 pathway blockade: clues from the tumor microenvironment Maria Libera Ascierto, Tracee L. McMiller, Alan E. Berger, Ludmila Danilova, Robert A. Anders, George J. Netto, Haiying Xu, Theresa S. Pritchard, Jinshui Fan, Chris Cheadle, Leslie Cope, Charles G. Drake, Drew M. Pardoll, Janis M. Taube and Suzanne L. Topalian K21 Combination immunotherapy with autologous stem cell transplantation, protein immunization, and PBMC reinfusion in myeloma patients Sacha Gnjatic, Sarah Nataraj, Naoko Imai, Adeeb Rahman, Achim A. Jungbluth, Linda Pan, Ralph Venhaus, Andrew Park, Frédéric F. Lehmann, Nikoletta Lendvai, Adam D. Cohen, and Hearn J. Cho K22 Anti-cancer immunity despite T cell “exhaustion” Speiser Daniel Immunotherapy in oncology (I-O): data from clinical trial K23 The Checkpoint Inhibitors for the Treatment of Metastatic Non-small Cell Lung Cancer (NSCLC) Vera Hirsh

BRAF mutations occur commonly in metastatic melanomas and inhibition of mutant BRAF and the downstream kinase MEK results in rapid tumor regression and prolonged survival in patients. Combined therapy with BRAF and MEK inhibition improves response rate, progression free survival and overall survival compared with single agent BRAF inhibition, and reduces the skin toxicity that is seen with BRAF inhibitor monotherapy. However, this combination is associated with an increase in other toxicities, particularly drug-related pyrexia, which affects approximately 50% of patients treated with dabrafenib and trametinib (CombiDT). We provide guidance on managing adverse events likely to arise during treatment with combination BRAF and MEK inhibition with CombiDT: pyrexia, skin conditions, fatigue; and discuss management of CombiDT during surgery and radiotherapy. By improving tolerability and in particular preventing unnecessary treatment cessations or reduction in drug exposure, best outcomes can be achieved for patients undergoing CombiDT therapy.

9582 Background: While immunotherapy and MAPK-targeted therapies have improved patient outcome, the genomic heterogeneity of melanoma contributes to treatment resistance. Molecular approaches for monitoring tumor burden, treatment response and resistance has enormous potential. ctDNA may allow global representation of all disease sites, and serial ctDNA analysis can track responses and provide insights into the spatio-temporal profile of the disease. Methods: Fifty-two metastatic melanoma patients (pts) were serially monitored during sequential lines of therapy with FDG-PET scans, LDH and ctDNA. Serial tumor biopsies were collected. Five of these 52 pts consented to multiregional tumor sampling at autopsy. Allele specific digital PCR assays, customized targeted and whole exome sequencing was used to measure ctDNA levels and identify genomic alterations. Results: In BRAF and NRAS mutant patients, mutant ctDNA was detected in 72% of patients at baseline and encompassed between 0.4%-86% (median 8.2%) of total ctDNA levels. LDH and FDG-PET metabolic tumor volume correlated significantly with mutant BRAF and NRAS copies in plasma [(r=0.7818, p=0.0032) and (r=0.63, p=0.0001) respectively]. High ctDNA levels were associated with worse overall survival. ctDNA levels tracked with FDG-PET responses. Targeted sequencing of baseline ctDNA and tumor samples identified multiple mutations in clinically important genes such as MAP2K1, MAP2K2, PTEN, CDKN2A, RAC1, CTNNB1,BRAF and NRAS; high concordance was observed between ctDNA and tumor. ctDNA analysis also identified multiple mutations associated with primary and acquired resistance to MAPK-targeted therapy. Comprehensive exome sequencing of ctDNA in patients undergoing autopsy provided an accurate representation of spatial heterogeneity, when compared to multi-regional tumor sequencing. Conclusions: These findings highlight the potential clinical utility of ctDNA analysis to monitor tumor responses and disease progression in the management of metastatic melanoma patients.

BACKGROUND:Nivolumab was associated with higher rates of objective response than chemotherapy in a phase 3 study involving patients with ipilimumab-refractory metastatic melanoma. The use of nivolumab in previously untreated patients with advanced melanoma has not been tested in a phase 3 controlled study.METHODS:We randomly assigned 418 previously untreated patients who had metastatic melanoma without a BRAF mutation to receive nivolumab (at a dose of 3 mg per kilogram of body weight every 2 weeks and dacarbazine-matched placebo every 3 weeks) or dacarbazine (at a dose of 1000 mg per square meter of body-surface area every 3 weeks and nivolumab-matched placebo every 2 weeks). The primary end point was overall survival.RESULTS:At 1 year, the overall rate of survival was 72.9% (95% confidence interval [CI], 65.5 to 78.9) in the nivolumab group, as compared with 42.1% (95% CI, 33.0 to 50.9) in the dacarbazine group (hazard ratio for death, 0.42; 99.79% CI, 0.25 to 0.73; P<0.001). The median progression-free survival was 5.1 months in the nivolumab group versus 2.2 months in the dacarbazine group (hazard ratio for death or progression of disease, 0.43; 95% CI, 0.34 to 0.56; P<0.001). The objective response rate was 40.0% (95% CI, 33.3 to 47.0) in the nivolumab group versus 13.9% (95% CI, 9.5 to 19.4) in the dacarbazine group (odds ratio, 4.06; P<0.001). The survival benefit with nivolumab versus dacarbazine was observed across prespecified subgroups, including subgroups defined by status regarding the programmed death ligand 1 (PD-L1). Common adverse events associated with nivolumab included fatigue, pruritus, and nausea. Drug-related adverse events of grade 3 or 4 occurred in 11.7% of the patients treated with nivolumab and 17.6% of those treated with dacarbazine.CONCLUSIONS:Nivolumab was associated with significant improvements in overall survival and progression-free survival, as compared with dacarbazine, among previously untreated patients who had metastatic melanoma without a BRAF mutation. (Funded by Bristol-Myers Squibb; CheckMate 066 ClinicalTrials.gov number, NCT01721772.).

The hazard ratio (HR) for death was 0.42 (99.79% CI 0.25–0.73; P < 0.0001) in favor of nivolumab, with 1year OS rate 73% (95% CI, 66%–79%) for nivolumab vs 42% (95% CI, 33%–51%) for dacarbazine. Median OS was not reached for nivolumab and was 10.8 months for dacarbazine. Median progression-free survival (PFS) was 5.1 months for nivolumab and 2.2 months for dacarbazine (HR for death or progression 0.43, 95% CI 0.34–0.56; P < 0.0001). Objective response rate was 40% (84/210) vs 14% (29/208) for nivolumab and dacarbazine, respectively (P < 0.0001). Median duration of response was not reached for nivolumab and 6 months for dacarbazine. At the time of data cutoff, responses were ongoing in 86% (72/84) of nivolumab and 52% (15/29) of dacarbazine responders. PD-L1 positivity (using a 5% tumor cell surface staining cutoff) appeared to be associated with improved OS in the nivolumab arm (85% of PD-L1+ and 71% of PD-L1-/ indeterminate patients alive at the time of last followup). Both PD-L1+ and PD-L1-/indeterminate patients receiving nivolumab had improved OS vs dacarbazine (un-stratified HR 0.30, 95% CI, 0.15–0.60 in PD-L1+ patients; 0.48, 95% CI, 0.32–0.71 in PD-L1-/indeterminate patient, both in favor of the nivolumab arm). The most common nivolumab-related adverse events (AEs) were fatigue, pruritus, and nausea. Drug-related grade 3–4 AEs were reported in 12% vs 18% of patients receiving nivolumab vs dacarbazine, respectively. AEs led to discontinuation in 7% and 12% of dacarbazinevs nivolumab-treatment patients, respectively. Conclusions Compared to dacarbazine, nivolumab significantly improved OS and PFS in previously untreated patients with BRAF wild-type metastatic melanoma with an acceptable safety profile.

The endothelin system is implicated in the pathogenesis of melanoma. We evaluated the effects of bosentan - a dual endothelin receptor antagonist - in patients receiving first-line dacarbazine therapy for stage IV metastatic cutaneous melanoma in a phase 2, proof-of-concept study.