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With the successful development of immune checkpoint blockade, there remains the continued need to improve efficacy and decrease toxicities. The addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) to ipilimumab has previously demonstrated both an improvement in efficacy and decrease in the incidence of high-grade adverse events. ICOS+CD4+ or ICOS+CD8+ peripheral blood T cells are significantly greater in the patients treated with ipilimumab plus GM-CSF than in the patients treated with ipilimumab alone. To better understand the effects of GM-CSF on inducible T-cell costimulator (ICOS) and clinical outcomes, the relative roles of identified soluble ICOS and membrane-bound ICOS were evaluated. The ICOS splice variant was secreted and found to have immunologic suppressive effects. Changes in soluble ICOS splice variant levels in treated patients correlated with clinical outcomes. GM-CSF enhanced membrane-bound ICOS in an IL12-dependent manner but did not increase soluble ICOS levels. Whereas soluble ICOS plays a role in immune suppression, GM-CSF efficacy involves increasing membrane-bound ICOS and induction of dendritic cell development. Thus, soluble ICOS splice variants may be used as a biomarker for GM-CSF and immune checkpoint blockade-based therapies.

Introduction Delayed-type drug hypersensitivity reactions (dtDHRs) are a major cause of morbidity and mortality, with considerable cost to healthcare systems (1-5). Skin is the most commonly affected organ. Severity ranges [...], Delayed-type drug hypersensitivity reactions are major causes of morbidity and mortality. The origin, phenotype, and function of pathogenic T cells across the spectrum of severity require investigation. We leveraged recent technical advancements to study skin-resident memory T cells (TRMs) versus recruited T cell subsets in the pathogenesis of severe systemic forms of disease, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS), and skin-limited disease, morbilliform drug eruption (MDE). Microscopy, bulk transcriptional profiling, and single-cell RNA-sequencing (scRNA-Seq) plus cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) plus T cell receptor sequencing (TCR-Seq) supported clonal expansion and recruitment of cytotoxic [CD8.sup.+] T cells from circulation into skin along with expanded and nonexpanded cytotoxic [CD8.sup.+] skin TRM in SJS/TEN. Comparatively, MDE displayed a cytotoxic T cell profile in skin without appreciable expansion and recruitment of cytotoxic [CD8.sup.+] T cells from circulation, implicating TRMs as potential protagonists in skin-limited disease. Mechanistic interrogation in patients unable to recruit T cells from circulation into skin and in a parallel mouse model supported that skin TRMs were sufficient to mediate MDE. Concomitantly, SJS/TEN displayed a reduced Treg signature compared with MDE. DRESS demonstrated recruitment of cytotoxic [CD8.sup.+] T cells into skin as in SJS/TEN, yet a pro-Treg signature as in MDE. These findings have important implications for fundamental skin immunology and clinical care.

IntroductionMerkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine malignancy of the skin with a predilection for metastases. This study investigates the clinical outcomes in patients presenting with de novo Stage IV MCC according to the metastatic site(s) at presentation.Materials and methodsPatients who presented with one or more sites of distant metastatic MCC at initial diagnosis between 2009 and 2023 were identified. The presence or absence of one or more metastases in each organ was categorized for each patient at the time of diagnosis. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Competing risk analysis was used to estimate the cumulative occurrence risk of MCC-specific death. Fisher’s exact test was used for response rate analysis. Results were considered statically significant if p < 0.05.ResultsThirty-four patients presented with de novo distant metastatic MCC. There was no association between the number of metastatic sites at diagnosis and OS (p= 0.58), PFS (p=0.79), or response rates (p=0.53). However, the presence of bone metastases was associated with significantly shorter OS (8.2 versus 25.2 months, HR: 2.4, 95% CI 1.01-5.7, p= 0.04). MCC-specific death in patients with lymph node metastases was significantly lower than in patients without (HR: 0.28, 95% CI: 0.09-0.87, p= 0.013). The presence of bone metastases tended to associate with an increased risk of MCC-specific death, although not statistically significant. The location of metastases was not associated with the response rate to first-line treatment. There was no significant association between site of metastases and PFS.ConclusionIn this cohort of patients with de novo metastatic MCC, the presence of bone metastases, but not the number of organs involved, was associated with significantly worse OS. The presence of lymph node metastases was associated with lower MCC-specific death. Further research is warranted in larger cohorts to investigate the impact of the location of metastases on clinical outcomes.

Background The combination of ipilimumab and nivolumab is a highly effective treatment for metastatic cutaneous melanoma. However, immune-related adverse events (irAEs) are common, often necessitating treatment interruption and the use of immunosuppressive agents. There is no data on the impact of resuming nivolumab on survival following recovery from the irAE and completion of immunosuppressive treatment.Patients and methods In this retrospective analysis, we examined a cohort of patients treated with ipilimumab/nivolumab who developed irAEs requiring treatment interruption and immunosuppressive therapy. The differences in physician practice patterns at our institution allowed us to examine the survival effect of restarting single-agent nivolumab. A multivariate analysis of clinical factors associated with improved survival was performed.Results We identified 165 patients who were treated with ipilimumab/nivolumab and developed irAEs requiring treatment interruption and immunosuppressive therapy. Patients with the best overall response of progressive disease were excluded. Of the remaining 122 patients, 46 resumed single-agent nivolumab. When stratified by age and adjusted for sex, M-stage, lactate dehydrogenase (LDH), therapy duration, and irAE type, the effect of resumption of nivolumab on survival was highly significant (p=0.02). Patients who resumed nivolumab had a 68% reduction in the hazard of death compared with patients who had not yet or never resumed nivolumab (HR: 0.32, 95% CI: 0.12 to 0.84). Of the patients who resumed nivolumab, 12 (26%) patients had subsequent irAEs, with five patients having grade 3 irAEs. No grade 4 or 5 irAEs were noted.Conclusions Resuming single-agent nivolumab following a treatment interruption for ipilimumab/nivolumab-associated irAE and completion of immunosuppressive therapy increased overall survival compared with discontinuing nivolumab permanently in patients with metastatic melanoma. Toxicity observed post-resumption of single-agent nivolumab was manageable with no severe irAEs observed.

BackgroundPatients with non-small-cell lung cancer (NSCLC) that is resistant to PD-1 and PD-L1 (PD[L]-1)-targeted therapy have poor outcomes. Studies suggest that radiotherapy could enhance antitumour immunity. Therefore, we investigated the potential benefit of PD-L1 (durvalumab) and CTLA-4 (tremelimumab) inhibition alone or combined with radiotherapy.MethodsThis open-label, multicentre, randomised, phase 2 trial was done by the National Cancer Institute Experimental Therapeutics Clinical Trials Network at 18 US sites. Patients aged 18 years or older with metastatic NSCLC, an Eastern Cooperative Oncology Group performance status of 0 or 1, and progression during previous PD(L)-1 therapy were eligible. They were randomly assigned (1:1:1) in a web-based system by the study statistician using a permuted block scheme (block sizes of three or six) without stratification to receive either durvalumab (1500 mg intravenously every 4 weeks for a maximum of 13 cycles) plus tremelimumab (75 mg intravenously every 4 weeks for a maximum of four cycles) alone or with low-dose (0·5 Gy delivered twice per day, repeated for 2 days during each of the first four cycles of therapy) or hypofractionated radiotherapy (24 Gy total delivered over three 8-Gy fractions during the first cycle only), 1 week after initial durvalumab-tremelimumab administration. Study treatment was continued until 1 year or until progression. The primary endpoint was overall response rate (best locally assessed confirmed response of a partial or complete response) and, along with safety, was analysed in patients who received at least one dose of study therapy. The trial is registered with ClinicalTrials.gov, NCT02888743, and is now complete.FindingsBetween Aug 24, 2017, and March 29, 2019, 90 patients were enrolled and randomly assigned, of whom 78 (26 per group) were treated. This trial was stopped due to futility assessed in an interim analysis. At a median follow-up of 12·4 months (IQR 7·8-15·1), there were no differences in overall response rates between the durvalumab-tremelimumab alone group (three [11·5%, 90% CI 1·2-21·8] of 26 patients) and the low-dose radiotherapy group (two [7·7%, 0·0-16·3] of 26 patients; p=0·64) or the hypofractionated radiotherapy group (three [11·5%, 1·2-21·8] of 26 patients; p=0·99). The most common grade 3-4 adverse events were dyspnoea (two [8%] in the durvalumab-tremelimumab alone group; three [12%] in the low-dose radiotherapy group; and three [12%] in the hypofractionated radiotherapy group) and hyponatraemia (one [4%] in the durvalumab-tremelimumab alone group vs two [8%] in the low-dose radiotherapy group vs three [12%] in the hypofractionated radiotherapy group). Treatment-related serious adverse events occurred in one (4%) patient in the durvalumab-tremelimumab alone group (maculopapular rash), five (19%) patients in the low-dose radiotherapy group (abdominal pain, diarrhoea, dyspnoea, hypokalemia, and respiratory failure), and four (15%) patients in the hypofractionated group (adrenal insufficiency, colitis, diarrhoea, and hyponatremia). In the low-dose radiotherapy group, there was one death from respiratory failure potentially related to study therapy.InterpretationRadiotherapy did not increase responses to combined PD-L1 plus CTLA-4 inhibition in patients with NSCLC resistant to PD(L)-1 therapy. However, PD-L1 plus CTLA-4 therapy could be a treatment option for some patients. Future studies should refine predictive biomarkers in this setting.FundingThe US National Institutes of Health and the Dana-Farber Cancer Institute.

BackgroundIn the era of immune checkpoint blockade, the role of cancer vaccines in immune priming has provided additional potential for therapeutic improvements. Prior studies have demonstrated delayed type hypersensitivity and anti-tumor immunity with vaccines engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF). The safety, efficacy and anti-tumor immunity of GM-CSF secreting vaccine in patients with previously treated stage III or IV melanoma needs further investigation.MethodsIn this phase II trial, excised lymph node metastases were processed to single cells, transduced with an adenoviral vector encoding GM-CSF, irradiated, and cryopreserved. Individual vaccines were composed of 1x106, 4x106, or 1x107 tumor cells, and were injected intradermally and subcutaneously at weekly and biweekly intervals. The primary endpoints were feasibility of producing vaccine in stage III patients and determining the proportion of patients alive at two years in stage IV patients.ResultsGM-CSF vaccine was successfully developed and administered in all 61 patients. Toxicities were restricted to grade 1-2 local skin reactions. The median OS for stage III patients (n = 20) was 71.1 (95% CI, 43.7 to NR) months and 14.9 (95%CI, 12.1 to 39.7) months for stage IV patients. The median PFS in stage III patients was 50.7 (95%CI, 36.3 to NR) months and 4.1 (95% CI, 3.0-6.3) months in stage IV patients. In the overall population, the disease control rate was 39.3% (95%CI, 27.1 to 52.7%). In stage III patients, higher pre-treatment plasma cytokine levels of MMP-1, TRAIL, CXCL-11, CXCL-13 were associated with improved PFS (p

PurposeProspective human data are lacking regarding safety, efficacy, and immunologic impacts of different radiation doses administered with combined PD-L1/CTLA-4 blockade.Patients and methodsWe performed a multicenter phase II study randomly assigning patients with metastatic microsatellite stable colorectal cancer to repeated low-dose fractionated radiation (LDFRT) or hypofractionated radiation (HFRT) with PD-L1/CTLA-4 inhibition. The primary endpoint was response outside the radiation field. Correlative samples were analyzed using multiplex immunofluorescence (IF), IHC, RNA/T-cell receptor (TCR) sequencing, cytometry by time-of-flight (CyTOF), and Olink.ResultsEighteen patients were evaluable for response. Median lines of prior therapy were four (range, 1-7). Sixteen patients demonstrated toxicity potentially related to treatment (84%), and 8 patients had grade 3-4 toxicity (42%). Best response was stable disease in 1 patient with out-of-field tumor shrinkage. Median overall survival was 3.8 months (90% confidence interval, 2.3-5.7 months). Correlative IF and RNA sequencing (RNA-seq) revealed increased infiltration of CD8+ and CD8+/PD-1+/Ki-67+ T cells in the radiation field after HFRT. LDFRT increased foci of micronuclei/primary nuclear rupture in two subjects. CyTOF and RNA-seq demonstrated significant declines in multiple circulating immune populations, particularly in patients receiving HFRT. TCR sequencing revealed treatment-associated changes in T-cell repertoire in the tumor and peripheral blood.ConclusionsWe demonstrate the feasibility and safety of adding LDFRT and HFRT to PD-L1/CTLA-4 blockade. Although the best response of stable disease does not support the use of concurrent PD-L1/CTLA-4 inhibition with HFRT or LDFRT in this population, biomarkers provide support that both LDFRT and HFRT impact the local immune microenvironment and systemic immunogenicity that can help guide future studies.

Abstract Atezolizumab with chemotherapy has shown improved progression-free and overall survival in patients with metastatic PD-L1 positive triple negative breast cancer (TNBC). Atezolizumab with anthracycline- and taxane-based neoadjuvant chemotherapy has also shown increased pathological complete response (pCR) rates in early TNBC. This trial evaluated neoadjuvant carboplatin and paclitaxel with or without atezolizumab in patients with clinical stages II-III TNBC. The co-primary objectives were to evaluate if chemotherapy and atezolizumab increase pCR rate and tumor infiltrating lymphocyte (TIL) percentage compared to chemotherapy alone in the mITT population. Sixty-seven patients (ages 25–78 years; median, 52 years) were randomly assigned – 22 patients to Arm A, and 45 to Arm B. Median follow up was 6.6 months. In the modified intent to treat population (all patients evaluable for the primary endpoints who received at least one dose of combination therapy), the pCR rate was 18.8% (95% CI 4.0–45.6%) in Arm A, and 55.6% (95% CI 40.0–70.4%) in Arm B (estimated treatment difference: 36.8%, 95% CI 8.5–56.6%; p = 0.018). Grade 3 or higher treatment-related adverse events occurred in 62.5% of patients in Arm A, and 57.8% of patients in Arm B. One patient in Arm B died from recurrent disease during the follow-up period. TIL percentage increased slightly from baseline to cycle 1 in both Arm A (mean ± SD: 0.6% ± 21.0%) and Arm B (5.7% ± 15.8%) (p = 0.36). Patients with pCR had higher median TIL percentages (24.8%) than those with non-pCR (14.2%) (p = 0.02). Although subgroup analyses were limited by the small sample size, PD-L1-positive patients treated with chemotherapy and atezolizumab had a pCR rate of 75% (12/16). The addition of atezolizumab to neoadjuvant carboplatin and paclitaxel resulted in a statistically significant and clinically relevant increased pCR rate in patients with clinical stages II and III TNBC. (Funded by National Cancer Institute).

Abstract High-grade meningiomas are associated with neuro-cognitive morbidity and have limited treatments. High-grade meningiomas harbor an immunosuppressive tumor microenvironment (TME) and programmed death-ligand 1 (PD-L1) expression may contribute to their aggressive phenotype. Here, we present the results of a single-arm, open-label phase 2 trial (NCT03279692) evaluating the efficacy of pembrolizumab, a PD-1 inhibitor, in a cohort of 25 evaluable patients with recurrent and progressive grade 2 and 3 meningiomas. The primary endpoint is the proportion of patients alive and progression-free at 6 months (PFS-6). Secondary endpoints include progression-free and overall survival, best intracranial response, and toxicity. Our study has met its primary endpoint and achieved a PFS-6 rate of 0.48 (90% exact CI: 0.31–0.66) and a median PFS of 7.6 months (90% CI: 3.4–12.9 months). Twenty percent of patients have experienced one (or more) grade-3 or higher treatment-related adverse events. These results suggest that pembrolizumab exerts promising efficacy on a subset of these tumors. Further studies are needed to identify the biological facets within the meningioma TME that may drive response to immune-based therapies.

Background Merkel cell carcinoma (MCC) is an aggressive neuroendocrine (NE) skin cancer caused by severe UV-induced mutations or expression of Merkel cell polyomavirus (MCPyV) large and small T antigens (LT and ST). Despite deep genetic differences between MCPyV-positive and -negative subtypes, current clinical diagnostic markers are indistinguishable, and the expression profile of MCC tumors is, to our knowledge, unexplored.Methods Here, we leveraged bulk and single-cell RNA-Seq of patient-derived tumor biopsies and cell lines to explore the underlying transcriptional environment of MCC.Results Strikingly, MCC samples could be separated into transcriptional subtypes that were independent of MCPyV status. Instead, we observed an inverse correlation between a NE gene signature and the Hippo pathway transcription factors Yes1-associated transcriptional regulator (YAP1) and WW domain–containing transcriptional regulator 1 (WWTR1). This inverse correlation was broadly present at the transcript and protein levels in the tumor biopsies as well as in established and patient-derived cell lines. Mechanistically, expression of YAP1 or WWTR1 in a MCPyV-positive MCC cell line induced cell-cycle arrest at least in part through TEA domain–dependent (TEAD-dependent) transcriptional repression of MCPyV LT.Conclusion These findings identify what we believe to be a previously unrecognized heterogeneity in NE gene expression within MCC and support a model of YAP1/WWTR1 silencing as essential for the development of MCPyV-positive MCC.Funding US Public Health Service grants R35CA232128, P01CA203655, and P30CA06516.

Leptomeningeal metastases from solid tumors are a rare complication with a very poor prognosis. Here the authors report the efficacy and safety of combined ipilimumab and nivolumab in patients with leptomeningeal carcinomatosis.

A randomized phase 2 clinical trial has recently shown no benefit of the combination eribulin and pembrolizumab over pembrolizumab alone in HR + metastatic breast cancer patients (NCT03051659). Here, the authors are reporting the final OS data and biomarker analyses on a subset of samples to analyze molecular correlates

Introduction: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine malignancy of the skin with a predilection for metastases. This study investigates the clinical outcomes in patients presenting with de novo Stage IV MCC according to the metastatic site(s) at presentation. Materials and methods: Patients who presented with one or more sites of distant metastatic MCC at initial diagnosis between 2009 and 2023 were identified. The presence or absence of one or more metastases in each organ was categorized for each patient at the time of diagnosis. Overall survival (OS) and progressionfree survival (PFS) were estimated using the Kaplan-Meier method. Competing risk analysis was used to estimate the cumulative occurrence risk of MCCspecific death. Fisher's exact test was used for response rate analysis. Results were considered statically significant if p < 0.05. Results: Thirty-four patients presented with de novo distant metastatic MCC. There was no association between the number of metastatic sites at diagnosis and OS (p= 0.58), PFS (p=0.79), or response rates (p=0.53). However, the presence of bone metastases was associated with significantly shorter OS (8.2 versus 25.2 months, HR: 2.4, 95% CI 1.01-5.7, p= 0.04). MCC-specific death in patients with lymph node metastases was significantly lower than in patients without (HR: 0.28, 95% CI: 0.09-0.87, p= 0.013). The presence of bone metastases tended to associate with an increased risk of MCC-specific death, although not statistically significant. The location of metastases was not associated with the response rate to first-line treatment. There was no significant association between site of metastases and PFS. Conclusion: In this cohort of patients with de novo metastatic MCC, the presence of bone metastases, but not the number of organs involved, was associated with significantly worse OS. The presence of lymph node metastases was associated with lower MCC-specific death. Further research is warranted in larger cohorts to investigate the impact of the location of metastases on clinical outcomes. [ABSTRACT FROM AUTHOR]

Background: Hot flashes are a common side effect of endocrine therapy (ET) that contribute to poor quality of life and decreased treatment adherence. Methods: Patients with breast cancer wo were receiving ET and experiencing hot flashes were enrolled through three parallel, randomized trials conducted in the United States, China, and South Korea. Participants were randomized to either immediate acupuncture (IA) or delayed acupuncture control (DAC). IA participants received 20 acupuncture sessions over 10 weeks, whereas DAC participants received usual care, then crossed over to acupuncture with a reduced intensity. The primary end point was a change in score on the endocrine symptom subscale of the Functional Assessment of Cancer Therapy (FACT)‐Endocrine Symptoms between baseline and week 10. Secondary end points included the hot flash score and the FACT‐Breast score. A planned pooled analysis of individual patient data was performed using longitudinal mixed models. Results: In total, 158 women with stage 0–III breast cancer were randomized (United States, n = 78; China, n = 40; South Korea, n = 40). At week 10, IA participants reported statistically significant improvements in the endocrine symptom subscale score (mean change ± standard error: 5.1 ± 0.9 vs. 0.2 ± 1.0; p =.0003), the hot flash score (−5.3 ± 0.9 vs. −1.4 ± 0.9; p <.003), and the FACT‐Breast total score (8.0 ± 1.6 vs. −0.01 ± 1.6; p =.0005) compared with DAC participants. The effect of the acupuncture intervention differed by site (p =.005). Conclusions: Acupuncture led to statistically and clinically meaningful improvements in hot flashes, endocrine symptoms, and breast cancer‐specific quality of life in women undergoing ET for breast cancer in the United States, China, and South Korea. In a pooled analysis of three parallel trials, acupuncture significantly reduced hot flashes and other endocrine symptoms in women with stage 0–III breast cancer undergoing endocrine therapy in the United States, China, and South Korea. In the women studied, acupuncture led to statistically and clinically meaningful improvements in hot flashes, endocrine symptoms, and breast cancer‐specific quality of life. [ABSTRACT FROM AUTHOR]

Introduction: To evaluate the impact of Sars-Cov-2 infection on mortality and immune checkpoint inhibitor (ICI) toxicity in patients with cancer receiving ICIs compared to those not receiving ICIs. Methods: We conducted a retrospective matched cohort study of 25 patients receiving ICIs within 1 year of coronavirus disease 2019 (COVID-19) diagnosis between March 20, 2020, and June 3, 2020, at the Dana-Farber Cancer Institute/Mass General Brigham. Cases were matched 1:1 with controls based on age, sex, and anticancer therapy within the prior 6 months. Results: Seven of 25 (28%) patients receiving ICIs died from COVID-19 as compared with nine of 25 (36%) controls. Through multivariable analysis adjusting for age, sex, and anticancer therapy, ICI use was not associated with increased risk for COVID-19 death (OR [odds ratio] 0.36, 95% CI 0.07–1.87). Determinants of mortality included age (OR 1.14, 95% CI 1.03–1.27) and chronic obstructive pulmonary disease (OR 12.26, 95% CI 1.76–85.14). Statin use was protective against mortality (OR 0.08, 95% CI 0.01–0.63). Two patients experienced persistent immune-related adverse events (irAEs) (hypophysitis); one had new-onset irAE (hypothyroidism) during their COVID-19 course. Patients with ICIs had significantly higher platelet (p = 0.017) and D-dimer (p = 0.037) levels. Elevated troponin levels (p = 0.01) were associated with COVID-19 death in patients using ICI. Conclusion: There is insufficient evidence to conclude COVID-19–related outcomes are associated with ICIs, and we did not observe an increased risk of COVID-19–related death associated with ICIs. The potential protective effect of statin therapy and role of laboratory biomarkers warrant further investigation.

Abstract Mucosal melanoma is a rare form of melanoma which arises from melanocytes in the mucosal membranes and can be effectively treated with immune checkpoint blockade (ICB). However, response rates in mucosal melanoma are lower than those observed for cutaneous melanomas. Targeted sequencing of up to 447 genes (OncoPanel) was performed on tumors from all mucosal melanoma patients seen at the Dana‐Farber Cancer Institute from 2011 until March 2019. We identified a total of 46 patients who received ICB with both tumor‐genotype and ICB response data available. Within this cohort of patients, 16 (35%) had durable clinical benefit (DCB) to their first line of ICB. The average mutational burden/megabase was 6.23 and did not correlate with tumor response to ICB. Patients with KIT aberrations had a higher DCB rate compared with patients with wildtype KIT (71 vs. 28%), but this was not found to be statistically significant. For comparison, we analyzed tumor genotypes from an additional 50 mucosal melanoma tumors and 189 cutaneous melanoma tumors. The most frequent mutations in mucosal melanoma were in SF3B1 (27%), KIT (18%), and NF1 (17%), a pattern that is distinct from cutaneous melanomas. In addition, there were genetic differences observed based upon the site of origin of the mucosal melanoma. Our findings explore clinical features of response in patients with mucosal melanoma treated with ICB and demonstrate a low mutational burden that does not correlate with response. In addition, the lack of significant association between the genetic aberrations tested and response to ICB indicates the need for further exploration in this patient population.

Abstract Background Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine carcinoma of the skin caused by either the integration of Merkel cell polyomavirus (MCPyV) and expression of viral T antigens or by ultraviolet-induced damage to the tumor genome from excessive sunlight exposure. An increasing number of deep sequencing studies of MCC have identified significant differences between the number and types of point mutations, copy number alterations, and structural variants between virus-positive and virus-negative tumors. However, it has been challenging to reliably distinguish between virus positive and UV damaged MCC. Methods In this study, we assembled a cohort of 71 MCC patients and performed deep sequencing with OncoPanel, a clinically implemented, next-generation sequencing assay targeting over 400 cancer-associated genes. To improve the accuracy and sensitivity for virus detection compared to traditional PCR and IHC methods, we developed a hybrid capture baitset against the entire MCPyV genome and software to detect integration sites and structure. Results Sequencing from this approach revealed distinct integration junctions in the tumor genome and generated assemblies that strongly support a model of microhomology-initiated hybrid, virus-host, circular DNA intermediate that promotes focal amplification of host and viral DNA. Using the clear delineation between virus-positive and virus-negative tumors from this method, we identified recurrent somatic alterations common across MCC and alterations specific to each class of tumor, associated with differences in overall survival. Finally, comparing the molecular and clinical data from these patients revealed a surprising association of immunosuppression with virus-negative MCC and significantly shortened overall survival. Conclusions These results demonstrate the value of high-confidence virus detection for identifying molecular mechanisms of UV and viral oncogenesis in MCC. Furthermore, integrating these data with clinical data revealed features that could impact patient outcome and improve our understanding of MCC risk factors.

Background The combination of antiangiogenic agents with immune checkpoint inhibitors could potentially overcome immune suppression driven by tumor angiogenesis. We report results from a phase IB study of ziv-aflibercept plus pembrolizumab in patients with advanced solid tumors.Methods This is a multicenter phase IB dose-escalation study of the combination of ziv-aflibercept (at 2–4 mg/kg) plus pembrolizumab (at 2 mg/kg) administered intravenously every 2 weeks with expansion cohorts in programmed cell death protein 1 (PD-1)/programmed death-ligand 1(PD-L1)-naïve melanoma, renal cell carcinoma (RCC), microsatellite stable colorectal cancer (CRC), and ovarian cancer. The primary objective was to determine maximum tolerated dose (MTD) and recommended dose of the combination. Secondary endpoints included overall response rate (ORR) and overall survival (OS). Exploratory objectives included correlation of clinical efficacy with tumor and peripheral immune population densities.Results Overall, 33 patients were enrolled during dose escalation (n=3) and dose expansion (n=30). No dose-limiting toxicities were reported in the initial dose level. Ziv-aflibercept 4 mg/kg plus pembrolizumab 2 mg/kg every 2 weeks was established as the MTD. Grade ≥3 adverse events occurred in 19/33 patients (58%), the most common being hypertension (36%) and proteinuria (18%). ORR in the dose-expansion cohort was 16.7% (5/30, 90% CI 7% to 32%). Complete responses occurred in melanoma (n=2); partial responses occurred in RCC (n=1), mesothelioma (n=1), and melanoma (n=1). Median OS was as follows: melanoma, not reached (NR); RCC, 15.7 months (90% CI 2.5 to 15.7); CRC, 3.3 months (90% CI 0.6 to 3.4); ovarian, 12.5 months (90% CI 3.8 to 13.6); other solid tumors, NR. Activated tumor-infiltrating CD8 T cells at baseline (CD8+PD1+), high CD40L expression, and increased peripheral memory CD8 T cells correlated with clinical response.Conclusion The combination of ziv-aflibercept and pembrolizumab demonstrated an acceptable safety profile with antitumor activity in solid tumors. The combination is currently being studied in sarcoma and anti-PD-1-resistant melanoma.Trial registration number NCT02298959.