PD-1 Blockade Induces Reactivation of Nonproductive T-Cell Responses Characterized by NF-κB Signaling in Patients with Pancreatic Cancer.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) trials have evaluated CTLA-4 and/or PD-(L)1 blockade in patients with advanced disease in which bulky tumor burden and limited time to develop antitumor T cells may have contributed to poor clinical efficacy. Here, we evaluated peripheral blood and tumor T cells from patients with PDAC receiving neoadjuvant chemoradiation plus anti-PD-1 (pembrolizumab) versus chemoradiation alone. We analyzed whether PD-1 blockade successfully reactivated T cells in the blood and/or tumor to determine whether lack of clinical benefit could be explained by lack of reactivated T cells versus other factors. EXPERIMENTAL DESIGN: We used single-cell transcriptional profiling and TCR clonotype tracking to identify TCR clonotypes from blood that match clonotypes in the tumor. RESULTS: PD-1 blockade increases the flux of TCR clonotypes entering cell cycle and induces an IFNγ signature like that seen in patients with other GI malignancies who respond to PD-1 blockade. However, these reactivated T cells have a robust signature of NF-κB signaling not seen in cases of PD-1 antibody response. Among paired samples between blood and tumor, several of the newly cycling clonotypes matched activated T-cell clonotypes observed in the tumor. CONCLUSIONS: Cytotoxic T cells in the blood of patients with PDAC remain sensitive to reinvigoration by PD-1 blockade, and some have tumor-recognizing potential. Although these T cells proliferate and have a signature of IFN exposure, they also upregulate NF-κB signaling, which potentially counteracts the beneficial effects of anti-PD-1 reinvigoration and marks these T cells as non-productive contributors to antitumor immunity. See related commentary by Lander and DeNardo, p. 474.

Safety and effectiveness of combination versus monotherapy with immune checkpoint inhibitors in patients with preexisting autoimmune diseases.

Patients with preexisting autoimmune disease (pAID) are generally excluded from clinical trials for immune checkpoint inhibitors (ICIs) for cancer due to concern of flaring pAID. In this multi-center, retrospective observational study, we compared safety of ICI combination (two ICI agents) versus monotherapy in cancer patients with pAIDs. The primary outcome was time to AEs (immune-related adverse events (irAEs) and/or pAID flares), with progression-free survival (PFS) and overall survival as secondary outcomes. Sixty-four of 133 patients (48%) received ICI combination and 69 (52%) monotherapy. Most had melanoma (32%) and lung cancer (31%). Most common pAIDs were rheumatic (28%) and dermatologic (23%). Over a median follow-up of 15 months (95%CI, 11-18 mo), the cumulative incidence of any-grade irAEs was higher for combination compared to monotherapy (subdistribution hazard ratio (sHR) 2.27, 95%CI 1.35-3.82). No statistically significant difference was observed in high-grade irAEs (sHR 2.31 (0.95-5.66), P = .054) or the cumulative incidence of pAID flares. There was no statistically significant difference for melanoma PFS between combination versus monotherapy (23.2 vs. 17.1mo, P = .53). The combination group was more likely to discontinue or hold ICI, but > 50% of the combination group was still able to continue ICI therapy. No treatment-related deaths occurred. In our cohort with pAIDs, patients had a tolerable toxicity profile with ICI combination therapy. Our results support the use of ICI combination if deemed necessary for cancer therapy in patients with pAIDs, since the ICI toxicities were comparable to monotherapy, able to be effectively managed and mostly did not require ICI interruption.

The Cholangiocarcinoma in the Young (CITY) Study: Tumor Biology, Treatment Patterns, and Survival Outcomes in Adolescent Young Adults With Cholangiocarcinoma.

PURPOSE: Increased awareness of the distinct tumor biology for adolescents and young adults (AYAs) with cancer has led to improvement in outcomes for this population. However, in cholangiocarcinoma (CCA), a paucity of data exist on the AYA population. To our knowledge, we present the largest study to date on AYA disease biology, treatment patterns, and survival outcomes in CCA. METHODS: A multi-institutional cohort of patients with CCA diagnosed with intrahepatic cholangiocarcinoma (ICC) or extrahepatic cholangiocarcinoma (ECC) was used for analysis. Retrospective chart review was conducted on patients who were 50 years old and younger (young; n = 124) and older than 50 years (older; n = 723). RESULTS: Among 1,039 patients screened, 847 patients met eligibility (72% ICC, 28% ECC). Young patients had a larger median tumor size at resection compared with older patients (4.2 v 3.6 cm; P = .048), more commonly had N1 disease (65% v 43%; P = .040), and were more likely to receive adjuvant therapy (odds ratio, 4.0; 95% CI, 1.64 to 9.74). Tumors of young patients were more likely to harbor an FGFR2 fusion, BRAF mutation, or ATM mutation (P < .05 for each). Young patients were more likely to receive palliative systemic therapy (96% v 69%; P < .001), targeted therapy (23% v 8%; P < .001), and treatment on a clinical trial (31% v 19%; P = .004). Among patients who presented with advanced disease, young patients had a higher median overall survival compared with their older counterparts (17.7 v 13.5 months; 95% CI, 12.6 to 22.6 v 11.4 to 14.8; P = .049). CONCLUSION: Young patients with CCA had more advanced disease at resection, more commonly received both adjuvant and palliative therapies, and demonstrated improved survival compared with older patients. Given the low clinical trial enrollment and poor outcomes among some AYA cancer populations, data to the contrary in CCA are highly encouraging.

Prospective Correlation of Magnetic Resonance Tumor Regression Grade With Pathologic Outcomes in Total Neoadjuvant Therapy for Rectal Adenocarcinoma.

PURPOSE: Total neoadjuvant therapy (TNT) is a newly established standard treatment for rectal adenocarcinoma. Current methods to communicate magnitudes of regression during TNT are subjective and imprecise. Magnetic resonance tumor regression grade (MR-TRG) is an existing, but rarely used, regression grading system. Prospective validation of MR-TRG correlation with pathologic response in patients undergoing TNT is lacking. Utility of adding diffusion-weighted imaging to MR-TRG is also unknown. METHODS: We conducted a multi-institutional prospective imaging substudy within NRG-GI002 (ClinicalTrials.gov identifier: NCT02921256) examining the ability of MR-based imaging to predict pathologic complete response (pCR) and correlate MR-TRG with the pathologic neoadjuvant response score (NAR). Serial MRIs were needed from 110 patients. Three radiologists independently, then collectively, reviewed each MRI for complete response (mriCR), which was tested for positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity with pCR. MR-TRG was examined for association with the pathologic NAR score. All team members were blinded to pathologic data. RESULTS: A total of 121 patients from 71 institutions met criteria: 28% were female (n = 34), 84% White (n = 101), and median age was 55 (24-78 years). Kappa scores for T- and N-stage after TNT were 0.38 and 0.88, reflecting fair agreement and near-perfect agreement, respectively. Calling an mriCR resulted in a kappa score of 0.82 after chemotherapy and 0.56 after TNT reflected near-perfect agreement and moderate agreement, respectively. MR-TRG scores were associated with pCR (P < .01) and NAR (P < .0001), PPV for pCR was 40% (95% CI, 26 to 53), and NPV was 84% (95% CI, 75 to 94). CONCLUSION: MRI alone is a poor tool to distinguish pCR in rectal adenocarcinoma undergoing TNT. However, the MR-TRG score presents a now validated method, correlated with pathologic NAR, which can objectively measure regression magnitude during TNT.

Profiling of Natural Killer Interactions With Cancer Cells Using Mass Cytometry.

We developed a comprehensive method for functional assessment of the changes in immune populations and killing activity of peripheral blood mononuclear cells after cocultures with cancer cells using mass cytometry. In this study, a 43-marker mass cytometry panel was applied to a coculture of immune cells from healthy donors' peripheral blood mononuclear cells with diverse cancer cell lines. DNA content combined with classical CD45 surface staining was used as gating parameters for cocultures of immune cells (CD45high/DNAlow) with hematological (CD45low/DNAhigh) and solid cancer cell lines (CD45neg/DNAhigh). This strategy allows for universal discrimination of cancer cells from immune populations without the need for a specific cancer cell marker and simultaneous assessment of phenotypical changes in both populations. The use of mass cytometry allows for simultaneous detection of changes in natural killer, natural killer T cell, and T cell phenotypes and degranulation of immune populations upon target recognition, analysis of target cells for cytotoxic protein granzyme B content, and cancer cell death. These findings have broad applicability in research and clinical settings with the aim to phenotype and assess functional changes following not only NK-cancer cell interactions but also the effect of those interactions on other immune populations.

Molecular profiling and treatment pattern differences between intrahepatic and extrahepatic cholangiocarcinoma.

BACKGROUND: Treatment patterns for intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) differ, but limited studies exist comparing them. This study examines differences in molecular profiling rates and treatment patterns in these populations, focusing on use of adjuvant, liver-directed, targeted, and investigational therapies. METHODS: This multicenter collaboration included patients with ICC or ECC treated at 1 of 8 participating institutions. Retrospective data were collected on risk factors, pathology, treatments, and survival. Comparative statistical tests were 2-sided. RESULTS: Among 1039 patients screened, 847 patients met eligibility (ICC = 611, ECC = 236). Patients with ECC were more likely than those with ICC to present with early stage disease (53.8% vs 28.0%), undergo surgical resection (55.1% vs 29.8%), and receive adjuvant chemoradiation (36.5% vs 4.2%) (all P < .00001). However, they were less likely to undergo molecular profiling (50.3% vs 64.3%) or receive liver-directed therapy (17.9% vs 35.7%), targeted therapy (4.7% vs 18.9%), and clinical trial therapy (10.6% vs 24.8%) (all P < .001). In patients with recurrent ECC after surgery, the molecular profiling rate was 64.5%. Patients with advanced ECC had a shorter median overall survival than those with advanced ICC (11.8 vs 15.1 months; P < .001). CONCLUSIONS: Patients with advanced ECC have low rates of molecular profiling, possibly in part because of insufficient tissue. They also have low rates of targeted therapy use and clinical trial enrollment. While these rates are higher in advanced ICC, the prognosis for both subtypes of cholangiocarcinoma remains poor, and a pressing need exists for new effective targeted therapies and broader access to clinical trials.

Programmatic Precision Oncology Decision Support for Patients With Gastrointestinal Cancer.

PURPOSE: With the growing number of available targeted therapeutics and molecular biomarkers, the optimal care of patients with cancer now depends on a comprehensive understanding of the rapidly evolving landscape of precision oncology, which can be challenging for oncologists to navigate alone. METHODS: We developed and implemented a precision oncology decision support system, GI TARGET, (Gastrointestinal Treatment Assistance Regarding Genomic Evaluation of Tumors) within the Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute. With a multidisciplinary team, we systematically reviewed tumor molecular profiling for GI tumors and provided molecularly informed clinical recommendations, which included identifying appropriate clinical trials aided by the computational matching platform MatchMiner, suggesting targeted therapy options on or off the US Food and Drug Administration-approved label, and consideration of additional or orthogonal molecular testing. RESULTS: We reviewed genomic data and provided clinical recommendations for 506 patients with GI cancer who underwent tumor molecular profiling between January and June 2019 and determined follow-up using the electronic health record. Summary reports were provided to 19 medical oncologists for patients with colorectal (n = 198, 39%), pancreatic (n = 124, 24%), esophagogastric (n = 67, 13%), biliary (n = 40, 8%), and other GI cancers. We recommended ≥ 1 precision medicine clinical trial for 80% (406 of 506) of patients, leading to 24 enrollments. We recommended on-label and off-label targeted therapies for 6% (28 of 506) and 25% (125 of 506) of patients, respectively. Recommendations for additional or orthogonal testing were made for 42% (211 of 506) of patients. CONCLUSION: The integration of precision medicine in routine cancer care through a dedicated multidisciplinary molecular tumor board is scalable and sustainable, and implementation of precision oncology recommendations has clinical utility for patients with cancer.

Multiple high-grade and rare immune-related adverse events in a colon cancer patient with genomic and cytokine profiling.

We report a case of multiple high-grade and rare immune-related adverse events (irAEs) in a patient with microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). A middle-aged MSI-H mCRC patient with metastases to the lungs and lymph nodes received several lines of chemotherapy and immunotherapy and developed five different high-grade irAEs during immunotherapy, including lymphadenitis, pneumonitis, hypophysitis, thyroiditis and transverse myelitis. Genomic profiling revealed high tumor mutational burden of 43 Muts/Mb. Cytokine profiling showed a threefold increase in MMP-9 shortly prior to the onset of lymphadenitis and a fourfold increase of Ang-1 1 week after the resolution of lymphadenitis. Further studies are warranted to investigate the association of MSI-H mCRC with irAEs and the role of cytokines in predicting irAEs.

Immune-related adverse events (irAEs) are a potential side effect of taking immunotherapy treatment for cancer. We report a case of a patient with a highly mutated form of metastatic colon cancer who developed five unique and severe irAEs while receiving immunotherapy. The patient developed inflammation of the lymph nodes, lungs, pituitary gland, thyroid and spinal cord. Genetic testing showed that the tumor was highly mutated (43 Muts/Mb). Analysis of cell signaling proteins called cytokines revealed that MMP-9 sharply increased before the onset of lymphadenitis and Ang-1 sharply increased after its resolution. Further research is needed to understand the relationship between highly mutated colon cancer and irAEs as well as the role of cytokines in predicting the onset and resolution of irAEs.

First-in-Human Phase I/II ICONIC Trial of the ICOS Agonist Vopratelimab Alone and with Nivolumab: ICOS-High CD4 T-Cell Populations and Predictors of Response.

PURPOSE: The first-in-human phase I/II ICONIC trial evaluated an investigational inducible costimulator (ICOS) agonist, vopratelimab, alone and in combination with nivolumab in patients with advanced solid tumors. PATIENTS AND METHODS: In phase I, patients were treated with escalating doses of intravenous vopratelimab alone or with nivolumab. Primary objectives were safety, tolerability, MTD, and recommended phase II dose (RP2D). Phase II enriched for ICOS-positive (ICOS+) tumors; patients were treated with vopratelimab at the monotherapy RP2D alone or with nivolumab. Pharmacokinetics, pharmacodynamics, and predictive biomarkers of response to vopratelimab were assessed. RESULTS: ICONIC enrolled 201 patients. Vopratelimab alone and with nivolumab was well tolerated; phase I established 0.3 mg/kg every 3 weeks as the vopratelimab RP2D. Vopratelimab resulted in modest objective response rates of 1.4% and with nivolumab of 2.3%. The prospective selection for ICOS+ tumors did not enrich for responses. A vopratelimab-specific peripheral blood pharmacodynamic biomarker, ICOS-high (ICOS-hi) CD4 T cells, was identified in a subset of patients who demonstrated greater clinical benefit versus those with no emergence of these cells [overall survival (OS), P = 0.0025]. A potential genomic predictive biomarker of ICOS-hi CD4 T-cell emergence was identified that demonstrated improvement in clinical outcomes, including OS (P = 0.0062). CONCLUSIONS: Vopratelimab demonstrated a favorable safety profile alone and in combination with nivolumab. Efficacy was observed only in a subset of patients with a vopratelimab-specific pharmacodynamic biomarker. A potential predictive biomarker of response was identified, which is being prospectively evaluated in a randomized phase II non-small cell lung cancer trial. See related commentary by Lee and Fong, p. 3633.

Phase IB study of ziv-aflibercept plus pembrolizumab in patients with advanced solid tumors.

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.

Effect of corticosteroid dosing on outcomes in high-grade immune checkpoint inhibitor hepatitis.

BACKGROUND AND AIMS: Consensus guidelines recommend high-dose corticosteroids (1-2 mg/kg/day methylprednisolone equivalents) for treating grade ≥3 immune checkpoint inhibitor (ICI) hepatitis. We examined the effect of corticosteroid dosing on time to alanine aminotransferase (ALT) normalization, need for additional immunosuppression, and steroid-related complications. APPROACH AND RESULTS: We conducted a retrospective cohort study of 215 ICI-treated patients from 2010 to 2020 who developed grade ≥3 (ALT > 200 U/L) ICI hepatitis. Patients were grouped by initial corticosteroid dose (≥1.5 mg/kg or <1.5 mg/kg methylprednisolone equivalents). Propensity scores were calculated predicting the risk of receiving the higher steroid dose and used in inverse probability of treatment weighted (IPTW) logistic or Cox regression. The 87 patients in the ≥1.5 mg/kg group received higher initial (2.0 vs. 0.8 mg/kg/day, p < 0.001) and maximum (2.0 vs. 1.0 mg/kg/day, p < 0.001) steroid doses than the 128 patients in the <1.5 mg/kg group. There was no difference between the higher versus lower-dose groups in development of steroid-refractory hepatitis (OR 1.22, 95% CI 0.79-1.89, p = 0.365) on IPTW-logistic regression. In patients with steroid-responsive disease, there was no difference between the two groups in time to ALT normalization using either standard Cox regression (HR 1.02, 95% CI 0.72-1.45, p = 0.903) or IPTW-Cox regression (HR 1.09, 95% CI 0.78-1.51, p = 0.610). The ≥1.5 mg/kg group had longer exposure to corticosteroids (median 60 vs. 44 days, p = 0.005) and higher incidences of infection (18.4% vs. 7.0%, relative risk [RR] 2.6, 95% CI 1.2-5.6, p = 0.011) and hyperglycemia requiring treatment (23.3% vs. 7.8%, RR 3.0, 95% CI 1.5-6.0, p = 0.001). CONCLUSIONS: In patients with high-grade ICI hepatitis, initial treatment with 1 mg/kg/day methylprednisolone equivalents provides similar hepatitis outcomes with reduced risk of steroid-related complications when compared with higher-dose regimens.

Immune-related adverse events and kidney function decline in patients with genitourinary cancers treated with immune checkpoint inhibitors.

BACKGROUND: In patients with genitourinary cancers, the effect of immune checkpoint inhibitors (ICIs) on kidney function is unknown. PATIENTS AND METHODS: This is a retrospective cohort study of patients with renal cell carcinoma (RCC) and urothelial carcinoma who received ICIs at two major cancer centers between 2012 and 2018. Cumulative incidence and Fine and Gray subdistribution hazard models were performed to determine predictors of the co-primary outcomes, (1) acute kidney injury (AKI) and (2) sustained estimated glomerular filtration rate (eGFR) loss, defined as a >20% decline in eGFR sustained ≥90 days. We also determined the association between immune-related adverse events (irAE) and adverse kidney outcomes among patients surviving ≥1 year. RESULTS: 637 patients were included; 320 (50%) patients had RCC and 317 (50%) patients had urothelial carcinoma. Half of the cohort had eGFR<60 mL/min/1.73 m2 at baseline. irAEs, AKI, and sustained eGFR loss were common, occurring in 33%, 25% and 16%, respectively. Compared to patients with urothelial carcinoma, patients with RCC were more likely to develop irAEs (aHR 1.61, 95% CI 1.20-2.18) and sustained eGFR loss (aHR 1.97, 95% CI 1.24-3.12), but not AKI (aHR 1.53, 95% CI 0.97-2.41). Among patients surviving ≥1 years, experiencing a non-renal irAE was associated with a significantly higher risk of sustained eGFR loss (aHR 1.71, 95% CI 1.14-2.57). CONCLUSION: AKI and sustained eGFR loss are common in patients with genitourinary cancers receiving ICIs. irAEs may be a novel risk factor for kidney function decline among patients receiving ICIs.

Early Use of High-Dose Glucocorticoid for the Management of irAE Is Associated with Poorer Survival in Patients with Advanced Melanoma Treated with Anti-PD-1 Monotherapy.

PURPOSE: Programmed cell death receptor-1 (PD-1) inhibitors are frontline therapy in advanced melanoma. Severe immune-related adverse effects (irAEs) often require immunosuppressive treatment with glucocorticoids (GCCs), but GCC use and its correlation with patient survival outcomes during anti-PD-1 monotherapy remains unclear. EXPERIMENTAL DESIGN: In this multicenter retrospective analysis, patients treated with anti-PD-1 monotherapy between 2009 and 2019 and detailed GCC use, data were identified from five independent cohorts, with median follow-up time of 206 weeks. IrAEs were tracked from the initiation of anti-PD-1 until disease progression, initiation of a new therapy, or last follow-up. Correlations between irAEs, GCC use, and survival outcomes were analyzed. RESULTS: Of the entire cohort of 947 patients, 509 (54%) developed irAEs. In the MGH cohort [irAE(+) n = 90], early-onset irAE (within 8 weeks of anti-PD-1 initiation) with high-dose GCC use (≥60-mg prednisone equivalent once a day) was independently associated with poorer post-irAE PFS/OS (progression-free survival/overall survival) [post-irAE PFS: HR, 5.37; 95% confidence interval (CI), 2.10-13.70; P < 0.001; post-irAE OS: HR, 5.95; 95% CI, 2.20-16.09; P < 0.001] compared with irAEs without early high-dose GCC use. These findings were validated in the combined validation cohort [irAE(+) n = 419, post-irAE PFS: HR, 1.69; 95% CI, 1.04-2.76; P = 0.04; post-irAE OS: HR, 1.97; 95% CI, 1.15-3.39; P = 0.01]. Similar findings were also observed in the 26-week landmark analysis for post-irAE-PFS but not for post-irAE-OS. A sensitivity analysis using accumulated GCC exposure as the measurement achieved similar results. CONCLUSIONS: Early high-dose GCC use was associated with poorer PFS and OS after irAE onset. Judicious use of GCC early during anti-PD-1 monotherapy should be considered. Further prospective randomized control clinical trials designed to explore alternative irAE management options are warranted.

Use of Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: Initial Results From the Pembrolizumab Arm of a Phase 2 Randomized Clinical Trial.

IMPORTANCE: Total neoadjuvant therapy (TNT) is often used to downstage locally advanced rectal cancer (LARC) and decrease locoregional relapse; however, more than one-third of patients develop recurrent metastatic disease. As such, novel combinations are needed. OBJECTIVE: To assess whether the addition of pembrolizumab during and after neoadjuvant chemoradiotherapy can lead to an improvement in the neoadjuvant rectal (NAR) score compared with treatment with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) and chemoradiotherapy alone. DESIGN, SETTING, AND PARTICIPANTS: In this open-label, phase 2, randomized clinical trial (NRG-GI002), patients in academic and private practice settings were enrolled. Patients with stage II/III LARC with distal location (cT3-4 ≤ 5 cm from anal verge, any N), with bulky disease (any cT4 or tumor within 3 mm of mesorectal fascia), at high risk for metastatic disease (cN2), and/or who were not candidates for sphincter-sparing surgery (SSS) were stratified based on clinical tumor and nodal stages. Trial accrual opened on August 1, 2018, and ended on May 31, 2019. This intent-to-treat analysis is based on data as of August 2020. INTERVENTIONS: Patients were randomized (1:1) to neoadjuvant FOLFOX for 4 months and then underwent chemoradiotherapy (capecitabine with 50.4 Gy) with or without intravenous pembrolizumab administered at a dosage of 200 mg every 3 weeks for up to 6 doses before surgery. MAIN OUTCOMES AND MEASURES: The primary end point was the NAR score. Secondary end points included pathologic complete response (pCR) rate, SSS, disease-free survival, and overall survival. This report focuses on end points available after definitive surgery (NAR score, pCR, SSS, clinical complete response rate, margin involvement, and safety). RESULTS: A total of 185 patients (126 [68.1%] male; mean [SD] age, 55.7 [11.1] years) were randomized to the control arm (CA) (n = 95) or the pembrolizumab arm (PA) (n = 90). Of these patients, 137 were evaluable for NAR score (68 CA patients and 69 PA patients). The mean (SD) NAR score was 11.53 (12.43) for the PA patients (95% CI, 8.54-14.51) vs 14.08 (13.82) for the CA patients (95% CI, 10.74-17.43) (P = .26). The pCR rate was 31.9% in the PA vs 29.4% in the CA (P = .75). The clinical complete response rate was 13.9% in the PA vs 13.6% in the CA (P = .95). The percentage of patients who underwent SSS was 59.4% in the PA vs 71.0% in the CA (P = .15). Grade 3 to 4 adverse events were slightly increased in the PA (48.2%) vs the CA (37.3%) during chemoradiotherapy. Two deaths occurred during FOLFOX: sepsis (CA) and pneumonia (PA). No differences in radiotherapy fractions, FOLFOX, or capecitabine doses were found. CONCLUSIONS AND RELEVANCE: Pembrolizumab added to chemoradiotherapy as part of total neoadjuvant therapy was suggested to be safe; however, the NAR score difference does not support further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02921256.

Myeloid Cell Infiltration Correlates With Prognosis in Cholangiocarcinoma and Varies Based on Tumor Location.

Cholangiocarcinoma (CC) is an uncommon malignancy with increasing incidence and dismal prognosis. We conducted a comprehensive analysis of the CC tumor immune microenvironment (TIME) based on tumor location to identify therapeutic targets. We hypothesized that the TIME of CC would vary by primary tumor location and that high tumor infiltration by CD8+ T cells and low infiltration by M2 macrophages would be associated with improved survival. A retrospective analysis was conducted of 99 CC tumor samples surgically resected between 2000 and 2014. Tissue microarrays were constructed from each tumor and stained by immunohistochemistry for 24 markers of immune cells, immune activation or inhibition, programmed cell death-ligand 1, and mesothelin. Most tumors were amply infiltrated with by CD4+, CD8+, and FoxP3+ T cells, as well as by myeloid cells. Mesothelin expression ≥1+ by immunohistochemistry was found in 68% of tumors. We identified higher densities of M1 macrophages in primary distal extrahepatic CC, as well as metastatic lesions. Mesothelin expression was also significantly higher in distal extrahepatic CC. There was no association with survival of infiltration by CD4+, CD8+, or FoxP3+ T cells, mesothelin expression, or programmed cell death-ligand 1 percentage expression, however, high CD14+ myeloid cells and high CD163+ M2 macrophages were associated with worse survival. In conclusion, the CC TIME is a heterogenous milieu highly infiltrated by innate and adaptive immune cells, which differs based on primary tumor location and between primary tumors and metastatic lesions. The correlation of intratumoral M2 macrophages and myeloid cells with a worse prognosis may suggest promising immunotherapeutic targets in CC.

Pancreatic acinar cell carcinoma: A multi-center series on clinical characteristics and treatment outcomes.

BACKGROUND: Acinar cell carcinoma (ACC) is a very rare tumor of the exocrine pancreas, representing less than 1% of all pancreatic malignancies. The majority of data regarding ACC are limited to small case series. METHODS: This is a retrospective study conducted at a large healthcare system from 1996 to 2019. Patients with pathologically confirmed ACC were included, and demographic data, tumor characteristics, and treatment outcomes were abstracted by chart review. Survival curves were obtained by using the Kaplan-Meier method and compared using the log-rank test. RESULTS: Sixty-six patients with ACC were identified. The median patient age at diagnosis was 64, and 42% presented with metastatic disease. The majority presented with abdominal pain or pancreatitis (69%), and laboratory parameters did not correlate with tumor size, metastatic disease, or survival. Several somatic abnormalities were noted in tumors (BRCA2, TP53, and mismatch-repair genes). In patients with localized disease that underwent resection, the median time to develop metastatic lesions was 13 months. The median overall survival (OS) was 24.7 months from diagnosis, with a survival difference based on metastatic disease at diagnosis (median 15 vs 38 mos). Surgery was associated with improved survival in non-metastatic cases (p = 0.006) but not metastatic cases (p = 0.22), and chemotherapy showed OS benefit in metastatic disease (p < 0.01). Patients with metastatic ACC treated after 2010 utilized more platinum-based agents, and there was a OS benefit to FOLFOX or FOLFIRINOX chemotherapy compared to gemcitabine or capecitabine-based regimens (p = 0.006). CONCLUSION: Pancreatic ACC patients often present with advanced disease. Surgery was associated with survival benefit among patients presenting with localized disease. The use of FOLFOX or FOLFIRINOX chemotherapy regimens was associated with improved OS in metastatic patients. These data add to our knowledge in this rare malignancy, and improves understanding about the genomic underpinnings, prognosis and treatment for acinar cancers.

A Randomized Trial of Combined PD-L1 and CTLA-4 Inhibition with Targeted Low-Dose or Hypofractionated Radiation for Patients with Metastatic Colorectal Cancer.

PURPOSE: Prospective human data are lacking regarding safety, efficacy, and immunologic impacts of different radiation doses administered with combined PD-L1/CTLA-4 blockade. PATIENTS AND METHODS: We 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. RESULTS: Eighteen 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. CONCLUSIONS: We 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.

Cytokine changes during immune-related adverse events and corticosteroid treatment in melanoma patients receiving immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) often cause immune-related adverse events (irAEs), most of which are treated with corticosteroids despite evidence suggesting that corticosteroids may blunt antitumor efficacy. We sought to identify cytokine changes that correlate with irAEs and study the impact of corticosteroid treatment on cytokine levels. METHODS: We analyzed expression of 34 cytokines in 52 melanoma patients who developed irAEs during therapy with ICIs. Luminex serum assay was performed at baseline, 1, 2, and 3 months after starting ICI. Baseline cytokine levels and longitudinal log2 fold-change was compared with incidence and grade of irAEs. Cytokine patterns were compared between patients based on development of irAEs and steroid treatment. RESULTS: There were no differences in baseline cytokine levels between patients who developed grade 1-2 irAEs (N = 28) vs. grade 3-4 irAEs (N = 24). Dermatitis patients (N = 8) had significantly higher baseline Ang-1 (p = 0.006) and CD40L (p = 0.005). Pneumonitis patients (N = 4) had significantly higher baseline IL-17 (p = 0.009). Colitis patients (N = 8) had a trend toward decreased GCSF (p = 0.08). Through Spearman's correlation analysis, patients who developed irAEs without receiving corticosteroids (N = 23) exhibited harmonization of cytokine fold-change, with 0/276 pairwise comparisons demonstrating significant divergence. In contrast, corticosteroid treatment in patients with irAEs (N = 15) altered fold-change to a discordant pattern (42/276 diverged, 15.2%). This discordant cytokine pattern in patients receiving corticosteroids is similar to the cytokine pattern in patients who did not develop irAEs (N = 8) during the longitudinal profiling period (41/276, 14.9%). CONCLUSIONS: Baseline levels of certain cytokines correlate with specific irAEs in melanoma patients receiving ICIs. irAEs drive a concordant pattern of cytokine fold-change, which is disrupted by corticosteroid treatment.