Shared and distinct biological circuits in effector, memory and exhausted CD8+ T cells revealed by temporal single-cell transcriptomics and epigenetics.

Naïve CD8+ T cells can differentiate into effector (Teff), memory (Tmem) or exhausted (Tex) T cells. These developmental pathways are associated with distinct transcriptional and epigenetic changes that endow cells with different functional capacities and therefore therapeutic potential. The molecular circuitry underlying these developmental trajectories and the extent of heterogeneity within Teff, Tmem and Tex populations remain poorly understood. Here, we used the lymphocytic choriomeningitis virus model of acute-resolving and chronic infection to address these gaps by applying longitudinal single-cell RNA-sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) analyses. These analyses uncovered new subsets, including a subpopulation of Tex cells expressing natural killer cell-associated genes that is dependent on the transcription factor Zeb2, as well as multiple distinct TCF-1+ stem/progenitor-like subsets in acute and chronic infection. These data also revealed insights into the reshaping of Tex subsets following programmed death 1 (PD-1) pathway blockade and identified a key role for the cell stress regulator, Btg1, in establishing the Tex population. Finally, these results highlighted how the same biological circuits such as cytotoxicity or stem/progenitor pathways can be used by CD8+ T cell subsets with highly divergent underlying chromatin landscapes generated during different infections.

PD-1 directed immunotherapy alters Tfh and humoral immune responses to seasonal influenza vaccine.

Anti-programmed death-1 (anti-PD-1) immunotherapy reinvigorates CD8 T cell responses in patients with cancer but PD-1 is also expressed by other immune cells, including follicular helper CD4 T cells (Tfh) which are involved in germinal centre responses. Little is known, however, about the effects of anti-PD-1 immunotherapy on noncancer immune responses in humans. To investigate this question, we examined the impact of anti-PD-1 immunotherapy on the Tfh-B cell axis responding to unrelated viral antigens. Following influenza vaccination, a subset of adults receiving anti-PD-1 had more robust circulating Tfh responses than adults not receiving immunotherapy. PD-1 pathway blockade resulted in transcriptional signatures of increased cellular proliferation in circulating Tfh and responding B cells compared with controls. These latter observations suggest an underlying change in the Tfh-B cell and germinal centre axis in a subset of immunotherapy patients. Together, these results demonstrate dynamic effects of anti-PD-1 therapy on influenza vaccine responses and highlight analytical vaccination as an approach that may reveal underlying immune predisposition to adverse events.

Human epigenetic and transcriptional T cell differentiation atlas for identifying functional T cell-specific enhancers.

The clinical benefit of T cell immunotherapies remains limited by incomplete understanding of T cell differentiation and dysfunction. We generated an epigenetic and transcriptional atlas of T cell differentiation from healthy humans that included exhausted CD8 T cells and applied this resource in three ways. First, we identified modules of gene expression and chromatin accessibility, revealing molecular coordination of differentiation after activation and between central memory and effector memory. Second, we applied this healthy molecular framework to three settings-a neoadjuvant anti-PD1 melanoma trial, a basal cell carcinoma scATAC-seq dataset, and autoimmune disease-associated SNPs-yielding insights into disease-specific biology. Third, we predicted genome-wide cis-regulatory elements and validated this approach for key effector genes using CRISPR interference, providing functional annotation and demonstrating the ability to identify targets for non-coding cellular engineering. These studies define epigenetic and transcriptional regulation of human T cells and illustrate the utility of interrogating disease in the context of a healthy T cell atlas.

Developmental Relationships of Four Exhausted CD8+ T Cell Subsets Reveals Underlying Transcriptional and Epigenetic Landscape Control Mechanisms.

CD8+ T cell exhaustion is a major barrier to current anti-cancer immunotherapies. Despite this, the developmental biology of exhausted CD8+ T cells (Tex) remains poorly defined, restraining improvement of strategies aimed at "re-invigorating" Tex cells. Here, we defined a four-cell-stage developmental framework for Tex cells. Two TCF1+ progenitor subsets were identified, one tissue restricted and quiescent and one more blood accessible, that gradually lost TCF1 as it divided and converted to a third intermediate Tex subset. This intermediate subset re-engaged some effector biology and increased upon PD-L1 blockade but ultimately converted into a fourth, terminally exhausted subset. By using transcriptional and epigenetic analyses, we identified the control mechanisms underlying subset transitions and defined a key interplay between TCF1, T-bet, and Tox in the process. These data reveal a four-stage developmental hierarchy for Tex cells and define the molecular, transcriptional, and epigenetic mechanisms that could provide opportunities to improve cancer immunotherapy.

Paradoxical Role for Wild-Type p53 in Driving Therapy Resistance in Melanoma.

Metastatic melanoma is an aggressive disease, despite recent improvements in therapy. Eradicating all melanoma cells even in drug-sensitive tumors is unsuccessful in patients because a subset of cells can transition to a slow-cycling state, rendering them resistant to most targeted therapy. It is still unclear what pathways define these subpopulations and promote this resistant phenotype. In the current study, we show that Wnt5A, a non-canonical Wnt ligand that drives a metastatic, therapy-resistant phenotype, stabilizes the half-life of p53 and uses p53 to initiate a slow-cycling state following stress (DNA damage, targeted therapy, and aging). Inhibiting p53 blocks the slow-cycling phenotype and sensitizes melanoma cells to BRAF/MEK inhibition. In vivo, this can be accomplished with a single dose of p53 inhibitor at the commencement of BRAF/MEK inhibitor therapy. These data suggest that taking the paradoxical approach of inhibiting rather than activating wild-type p53 may sensitize previously resistant metastatic melanoma cells to therapy.

TOX transcriptionally and epigenetically programs CD8+ T cell exhaustion.

Exhausted CD8+ T (Tex) cells in chronic infections and cancer have limited effector function, high co-expression of inhibitory receptors and extensive transcriptional changes compared with effector (Teff) or memory (Tmem) CD8+ T cells. Tex cells are important clinical targets of checkpoint blockade and other immunotherapies. Epigenetically, Tex cells are a distinct immune subset, with a unique chromatin landscape compared with Teff and Tmem cells. However, the mechanisms that govern the transcriptional and epigenetic development of Tex cells remain unknown. Here we identify the HMG-box transcription factor TOX as a central regulator of Tex cells in mice. TOX is largely dispensable for the formation of Teff and Tmem cells, but it is critical for exhaustion: in the absence of TOX, Tex cells do not form. TOX is induced by calcineurin and NFAT2, and operates in a feed-forward loop in which it becomes calcineurin-independent and sustained in Tex cells. Robust expression of TOX therefore results in commitment to Tex cells by translating persistent stimulation into a distinct Tex cell transcriptional and epigenetic developmental program.

Exosomal PD-L1 contributes to immunosuppression and is associated with anti-PD-1 response.

Tumour cells evade immune surveillance by upregulating the surface expression of programmed death-ligand 1 (PD-L1), which interacts with programmed death-1 (PD-1) receptor on T cells to elicit the immune checkpoint response1,2. Anti-PD-1 antibodies have shown remarkable promise in treating tumours, including metastatic melanoma2-4. However, the patient response rate is low4,5. A better understanding of PD-L1-mediated immune evasion is needed to predict patient response and improve treatment efficacy. Here we report that metastatic melanomas release extracellular vesicles, mostly in the form of exosomes, that carry PD-L1 on their surface. Stimulation with interferon-γ (IFN-γ) increases the amount of PD-L1 on these vesicles, which suppresses the function of CD8 T cells and facilitates tumour growth. In patients with metastatic melanoma, the level of circulating exosomal PD-L1 positively correlates with that of IFN-γ, and varies during the course of anti-PD-1 therapy. The magnitudes of the increase in circulating exosomal PD-L1 during early stages of treatment, as an indicator of the adaptive response of the tumour cells to T cell reinvigoration, stratifies clinical responders from non-responders. Our study unveils a mechanism by which tumour cells systemically suppress the immune system, and provides a rationale for the application of exosomal PD-L1 as a predictor for anti-PD-1 therapy.

Sentinel lymph node biopsy status improves adjuvant therapy decision-making in patients with clinical stage IIB/C melanoma: A population-based analysis.

BACKGROUND: Given the results of the recent KEYNOTE-716 trial, the performance of sentinel lymph node (SLN) biopsy for patients with clinical stage IIB/C melanoma has been questioned. OBJECTIVE: Determine the utility of SLN status in guiding the recommendations for adjuvant therapy. METHODS: Patients with clinical stage IIB/C cutaneous melanoma who underwent wide local excision and SLN biopsy between 2004 and 2011 were identified from the Surveillance, Epidemiology, and End Results database. Two prognostic models, with and without SLN status, were developed predicting risk of melanoma-specific death (MSD). The primary outcome was net benefit at treatment thresholds of 20% to 40% risk of 5-year MSD. RESULTS: For the 4391 patients included, the 5-year MSD rate was 46%. The model estimating 5-year MSD risk that included SLN status provided greater net benefit at treatment thresholds from 30% to 78% compared to the model without SLN status. The added net benefit for the SLN biopsy-containing model persisted in subgroup analysis of patients in different age groups and with various T stages. LIMITATIONS: Retrospective study. CONCLUSIONS: A prognostic model with SLN status estimating patient risk for 5-year MSD provides superior net benefit compared to a model with primary tumor staging factors alone for threshold mortality rates ≥30%.

Phase I Trial of Regorafenib, Hydroxychloroquine, and Entinostat in Metastatic Colorectal Cancer.

BACKGROUND: The antiangiogenic tyrosine kinase inhibitor regorafenib provides a survival benefit in patients with previously treated metastatic colorectal cancer (CRC). Antiangiogenic therapy causes hypoxic stress within tumor cells, which activates autophagy as a survival mechanism. The histone deacetylase inhibitor (HDAC) entinostat increases dependence on autophagy through epigenetic mechanisms. Hydroxychloroquine (HCQ) blocks autophagy by blunting lysosomal acidification. We hypothesized that HCQ and entinostat would be tolerable with regorafenib and potentiate the antitumor response. METHODS: This was a 3+3 phase I trial of HCQ and entinostat with regorafenib in patients with metastatic CRC. The primary objective was safety, and the secondary objective was clinical efficacy. RESULTS: Twenty patients received study therapy. Six evaluable patients were enrolled at each of the three planned dose levels, one patient at an intermediate dose level, and one additional patient withdrew consent after 4 days to receive treatment closer to home. One dose-limiting toxicity was noted in the study at dose level 2 (grade 3 fatigue). Seven patients discontinued therapy due to related toxicities; rapid weight loss was near universal, with a median weight loss of 4.4 kg (range 1.5-12.2 kg) in the first 2 weeks of treatment. No objective responses were observed. CONCLUSION: The combination of regorafenib, HCQ, and entinostat was poorly tolerated without evident activity in metastatic CRC. CLINICALTRIALS.GOV IDENTIFIER: NCT03215264.

Moderate Colitis Not Requiring Intravenous Steroids Is Associated with Improved Survival in Stage IV Melanoma after Anti-CTLA4 Monotherapy, But Not Combination Therapy.

BACKGROUND: For patients with melanoma, gastrointestinal immune-related adverse events are common after receipt of anti-CTLA4 therapy. These present difficult decision points regarding whether to discontinue therapy. Detailing the situations in which colitis might predict for improved survival and how this is affected by discontinuation or resumption of therapy can help guide clinical decision-making. MATERIALS AND METHODS: Patients with stage IV melanoma receiving anti-CTLA4 therapy from 2008 to 2019 were analyzed. Immune-related colitis treated with ≥50 mg prednisone or equivalent daily or secondary immunosuppression was included. Moderate colitis was defined as receipt of oral glucocorticoids only; severe colitis was defined as requiring intravenous glucocorticoids or secondary immunosuppression. The primary outcome was overall survival (OS). RESULTS: In total, 171 patients received monotherapy, and 91 received dual checkpoint therapy. In the monotherapy group, 25 patients developed colitis and a nonsignificant trend toward improved OS was observed in this group. Notably, when colitis was categorized as none, moderate or severe, OS was significantly improved for moderate colitis only. This survival difference was not present after dual checkpoint therapy. There were no differences in known prognostic variables between groups, and on multivariable analysis neither completion of all ipilimumab cycles nor resumption of immunotherapy correlated with OS, while the development of moderate colitis did significantly affect OS. CONCLUSION: This single-institution retrospective series suggests moderate colitis correlates with improved OS for patients with stage IV melanoma treated with single-agent anti-CTLA4, but not dual agent, and that this is true regardless of whether the immune-checkpoint blockade is permanently discontinued.

Compliance with sentinel lymph node biopsy guidelines for invasive melanomas treated with Mohs micrographic surgery.

BACKGROUND: Sentinel lymph node biopsy (SLNB) has not been studied for invasive melanomas treated with Mohs micrographic surgery using frozen-section MART-1 immunohistochemical stains (MMS-IHC). The primary objective of this study was to assess the accuracy and compliance with National Comprehensive Cancer Network (NCCN) guidelines for SLNB in a cohort of patients who had invasive melanoma treated with MMS-IHC. METHODS: This retrospective cohort study included all patients who had primary, invasive, cutaneous melanomas treated with MMS-IHC at a single academic center between March 2006 and April 2018. The primary outcomes were the rates of documenting discussion and performing SLNB in patients who were eligible based on NCCN guidelines. Secondary outcomes were the rate of identifying the sentinel lymph node and the percentage of positive lymph nodes. RESULTS: In total, 667 primary, invasive, cutaneous melanomas (American Joint Committee on Cancer T1a-T4b) were treated with MMS-IHC. The median patient age was 69 years (range, 25-101 years). Ninety-two percent of tumors were located on specialty sites (head and/or neck, hands and/or feet, pretibial leg). Discussion of SLNB was documented for 162 of 176 (92%) SLNB-eligible patients, including 127 of 127 (100%) who had melanomas with a Breslow depth >1 mm. SLNB was performed in 109 of 176 (62%) SLNB-eligible patients, including 102 of 158 melanomas (65%) that met NCCN criteria to discuss and offer SLNB and 7 of 18 melanomas (39%) that met criteria to discuss and consider SLNB. The sentinel lymph node was successfully identified in 98 of 109 patients (90%) and was positive in 6 of those 98 patients (6%). CONCLUSIONS: Combining SLNB and MMS-IHC allows full pathologic staging and confirmation of clear microscopic margins before reconstruction of specialty site invasive melanomas. SLNB can be performed accurately and in compliance with consensus guidelines in patients with melanoma using MMS-IHC.

Impact of Tumor-Infiltrating Lymphocytes on Overall Survival in Merkel Cell Carcinoma.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine carcinoma of the skin. As the clinical course can be variable, prognostic markers are needed to better stratify patients. Prior literature, composed of small series with limited sample size, has demonstrated that tumor-infiltrating lymphocytes (TILs) are an important prognostic marker in MCC. To validate these findings on a population level, we sought to analyze and report the prognostic value of TILs in a large national data set. MATERIALS AND METHODS: A retrospective observational cohort study was conducted of patients with nonmetastatic MCC from 2010 to 2015 using the National Cancer Database. Individual variables trending toward significance using a univariable analysis were included in a multivariable Cox proportional hazards model to assess their independent effect on overall survival (OS). TILs were subclassified into none, nonbrisk, and brisk and the survival analysis was performed. Propensity score-weighted multivariable analysis (PS MVA) was performed to adjust for additional confounding. RESULTS: A total of 2,182 patients met inclusion criteria: 611 (28.0%) were identified as having TILs present, and 1,571 (72.0%) had TILs absent in the tumor. On MVA, subdivision of TIL status into nonbrisk (hazard ratio [HR], 0.750; 95% confidence interval [CI], 0.602-0.933) and brisk (HR, 0.499; 95% CI, 0.338-0.735) was associated with incrementally improved OS compared with no TILs. The association of nonbrisk and brisk TILs with improved OS was retained on PS MVA (Nonbrisk: HR, 0.720; 95% CI, 0.550-0.944; Brisk: HR, 0.483; 95% CI, 0.286-0.814). CONCLUSION: The presence of nonbrisk and brisk TILs is associated with incrementally improved OS in patients with nonmetastatic MCC in a large national data set. This pathologic feature can aid with risk stratification, estimation of prognosis, and, importantly, decision-making with respect to treatment intensification in high-risk patients. IMPLICATIONS FOR PRACTICE: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine cutaneous malignancy with variable clinical course. Prognostic markers are needed to better risk stratify patients. We present the largest retrospective observational cohort study of patients with nonmetastatic MCC using the National Cancer Database. Our analysis demonstrates an association between increasing degrees of tumor-infiltrating lymphocytes and incrementally improved survival. These conclusions improve pathologic risk stratification, and decision-making with respect to treatment intensification. Intensification may include adjuvant radiation therapy to the primary site after wide excision despite small tumor size, to the nodal basin in sentinel lymph node-negative patients, or offering closer follow-up.

Yes, (Most) Men Know What Rape Is: A Mixed-Methods Investigation Into College Men's Definitions of Rape.

Sexual violence, including rape, is a pervasive problem on college campuses in the United States. Although men perpetrate the majority of sexual violence, men's attitudes, experiences, and perspectives are not typically included in research on rape and sexual violence. We addressed this empirical gap through our mixed-methods analysis of 365 college-aged men's definitions of the term "rape." Our analysis via consensual qualitative research revealed that men's definitions fit into nine primary domains: lack of consent, taken advantage of, sex, sexual activity, unwanted, gender/sex-specific, harm to victim, relationship, and emotional response, as well as a miscellaneous domain. Further, using chi-square tests of independence, we compared responses from men with and without histories of sexual violence perpetration. Findings showed that the definitions generated by men with a history of perpetration were less likely to include nonpenetrative sexual violence and were more likely to use gender/sex-specific language. We conclude that most young men have a generally accurate understanding of rape, though perpetrators' understandings may be somewhat narrower and more limited than those without a history of perpetration. We end with recommendations for refocusing sexual education curricula to better aid in the prevention of sexual violence perpetration. Specifically, given that (most) men know what rape is, educators should emphasize the cultural and situational factors that make rape more likely so all people can reduce the risk of sexual violence and take proactive precautions to prevent it.

Association of Age with Efficacy of Immunotherapy in Metastatic Melanoma.

Management of melanoma has been revolutionized by the use of immune checkpoint inhibitors. Immune system changes associated with aging may affect the efficacy of immune-based therapies. Using the National Cancer Database, we evaluated the impact of age on the receipt and efficacy of modern immunotherapies in patients with metastatic melanoma. We identified 11,944 patients from 2011-2015, of whom 25% received immunotherapy. Older (≥60 years), compared with younger, patients were less likely to receive immunotherapy (odds ratio, 0.69; 95% confidence interval [CI], 0.61-0.78; p < .001). Immunotherapy was associated with a survival benefit in both younger and older patients (<60 years: hazard ratio [HR], 0.64; 95% CI, 0.57-0.72; p < .001; ≥60 years: HR, 0.55; 95% CI, 0.50-0.60; p < .001). Importantly, there was a statistically significant interaction between age and survival with immunotherapy, where a greater benefit was observed for older patients (pinteraction = 0.013). Further work studying the age-related response to immunotherapy is warranted.

Neoadjuvant Versus Adjuvant Immune Checkpoint Blockade in the Treatment of Clinical Stage III Melanoma.

BACKGROUND: Immune checkpoint blockade (ICB) has transformed melanoma treatment, but optimal sequencing of ICB and surgery for clinically evident nodal metastasis remains undefined. We evaluated adjuvant-only (AT) and neoadjuvant/adjuvant (NAT) ICB with respect to survival outcomes in this patient population. METHODS: Patients who underwent lymphadenectomy (1 January 2011 to 31 July 2018) and received perioperative ICB at an academic center were identified. AT was defined as postoperative ICB, and NAT was defined as one to two cycles of ICB prior to resection with continuation of therapy following surgery. Three-year disease-free survival (DFS), locoregional recurrence-free survival (LRFS), distant disease-free survival (DDFS), and melanoma-specific survival (MSS) were estimated. RESULTS: Of 59 patients, 18 (31%) received AT and 41 (69%) received NAT. The AT and NAT groups did not differ in age (median 53 vs. 62 years, p = 0.16) or stage (IIIB 33% vs. 29%, IIIC 56% vs. 68%, IIID 11% vs. 2%, p = 0.34). Although 3-year DFS did not differ significantly by treatment sequencing (NAT vs. AT, hazard ratio [HR] 0.56, p = 0.17), NAT was associated with improved 3-year DDFS (HR 0.38, p = 0.028). Of 39 NAT patients with evaluable pathologic response, 23 (59%) and 5 (13%) had a pathologic partial response (pPR) and pathologic complete response (pCR), respectively. Patients with pPR/pCR experienced improved 3-year DFS (HR 0.16, p = 0.001), LRFS (HR 0.17, p = 0.003), and DDFS (HR 0.26, p = 0.029) compared with those with no response. Three-year MSS did not differ significantly by response (p = 0.062). CONCLUSION: NAT may be associated with improved 3-year DDFS compared with AT sequencing, and allows for early assessment of pathologic response. Further prospective evaluation of treatment sequencing is warranted.

Epacadostat plus pembrolizumab versus placebo plus pembrolizumab in patients with unresectable or metastatic melanoma (ECHO-301/KEYNOTE-252): a phase 3, randomised, double-blind study.

BACKGROUND: Immunotherapy combination treatments can improve patient outcomes. Epacadostat, an IDO1 selective inhibitor, and pembrolizumab, a PD-1 inhibitor, showed promising antitumour activity in the phase 1-2 ECHO-202/KEYNOTE-037 study in advanced melanoma. In this trial, we aimed to compare progression-free survival and overall survival in patients with unresectable stage III or IV melanoma receiving epacadostat plus pembrolizumab versus placebo plus pembrolizumab. METHODS: In this international, randomised, placebo-controlled, double-blind, parallel-group, phase 3 trial, eligible participants were aged 18 years or older, with unresectable stage III or IV melanoma previously untreated with PD-1 or PD-L1 checkpoint inhibitors, an ECOG performance status of 0 or 1, and had a known BRAFV600 mutant status or consented to BRAFV600 mutation testing during screening. Patients were stratified by PD-L1 expression and BRAFV600 mutation status and randomly assigned (1:1) through a central interactive voice and integrated web response system to receive epacadostat 100 mg orally twice daily plus pembrolizumab 200 mg intravenously every 3 weeks or placebo plus pembrolizumab for up to 2 years. We used block randomisation with a block size of four in each stratum. Primary endpoints were progression-free survival and overall survival in the intention-to-treat population. The safety analysis population included randomly assigned patients who received at least one dose of study treatment. The study was stopped after the second interim analysis; follow-up for safety is ongoing. This study is registered with ClinicalTrials.gov, number NCT02752074. FINDINGS: Between June 21, 2016, and Aug 7, 2017, 928 patients were screened and 706 patients were randomly assigned to receive epacadostat plus pembrolizumab (n=354) or placebo plus pembrolizumab (n=352). Median follow-up was 12·4 months (IQR 10·3-14·5). No significant differences were found between the treatment groups for progression-free survival (median 4·7 months, 95% CI 2·9-6·8, for epacadostat plus pembrolizumab vs 4·9 months, 2·9-6·8, for placebo plus pembrolizumab; hazard ratio [HR] 1·00, 95% CI 0·83-1·21; one-sided p=0·52) or overall survival (median not reached in either group; epacadostat plus pembrolizumab vs placebo plus pembrolizumab: HR 1·13, 0·86-1·49; one-sided p=0·81). The most common grade 3 or worse treatment-related adverse event was lipase increase, which occurred in 14 (4%) of 353 patients receiving epacadostat plus pembrolizumab and 11 (3%) of 352 patients receiving placebo plus pembrolizumab. Treatment-related serious adverse events were reported in 37 (10%) of 353 patients receiving epacadostat plus pembrolizumab and 32 (9%) of 352 patients receiving placebo plus pembrolizumab. There were no treatment-related deaths in either treatment group. INTERPRETATION: Epacadostat 100 mg twice daily plus pembrolizumab did not improve progression-free survival or overall survival compared with placebo plus pembrolizumab in patients with unresectable or metastatic melanoma. The usefulness of IDO1 inhibition as a strategy to enhance anti-PD-1 therapy activity in cancer remains uncertain. FUNDING: Incyte Corporation, in collaboration with Merck Sharp & Dohme.

Survival Outcomes of Patients with Clinical Stage III Melanoma in the Era of Novel Systemic Therapies.

BACKGROUND: Immune checkpoint and BRAF-targeted inhibitors have demonstrated significant survival benefits for advanced melanoma patients within the context of clinical trials. We sought to determine their impact on overall survival (OS) at a population level in order to better understand the current landscape for patients diagnosed with clinical stage III melanoma. METHODS: A retrospective study was performed using the National Cancer Database. Patients diagnosed with clinical stage III melanoma were categorized by diagnosis year into two cohorts preceding the advent of novel therapies (P1: 2004-2005, P2: 2008-2009) and a contemporary group (P3: 2012-2013). OS was estimated using standard time-to-event statistical methods. RESULTS: Of 3720 patients, 525 (14%) were diagnosed in P1, 1375 (37%) in P2, and 1820 (49%) in P3. Median age at diagnosis increased over time (58, 59, and 61 years in P1, P2, and P3, respectively, P = 0.004). OS increased between P2 (median 49.3 months) and P3 (median 58.2 months, Bonferroni-corrected log-rank P < 0.001) but did not differ between P1 (median 50.5 months) and P2 (Bonferroni-corrected log-rank P > 0.99). These differences persisted on multivariable analysis. OS improved for patients diagnosed in P3 compared with P1 [hazard ratio (HR) 0.76, P < 0.001] but not P2 compared with P1 (HR 0.96, P = 0.52). CONCLUSIONS: OS has significantly improved nationally for patients newly diagnosed with clinical stage III melanoma in the era of novel melanoma therapies. OS outcomes will likely continue to evolve as these agents are increasingly utilized in the adjuvant setting. These data may help to better inform affected patients with respect to prognosis.

A phase I trial of pembrolizumab with hypofractionated radiotherapy in patients with metastatic solid tumours.

BACKGROUND: We conducted a phase I trial evaluating pembrolizumab+hypofractionated radiotherapy (HFRT) for patients with metastatic cancers. METHODS: There were two strata (12 patients each): (i) NSCLC/melanoma progressing on prior anti-PD-1 therapy, (ii) other cancer types; anti-PD-1-naive. Patients received 6 cycles of pembrolizumab, starting 1 week before HFRT. Patients had ≥2 lesions; only one was irradiated (8 Gy × 3 for first half; 17 Gy × 1 for second half in each stratum) and the other(s) followed for response. RESULTS: Of the 24 patients, 20 (83%) had treatment-related adverse events (AEs) (all grade 1 or 2). There were eight grade 3 AEs, none treatment related. There were no dose-limiting toxicities or grade 4/5 AEs. Stratum 1: two patients (of 12) with progression on prior PD-1 blockade experienced prolonged responses (9.2 and 28.1 months). Stratum 2: one patient experienced a complete response and two had prolonged stable disease (7.4 and 7.0 months). Immune profiling demonstrated that anti-PD-1 therapy and radiation induced a consistent increase in the proliferation marker Ki67 in PD-1-expressing CD8 T cells. CONCLUSIONS: HFRT was well tolerated with pembrolizumab, and in some patients with metastatic NSCLC or melanoma, it reinvigorated a systemic response despite previous progression on anti-PD-1 therapy. CLINICAL TRIAL REGISTRATION: NCT02303990 ( www.clinicaltrials.gov ).