BACKGROUND An improvement in overall survival among patients with metastatic melanoma has been an elusive goal. In this phase 3 study, ipilimumab — which blocks cytotoxic T-lymphocyte–associated antigen 4 to potentiate an antitumor T-cell response — administered with or without a glycoprotein 100 (gp100) peptide vaccine was compared with gp100 alone in patients with previously treated metastatic melanoma. METHODS A total of 676 HLA-A⋆0201–positive patients with unresectable stage III or IV melanoma, whose disease had progressed while they were receiving therapy for metastatic disease, were randomly assigned, in a 3:1:1 ratio, to receive ipilimumab plus gp100 (403 patients), ipilimumab alone (137), or gp100 alone (136). Ipilimumab, at a dose of 3 mg per kilogram of body weight, was administered with or without gp100 every 3 weeks for up to four treatments (induction). Eligible patients could receive reinduction therapy. The primary end point was overall survival. RESULTS The median overall survival was 10.0 months among patients receiving ipilimumab plus gp100, as compared with 6.4 months among patients receiving gp100 alone (hazard ratio for death, 0.68; P<0.001). The median overall survival with ipilimumab alone was 10.1 months (hazard ratio for death in the comparison with gp100 alone, 0.66; P = 0.003). No difference in overall survival was detected between the ipilimumab groups (hazard ratio with ipilimumab plus gp100, 1.04; P = 0.76). Grade 3 or 4 immune-related adverse events occurred in 10 to 15% of patients treated with ipilimumab and in 3% treated with gp100 alone. There were 14 deaths related to the study drugs (2.1%), and 7 were associated with immune-related adverse events. CONCLUSIONS Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overall survival in patients with previously treated metastatic melanoma. Adverse events can be severe, long-lasting, or both, but most are reversible with appropriate treatment. (Funded by Medarex and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00094653.)

Immune checkpoint inhibitors, which unleash a patient’s own T cells to kill tumors, are revolutionizing cancer treatment. To unravel the genomic determinants of response to this therapy, we used whole-exome sequencing of non–small cell lung cancers treated with pembrolizumab, an antibody targeting programmed cell death-1 (PD-1). In two independent cohorts, higher nonsynonymous mutation burden in tumors was associated with improved objective response, durable clinical benefit, and progression-free survival. Efficacy also correlated with the molecular smoking signature, higher neoantigen burden, and DNA repair pathway mutations; each factor was also associated with mutation burden. In one responder, neoantigen-specific CD8+ T cell responses paralleled tumor regression, suggesting that anti–PD-1 therapy enhances neoantigen-specific T cell reactivity. Our results suggest that the genomic landscape of lung cancers shapes response to anti–PD-1 therapy.

Background The results of phase 1 and phase 2 studies suggest that nivolumab (a PD-1 checkpoint inhibitor) and ipilimumab (a CTLA-4 checkpoint inhibitor) have complementary activity in metastatic melanoma. In this randomized, double-blind, phase 3 study, nivolumab alone or nivolumab combined with ipilimumab versus ipilimumab alone were evaluated in patients with metastatic melanoma. Methods We randomly assigned 945 previously untreated patients with unresectable stage III or IV melanoma, in 1:1:1 ratio, to nivolumab alone (3 mg per kilogram of body weight every 2 weeks), or to nivolumab (at a dose of 1 mg per kilogram) plus ipilimumab (at a dose of 3 mg per kilogram) every 3 weeks for 4 doses followed by nivolumab (3 mg per kilogram every 2 weeks), or to ipilimumab alone (3 mg per kilogram every 3 weeks for 4 doses). Progression-free and overall survival were co-primary end points. Patients continue to be followed for overall survival. Results Median progression-free survival was 11.5 months (95% confidence interval [CI], 8.9 to 16.7) for nivolumab plus ipilimumab as compared with 2.9 months (95% CI, 2.8 to 3.4) for ipilimumab alone (hazard ratio, 0.42; 95% CI, 0.31 to 0.57; P<0.00001), and was 6.9 months (95% CI, 4.3 to 9.5) for nivolumab alone (hazard ratio in the comparison with ipilimumab alone, 0.57; 95% CI, 0.43 to 0.76; P<0.00001). In PD-L1-positive patients, median progression-free survival was 14.0 months in both the nivolumab plus ipilimumab and nivolumab alone groups, but in PD-L1-negative patients, progression-free survival was longer with the combination as compared with nivolumab alone (11.2 months [95% CI, 8.0 to not reached] versus 5.3 months [95% CI, 2.8 to 7.1]). Grade 3–4 drug-related adverse events occurred in 16.3%, 55.0%, and 27.3% of patients in the nivolumab, nivolumab plus ipilimumab, and ipilimumab alone groups, with 1, 0, and 1 drug-related deaths, respectively. Conclusions Nivolumab alone or combined with ipilimumab significantly improved progression-free survival, as compared with ipilimumab, among previously untreated patients with metastatic melanoma. Results with the combination versus either agent alone suggest complementary activity between PD-1 and CTLA-4 blockade, particularly for patients with PD-L1-negative tumors. (Funded by Bristol-Myers Squibb; CheckMate 067, ClinicalTrials.gov number, NCT01844505.)

The release of negative regulators of immune activation (immune checkpoints) that limit antitumor responses has resulted in unprecedented rates of long-lasting tumor responses in patients with a variety of cancers. This can be achieved by antibodies blocking the cytotoxic T lymphocyte-associated protein 4 (CTLA-4) or the programmed cell death 1 (PD-1) pathway, either alone or in combination. The main premise for inducing an immune response is the preexistence of antitumor T cells that were limited by specific immune checkpoints. Most patients who have tumor responses maintain long-lasting disease control, yet one-third of patients relapse. Mechanisms of acquired resistance are currently poorly understood, but evidence points to alterations that converge on the antigen presentation and interferon-γ signaling pathways. New-generation combinatorial therapies may overcome resistance mechanisms to immune checkpoint therapy.

Tumor-derived exosomes are emerging mediators of tumorigenesis with tissue-specific addresses and messages. We explored the function of melanoma-derived exosomes in the formation of primary tumor and metastases in mouse and human subjects. Exosomes from highly metastatic melanoma increased the metastatic behavior of primary tumors by permanently “educating” bone marrow (BM) progenitors via the MET receptor. Melanoma-derived exosomes also induced vascular leakiness at pre-metastatic sites, and reprogrammed BM progenitors towards a c-Kit+Tie2+Met+ pro-vasculogenic phenotype. Reducing Met expression in exosomes diminished the pro-metastatic behavior of BM cells. Importantly, MET expression was elevated in circulating CD45−C-KITlow/+TIE2+ BM progenitors from metastatic melanoma subjects. RAB1a, RAB5b, RAB7, and RAB27a were highly expressed in melanoma cells and Rab27a RNA interference decreased exosome production, preventing BM education, tumor growth and metastasis. Finally, we identified an exosome-specific “melanoma signature” with prognostic and therapeutic potential, comprised of TYRP2, VLA-4, HSP70, an HSP90 isoform and the MET oncoprotein.

BACKGROUND Immune checkpoint inhibitors are effective cancer treatments, but molecular determinants of clinical benefit are unknown. Ipilimumab and tremelimumab are antibodies against cytotoxic T-lymphocyte antigen 4 (CTLA-4). Anti–CTLA-4 treatment prolongs overall survival in patients with melanoma. CTLA-4 blockade activates T cells and enables them to destroy tumor cells. METHODS We obtained tumor tissue from patients with melanoma who were treated with ipilimumab or tremelimumab. Whole-exome sequencing was performed on tumors and matched blood samples. Somatic mutations and candidate neoantigens generated from these mutations were characterized. Neoantigen peptides were tested for the ability to activate lymphocytes from ipilimumab-treated patients. RESULTS Malignant melanoma exomes from 64 patients treated with CTLA-4 blockade were characterized with the use of massively parallel sequencing. A discovery set consisted of 11 patients who derived a long-term clinical benefit and 14 patients who derived a minimal benefit or no benefit. Mutational load was associated with the degree of clinical benefit (P = 0.01) but alone was not sufficient to predict benefit. Using genomewide somatic neoepitope analysis and patient-specific HLA typing, we identified candidate tumor neoantigens for each patient. We elucidated a neo-antigen landscape that is specifically present in tumors with a strong response to CTLA-4 blockade. We validated this signature in a second set of 39 patients with melanoma who were treated with anti–CTLA-4 antibodies. Predicted neoantigens activated T cells from the patients treated with ipilimumab. CONCLUSIONS These findings define a genetic basis for benefit from CTLA-4 blockade in melanoma and provide a rationale for examining exomes of patients for whom anti–CTLA-4 agents are being considered. (Funded by the Frederick Adler Fund and others.)

Purpose To increase awareness, outline strategies, and offer guidance on the recommended management of immune-related adverse events in patients treated with immune checkpoint inhibitor (ICPi) therapy. Methods A multidisciplinary, multi-organizational panel of experts in medical oncology, dermatology, gastroenterology, rheumatology, pulmonology, endocrinology, urology, neurology, hematology, emergency medicine, nursing, trialist, and advocacy was convened to develop the clinical practice guideline. Guideline development involved a systematic review of the literature and an informal consensus process. The systematic review focused on guidelines, systematic reviews and meta-analyses, randomized controlled trials, and case series published from 2000 through 2017. Results The systematic review identified 204 eligible publications. Much of the evidence consisted of systematic reviews of observational data, consensus guidelines, case series, and case reports. Due to the paucity of high-quality evidence on management of immune-related adverse events, recommendations are based on expert consensus. Recommendations Recommendations for specific organ system-based toxicity diagnosis and management are presented. While management varies according to organ system affected, in general, ICPi therapy should be continued with close monitoring for grade 1 toxicities, with the exception of some neurologic, hematologic, and cardiac toxicities. ICPi therapy may be suspended for most grade 2 toxicities, with consideration of resuming when symptoms revert to grade 1 or less. Corticosteroids may be administered. Grade 3 toxicities generally warrant suspension of ICPis and the initiation of high-dose corticosteroids (prednisone 1 to 2 mg/kg/d or methylprednisolone 1 to 2 mg/kg/d). Corticosteroids should be tapered over the course of at least 4 to 6 weeks. Some refractory cases may require infliximab or other immunosuppressive therapy. In general, permanent discontinuation of ICPis is recommended with grade 4 toxicities, with the exception of endocrinopathies that have been controlled by hormone replacement. Additional information is available at www.asco.org/supportive-care-guidelines and www.asco.org/guidelineswiki .

Ipilimumab (at a dose of 10 mg per kilogram) in combination with dacarbazine, as compared with dacarbazine plus placebo, improved overall survival in patients with previously untreated metastatic melanoma. The types of adverse events were consistent with those seen in prior studies of ipilimumab; however, the rates of elevated liver-function values were higher and the rates of gastrointestinal events were lower than expected on the basis of prior studies. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00324155.).