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Biliary tract cancers (BTCs) are rare and aggressive tumors that typically present at an advanced stage when surgical resection is no longer considered a therapeutic option. While gemcitabine and cisplatin have been the mainstay of treatment, unique chemotherapy combination strategies, targeted therapies, and immunotherapies have had some clinical efficacy and remain promising areas for clinical research. The use of molecular profiling of BTCs has facilitated the development and subsequent clinical application of novel targeted therapy compounds. Among the many genomic alterations identified in BTCs, molecular abnormalities in the fibroblast growth factor receptor (FGFR), isocitrate dehydrogenase (IDH), human epidermal growth factor receptor 2 (HER2), and BRAF have been successfully targeted therapeutically in clinical trials. Furthermore, the expanded use of new chemotherapy combinations, targeted therapies, and immunotherapies into alternate clinical settings such as in the neoadjuvant and adjuvant spaces is an area of active investigation. The management of BTCs is rapidly evolving. In this article, we review the emerging targets and therapies in BTC.

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 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.

BACKGROUND: Neoadjuvant chemoradiotherapy can provide downstaging and improve margin negativity for borderline resectable and resectable pancreatic adenocarcinoma [(B)RPC]. Little is known about the relative efficacy of capecitabine (CAPE)-based vs. gemcitabine (GEM)-based 3-week chemoradiation (3WCRT) with 36 Gy in 15 fractions. This study aimed to compare the odds of achieving surgical resection, time to progression (TTP), and overall survival (OS) of patients treated with 3WCRT with concurrent CAPE versus GEM. METHODS: A retrospective cohort study was conducted, examining medical records from a single center for patients with (B)RPC treated with 3WCRT between 1/2009–12/2020. Odd ratios (OR) of achieving surgical resection were estimated using logistic regression for univariable and multivariable analyses. Median TTP (mTTP) and median OS (mOS) were estimated using the Kaplan-Meier method. Cox proportional hazards analysis was conducted to estimate hazard ratios (HR) of progression and survival in univariable and multivariable analyses. RESULTS: Thirty-one patients were included in the analysis. Twenty-two (71%) patients were treated with CAPE, while 9 (29%) were treated with GEM. All patients in the GEM group were borderline resectable, vs. 18 (82%) patients in the CAPE group, P=0.30. Nineteen (86%) patients in the CAPE group were treated with neoadjuvant FOLFIRINOX, vs. 4 (44%) patients in the GEM group, P=0.03. The CAPE group had higher odds of achieving surgical resection [OR =9.33; 95% confidence interval (CI): 1.50–58.20]. Adjusting for covariates, the odds of achieving surgical resection were still statistically higher in the CAPE group vs. the GEM group (OR =25.34; 95% CI: 1.14–563.72). The CAPE group had superior mTTP compared to the GEM group (15.4 months, 95% CI: 4.9–71.1 vs. 4.0 months, 95% CI: 0.4–14.5; P=0.01), corresponding to a hazard ratio of 0.33 (95% CI: 0.14–0.81). Adjusting for covariates this effect persisted; the adjusted hazard ratio (AHR) for progression was 0.24 (95% CI: 0.08–0.77). Cox proportional hazards analysis also demonstrated that the CAPE group had superior OS compared to the GEM group in unadjusted (HR =0.13; 95% CI: 0.04–0.40) and adjusted models (HR =0.13, 95% CI: 0.03–0.52). CONCLUSIONS: For neoadjuvant 3WCRT, this hypothesis-generating study suggests concurrent CAPE may be a more effective radiosensitizer than GEM for patients with (B)RPC.

Aim: Cytokine release syndrome (CRS) is an infrequently described immune-related adverse event of checkpoint inhibitors (CPI). CPI-induced CRS typically presents with fevers, hemodynamic instability and organ dysfunction within 2 weeks of the last treatment cycle. Case study: We report an unusual case of delayed and severe CRS occurring postoperatively in a patient with hepatic-limited metastatic colorectal cancer who received neoadjuvant immunotherapy. After a negative workup for alternative causes, he received prolonged corticosteroid treatment with symptom resolution. Conclusion: CPI-induced CRS can mimic sepsis and clinicians should maintain a high-index of suspicion to diagnose this immune-related adverse event early and initiate appropriate treatment. As use of perioperative immunotherapy increases, the potential role of surgery to trigger CRS in this case warrants further investigation.

AR is an oncogenic driver of hepatocellular carcinoma but AR-targeted therapy is limited by feedback activation of the AKT-mTOR pathway. Co-targeting of mTORC1 and AR might be an effective approach to HCC treatment. Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and a leading cause of cancer deaths worldwide. HCC is a male-dominant cancer with a male:female ratio of up to 7:1. The androgen receptor (AR) is the male hormone receptor known as a major oncogenic driver of prostate cancer. Although AR has been linked to the sexual dimorphism of HCC, clinical trials with AR-targeted agents failed to generate survival benefits. Recent studies provide new insights into the role of AR in liver tumorigenesis and therapeutic responses. Herein, we review current understanding of AR signaling in HCC and feedback mechanisms that limit response to AR blockade. New AR-targeting strategies that might improve outcomes in HCC therapies are also discussed.

BackgroundOX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949.MethodsPhase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7–1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics.ResultsEighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1–9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting >6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs.ConclusionNo safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors.Trial registration numberNCT02923349.

Background Glutamate signaling activates MAPK and PI3K/AKT pathways in tumor cells. Treatment with riluzole, a glutamate release inhibitor, has been previously shown to be safe in melanoma patients and produced biologic effects, but did not lead to radiographic responses, possibly due to poor pharmacokinetic properties. Therefore, we conducted a phase Ib trial to determine the safety and tolerability of the combination of the riluzole prodrug troriluzole (BHV-4157, trigriluzole) and the PD-1 antibody nivolumab in patients with advanced solid tumors. Methods Patients with advanced or refractory solid tumors and measurable disease per RECIST 1.1 were treated with increasing doses of troriluzole using a semi-Bayesian modified toxicity probability interval dose escalation procedure. Troriluzole monotherapy was orally self-administered for a 14-day lead-in period followed by continuation of troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Endpoints included safety, pharmacokinetics (PK) and efficacy. Results We enrolled 14 patients with advanced solid tumors (melanoma = 3, NSCLC = 3, renal cell carcinoma = 2, bladder/urothelial = 2, ovarian cancer = 1, adenoid cystic carcinoma = 1, pleural mesothelial = 1, head and neck cancer = 1). Eleven patients had cancer progression on prior therapy with PD-1 or PD-L1 agent. Patients received troriluzole total daily doses from 140 to 560 mg (divided). The most common treatment-related adverse events (TRAE) occurring in ≥ 5 patients (> 35%) were transaminitis and increased lipase. DLT (dose-limiting toxicity) occurred in 3 patients: (1) grade 3 anorexia, (2) grade 3 fatigue and, (3) grade 3 atrial fibrillation. Six patients were treated at the MTD (maximum tolerated dose). No subjects discontinued treatment due to AEs. One response occurred (7%), which was a partial response in a subject who had PD-1 refractory disease. The 6-month PFS rate was 21%. PK data showed that the prodrug troriluzole was efficiently cleaved into riluzole by 2-h post-dosing in all dose cohorts tested. Conclusion The combination of troriluzole and nivolumab was safe and well-tolerated. The MTD of troriluzole was determined to be 420 mg total daily dose. The observed antitumor activity, primarily disease stabilization, is of interest in patients with PD-1 resistant tumors. Trial Registration ClinicalTrials.gov Identifier NCT03229278.

Cancer care has been greatly impacted during the COVID-19 pandemic. The number of cases and deaths caused by the COVID-19 pandemic continues to escalate throughout the United States and the world. Worldwide, over 150 million people have been diagnosed with the coronavirus and more than 3 million have died. Now that we have gained additional experience with COVID-19, we are starting to learn its full impact on oncology care and its effects on the practice of medicine and clinical research.

Background: Outcomes in advanced anal squamous cell carcinoma are poor, with few treatment options and controlled clinical trials. We evaluated the efficacy and safety of pembrolizumab in patients with advanced anal squamous cell carcinoma (cohort A) from the phase 2 KEYNOTE-158 study. Methods: Eligible patients enrolled in the ongoing non-randomised, multicohort, multicentre, phase 2 KEYNOTE-158 study, which was done across 38 centres worldwide, were aged 18 years or older; had histologically or cytologically confirmed advanced or metastatic anal squamous cell carcinoma; had previous failure of or intolerance to standard therapy or no standard therapy options; and had a PD-L1-evaluable tissue sample. Patients received pembrolizumab 200 mg intravenously every 3 weeks for 2 years, or until disease progression, unacceptable toxicity, investigator's decision to withdraw the patient from the study, or withdrawal of patient consent. The primary endpoint was objective response, as assessed by Response Evaluation Criteria in Solid Tumors version 1.1. Efficacy and safety analyses included all patients who received at least one dose of pembrolizumab. The trial is registered with ClinicalTrials.gov, NCT02628067. Findings: Between March 3, 2016, and July 23, 2018, 163 patients were screened, of whom 112 were enrolled and treated in the anal cancer cohort. 91 (81%) patients were female, 104 (93%) had M1 disease, and 75 (67%) had PD-L1-positive tumours. The median time from first dose to data cutoff (June 27, 2019) was 34·7 months (IQR 32·5–36·4). 12 (11%, 95% CI 6–18) patients had an objective response, including 11 (15%, 8–25) of 75 patients with PD-L1-positive tumours and one (3%; 0–17) of 30 patients with PD-L1-negative tumours. 68 (61%) patients had treatment-related adverse events (20 [18%] patients had grade 3–4 adverse events), the most common of which were fatigue (17 patients), diarrhoea (13), hypothyroidism (13), and nausea (13). Serious treatment-related adverse events occurred in 12 (11%) patients. 25 (22%) patients had immune-mediated adverse events, and one (1%) had an infusion reaction. There were no treatment-related deaths. Interpretation: Pembrolizumab monotherapy is a possible treatment option with a favourable benefit–risk ratio for patients with previously treated advanced anal squamous cell carcinoma who have no alternative satisfactory treatment options. Funding: Merck Sharp & Dohme.

BackgroundCabozantinib, a multiple receptor tyrosine kinase inhibitor, promotes an immune-permissive environment which might enhance the activity of immune checkpoint inhibitors. COSMIC-021 (NCT03170960), a multicenter phase 1b study, is evaluating the combination of cabozantinib with atezolizumab in advanced solid tumors; here we present efficacy and safety results in patients with triple negative breast cancer (TNBC), ovarian cancer (OC), and endometrial cancer (EC).MethodsEligible patients had locally advanced or metastatic TNBC, OC, or EC and had radiographically progressed on prior systemic anticancer therapy. One or two lines of prior therapy were permitted. Patients with OC were platinum resistant or refractory. Prior treatment with anti-PD-1 or anti-PD-L1 agents was allowed for patients with TNBC. Patients received cabozantinib, 40 mg PO QD, plus atezolizumab, 1200 mg IV Q3W. The primary endpoint was objective response rate (ORR) per RECIST 1.1 as assessed by investigator. Other endpoints included safety, duration of response (DOR), progression free survival (PFS), and overall survival (OS). CT/MRI scans were performed Q6W for the first year and Q12W thereafter.ResultsAs of February 19, 2021, 30–32 patients were enrolled in each of the cohorts. 47% of patients with TNBC, 47% with OC, and 40% with EC had received 2 lines of prior therapy. Median follow-up was 18.7 months, 20.8 months, and 19.0 months for the TNBC, OC, and EC cohorts, respectively. Grade 3/4 treatment-related adverse events occurred in 33% of patients with TNBC, 56% with OC, and 37% with EC. One Grade 5 treatment-related adverse event of pulmonary hemorrhage occurred in the TNBC cohort and one of encephalitis occurred in the OC cohort. Cabozantinib plus atezolizumab demonstrated clinical activity in all three tumor cohorts (table 1).Abstract 531 Table 1ConclusionsCabozantinib in combination with atezolizumab demonstrated encouraging clinical activity in patients with previously treated advanced cancers.AcknowledgementsMedical writing support provided by Suvajit Sen, PhD (Exelixis, Inc.)Trial RegistrationNCT03170960Ethics ApprovalYesConsentYes

BACKGROUND: MEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition. METHODS: This open-label phase II study randomized patients with BTC to atezolizumab (anti–PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS). RESULTS: Seventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35–0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination. CONCLUSION: The combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs. TRIAL REGISTRATION: ClinicalTrials.gov NCT03201458. FUNDING: National Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI’s Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Given the evidence that coordinate inhibition of AKT induces autophagy, we studied the combination of the AKT inhibitor, MK-2206 with hydroxychloroquine (HCQ) in patients with advanced solid tumors. Patients were treated with weekly MK-2206 (135 mg or 200 mg) plus HCQ (200 mg, 400 mg or 600 mg BID). Thirty-five patients were enrolled across 5 dose levels. Two DLTs of grade 3 maculo-papular rash were observed at dose level 2 (MK-2206 200 mg weekly plus HCQ at 400 mg BID) and 1 DLT of grade 3 fatigue at dose level 2B (MK-2206 135 mg weekly plus HCQ 600 mg BID). The maximum tolerated dose (MTD) was declared as dose level 2B. The most common adverse events attributed to MK-2206 were hyperglycemia (N = 18; 51%), fatigue (N = 17; 49%), maculo-papular rash (N = 16; 46%), diarrhea (N = 12; 34%), anorexia (N = 11; 31%), and nausea (N = 11; 31%). Patients experiencing adverse events attributed to HCQ were small in number (N = 13) and primarily included fatigue (N = 5; 14%) and maculo-papular rashes (N = 3; 9%). Statistically significant effects on the pharmacokinetic properties of MK-2206 were observed in combination with HCQ. In addition, the plasma concentrations of HCQ in the combination with MK-2206 were significantly higher than the plasma levels of HCQ as monotherapy in prior studies. The best overall response of stable disease was observed in 5/34 (15%) patients. The combination of MK-2206 and hydroxychloroquine was tolerable, but with substantial number of drug-related AEs and minimal evidence of antitumor activity.

PURPOSE/OBJECTIVE(S) Neoadjuvant chemoradiotherapy (CRT) serves to downstage and increase the rate of surgical resection for borderline resectable and resectable pancreatic adenocarcinoma ((B)RPC). Although conventional staging provides prognostic information, it remains a challenge to predict which patients will proceed with resection. We hypothesize that the severity of vessel involvement and the trajectory of CA19-9 levels after neoadjuvant treatment would associate with proceeding to resection. MATERIALS/METHODS Medical records were retrospectively reviewed at a single center for patients diagnosed with (B)RPC and treated with neoadjuvant CRT between 1/2005 and 12/2020. Progress notes were evaluated to determine if a patient proceeded to surgery and the trajectory of CA 19-9 levels in response to treatment. Radiologist notes were evaluated to determine the extent of mesenteric vessel (superior mesenteric artery, celiac axis, portal vein, hepatic artery, and superior mesenteric vein) involvement. A vessel involvement score was calculated as the sum of all vessels in contact with tumor: 1 point for each vessel, with partial (< 180 degrees) encasement of artery counting as 2 points. Odds ratios (OR) of proceeding to resection were computed with 95% confidence intervals (CI) for CA19-9 response to treatment. Ordinal logistic regression models were fit to estimate the impact of greater vessel involvement on the odds of NOT proceeding with surgery. RESULTS Forty-two (n = 42) patients were included in the analysis. The median age was 65 years (IQR: 61 to 71). 73% of patients were treated with 3600 cGy in 15 fractions (fx), 24% of patients were treated with 4500-5040 cGy in 25-28 fx, and 3% of patients were treated with 3300 cGy in 5 fx. 55% of patients were treated with neoadjuvant FOLFIRINOX and 45% of patients were treated with other regimens. 88% of patients were considered borderline resectable and 12% were resectable at the time of diagnosis. Patients with any decrease in CA19-9 levels after CRT had higher odds of proceeding with resection (OR = 21.0, 95% CI: 3.2 to 139.2). However, decrease in CA19-9 levels after upfront chemotherapy was not significantly associated with proceeding with resection (P = 0.91). The odds of NOT proceeding with resection after neoadjuvant CRT were 1.81 times higher (95% CI: 0.97 to 3.39) for each increase in vessel involvement score, however these findings were not statistically significant (P = 0.062). CONCLUSION Patients diagnosed with (B)RPC proceeding with CRT have different odds of proceeding to surgery based on their response to CRT and extent of vessel involvement. Post-CRT CA19-9 can help predict which patients may proceed to resection. Future investigations will develop nomograms for estimating odds of proceeding to surgery in larger datasets to help aid in patient counseling and multidisciplinary discussion.

BackgroundINCB086550 is an orally administered small molecule that binds PD-L1 and inhibits PD-1/PD-L1 interaction. Translational data demonstrating markers of immune activation in patients following INCB086550 were previously reported.1 Preliminary clinical data from this phase 1 study are presented below.MethodsAdult patients (≥18 years) with advanced solid tumors were enrolled into this open-label study. Patients had disease progression after standard available therapy or were intolerant of or ineligible for standard treatment. Measurable disease was required. A modified 3+3 dose-escalation design was employed, followed by dose expansions. The primary endpoints were safety and tolerability of INCB086550, identification of a pharmacologically active dose and/or MTD, and confirmation of the RP2D. Secondary endpoints included PK, pharmacodynamics, and efficacy as assessed by investigator-determined ORR and DCR (CR, PR, or SD ≥12 weeks).ResultsAs of 9Apr2021, 79 patients received treatment (Table 1); 57.0% were female, 62.0% had ≥2 prior lines of therapy, and 16% received prior IO treatment. Forty-six (58.2%) patients had treatment-related TEAEs; those occurring in ≥5% of patients are presented in Table 2. Ten patients (12.7%) had grade ≥3 treatment-related TEAEs. Immune-related TEAEs occurred in 15 patients (19.0%); the most common (>1 patient) included peripheral sensory neuropathy (n=5), pruritus (n=3), immune-mediated neuropathy (n=2), and peripheral motor neuropathy (n=2). In total, 10 (12.7%) patients had TEAEs of peripheral neuropathy; all were grade ≤3. All grade 2 or 3 TEAEs of peripheral neuropathy resolved or improved with either study drug continuation without dose modification, dose reduction, or drug interruption/discontinuation. Patients with TEAEs leading to treatment interruption were 21 (26.6%), dose reduction 5 (6.3%), and discontinuation 13 (16.5%). Five patients (6.3%) died of a TEAE (cerebrovascular accident, dyspnea, general physical health deterioration, intestinal obstruction, intracranial hemorrhage [each n=1]); all fatal TEAEs were considered unrelated to study drug. The efficacy-evaluable population included 68 patients; ORR was 11.8% (95%CI, 5.2%–21.9%; CR, 1.5%; PR, 10.3%), and DCR was 19.1% (95%CI, 10.6%–30.5%; Table 3). Eight objective responses were observed at doses ≥400 mg BID (Table 4); 3 of these were noted among the 5 IO treatment-naive patients with MSI-H tumors who received 400 mg BID.ConclusionsImmune-related AEs observed in this ongoing phase 1 study are consistent with those seen with antibody immune checkpoint inhibitors, with the exception of peripheral neuropathy. Preliminary efficacy of INCB086550 in tumor types known to be responsive to anti-PD-(L)1 therapy is encouraging and warrants further investigation.Trial RegistrationClinicaltrials.gov identifier NCT03762447ReferencesPiha-Paul S, et al. J Immunother Cancer. 2020;8(suppl 3):A255.Ethics ApprovalThe study protocol was approved by institutional review boards (IRB) or independent ethics committees at participating centers. All study participants gave informed consent before taking part. The approval numbers were: Integ Review IRB (Austin, TX), RM 598; MD Anderson Cancer Center Office of Human Subject Protection (Houston, TX), IRB ID 2018-0765; ADVARRA (Columbia, MD), IRB# 00000971; Ethisch Comité/Comité d’ Ethique Hospital (Brussels, Belgium), A2021/085; Hôpital Saint-Louis (Paris, France), Prof Le Tourneau – 2020-118/Ref. of the Promoter 0.09.22.72214; NHS Health Research Authority London - City & East Research Ethics Committee (Bristol, UK), IRAS project ID:282291/REC reference: 20/LO/1001; Comitato Etico IRCCS Pascale (Milan, Italy), ISS Validation Protocol Number 29111(2020)-PRE21-1835; Comitato Etico Della Fondazione IRCCS ”Istituto Nazionale Dei Tumori”- Milano CE150053 (Milan, Italy), INT 230/20; Comitato Etico Regione Toscana - Area Vasta Sud Est CE150047, 18064; Comitato Etico Indipendente Istituto Clinico Humanitas CE150081, 940/20; Regulatory Pharma Net (Pisa, Italy), IEC 1393.Abstract 529 Table 1Number of patients per dose levelBID, twice daily; QD, once daily.The tumor types in the study included breast, cervical, colorectal, endometrial, esophageal, gastric, hepatocellular, melanoma, mesothelioma, ovarian, small cell lung cancer, squamous cell carcinoma of the head and neck, renal cell, urothelial, adrenal, anal, cholangiocarcinoma, gall bladder, pancreatic, penile, salivary gland, sarcoma, vaginal, prostate, basal cell, pleomorphic sarcoma, fallopian, carcinoma of parotid gland, well-differentiated liposarcoma, myoepithelial, castrate-resistant prostate cancer, cancer of unknown primary, neuroendocrine, prostate adenocarcinoma with neuroendocrine differentiation, glioblastoma, anal canal, angiosarcoma, and gastroesophageal junction.Abstract 529 Table 2Treatment-related TEAEs reported by ≥5% of patients (N=79)TEAE, treatment-emergent adverse event.Abstract 529 Table 3Summary of best overall response by RECIST v1.1 or RANO*CR, complete response; DCR, disease control rate; GBM, glioblastoma; ORR, objective response rate; PR, partial response; RANO, Response Assessment of Neuro-Oncology; RECIST, Response Evaluation Criteria in Solid Tumors; SD, stable disease.* 1 patient with GBM was assessed by RANO and had best overall response of progressive disease.† The efficacy-evaluable population included all solid tumor participants enrolled in the study who received at least 1 dose of INCB086550, completed a baseline scan, and met at least 1 of the following criteria: ≥1 postbaseline scan, participant had been on the study for a minimum of 63 days of follow-up, or participant had discontinued from treatment.‡ ”Not evaluable” indicates participants in the efficacy-evaluable population that did not have valid postbaseline overall response assessments by RECIST or RANO.§ ”Not assessed” indicates participants in the efficacy-evaluable population that did not have any postbaseline overall response assessments by RECIST or RANO.Abstract 529 Table 4Tumor types with investigator-assessed objective response per RECIST v1.1 (n=8)BID, twice daily; dMMR, deficient mismatch repair; IO, immuno-oncology; MSI-H, high microsatellite instability; RECIST, Response Evaluation Criteria in Solid Tumors.+Ongoing response.

Purpose/Objective(s) Radiation therapy (RT) is a critical modality for the treatment of unresectable hepatocellular carcinoma (HCC). Little is known about how the etiology of HCC impacts overall and progression free survival (OS and PFS) in patients treated with definitive RT. We hypothesize that patients treated with definitive RT for HCC secondary to hepatitis B and hepatitis C viruses (viral group) would have favorable OS and PFS when compared to patients with HCC secondary to other etiologies (non-viral group). Materials/Methods Medical records were retrospectively reviewed at a single institution for patients diagnosed with unresectable HCC and treated with definitive RT between 1/2011 and 12/2020. Patients treated with prior surgery or radiofrequency ablation were excluded. Progress notes were reviewed to determine date of last follow-up, progression, and death. Notes were also assessed to determine the etiology of HCC, age at diagnosis, Child-Pugh classification (CPC), AJCC 8th edition T stage, RT strategy, and planning target volume (PTV). Descriptive statistics were quantified for baseline characteristics. Survival curves were estimated via Kaplan-Meier method; statistical difference was determined using the log-rank test. Multivariate (MVA) Cox proportional hazards analysis was conducted to estimate hazard ratios (HR) when controlling for confounding factors. Results Forty-six patients were included in the analysis. 30 (65%) patients were in the viral group, while 16 (35%) patients were in the non-viral group. Median ages at diagnosis for the viral and non-viral groups were 64 (interquartile range (IQR): 60 to 69) and 71 years (IQR: 66.5 to 76.5), respectively (P = 0.014). Treatment with hypofractionated RT (P = 0.559), proton therapy (P = 0.686), performance status (P = 0.222), CPC (P = 0.270), T stage (P = 0.639), and PTV (P = 0.472) were not different between groups. There was a trend toward improved Median OS for the viral group compared to the non-viral group: 17.9 months (95% confidence interval (CI): 9.7 to not-reached (NR)) vs. 8.8 months (95% CI: 6.1 to NR) (P = 0.072). Similarly, PFS was not different between viral and non-viral groups: 9.3 (95% CI: 7.4 to 19.0) vs. 8.0 (95% CI: 4.0 to 10.3), P = 0.314. However, after controlling for confounding factors with MVA Cox proportional hazards models, the viral group had superior OS (HR = 4.20, 95% CI: 1.47 to 12.02, P = 0.008); the viral group also had superior PFS (HR = 2.48, 95% CI: 1.06 to 5.81, P = 0.037). Conclusion Our retrospective review of patients with unresectable HCC treated with definitive RT provides evidence that viral etiologies of HCC may fare better in OS and PFS when compared to non-viral etiologies. The etiology of HCC development for virally vs non-virally mediated tumors may have implications for treatment and response in the setting of radiation therapy.

Background Expert knowledge is often shared among multidisciplinary academic teams at tumor boards (TBs) across the country, but these conversations exist in silos and do not reach the wider oncology community. Objective Using an oncologist-only question and answer (Q&A) website, we sought to document expert insights from TBs at National Cancer Institute–designated Comprehensive Cancer Centers (NCI-CCCs) to provide educational benefits to the oncology community. Methods We designed a process with the NCI-CCCs to document and share discussions from the TBs focused on areas of practice variation on theMednet, an interactive Q&A website of over 13,000 US oncologists. The faculty translated the TB discussions into concise, non–case-based Q&As on theMednet. Answers were peer reviewed and disseminated in email newsletters to registered oncologists. Reach and engagement were measured. Following each Q&A, a survey question asked how the TB Q&As impacted the readers’ practice. Results A total of 23 breast, thoracic, gastrointestinal, and genitourinary programs from 16 NCI-CCC sites participated. Between December 2016 and July 2021, the faculty highlighted 368 questions from their TBs. Q&As were viewed 147,661 times by 7381 oncologists at 3515 institutions from all 50 states. A total of 277 (75%) Q&As were viewed every month. Of the 1063 responses to a survey question on how the Q&A affected clinicians’ practices, 646 (61%) reported that it confirmed their current practice, 163 (20%) indicated that a Q&A would change their future practice, and 214 (15%) reported learning something new. Conclusions Through an online Q&A platform, academics at the NCI-CCCs share knowledge outside the walls of academia with oncologists across the United States. Access to up-to-date expert knowledge can reassure clinicians’ practices, significantly impact patient care in community practices, and be a source of new knowledge and education.

Introduction Hepatic artery infusion pump (HAIP) chemotherapy is a specialized therapy for patients with unresectable colorectal liver metastases (uCRLM). Its effectiveness was demonstrated from a high volume center, with uncertainty regarding the feasibility and safety at other centers. Therefore, we sought to assess the safety and feasibility of HAIP for the management of uCRLM at other centers. Methods We conducted a multicenter retrospective cohort study of patients with uCRLM treated with HAIP from January 2003 to December 2017 at six North American centers initiating the HAIP program. Outcomes included the safety and feasibility of HAIP chemotherapy. Results We identified 154 patients with HAIP insertion and the median age of 54 (48-61) years. The burden of disease was >10 intra-hepatic metastatic foci in 59 (38.3%) patients. Patients received at least one cycle of systemic chemotherapy before HAIP insertion. Major complications occurred in 7 (4.6%) patients during their hospitalization and 13 (8.4%) patients developed biliary sclerosis during follow-up. A total of 148 patients (96.1%) received at least one-dose of HAIP chemotherapy with a median of 5 (4-7) cycles. 78 patients (56.5%) had a complete or partial response and 12 (7.8%) received a curative liver resection. Conclusion HAIP programs can be safely and effectively initiated in previously inexperienced centers with good response.

Locally advanced rectal cancer has broadly been defined as T3, T4, or lymph node-positive disease. In the 1990s, adjuvant chemoradiation was considered the optimal management for locally advanced rectal cancer. However, the paradigm shifted when the German CAO/ARO/AIO-94 Rectal Cancer trial established neoadjuvant chemoradiation as the standard of care, based on reduced rates of toxicity and local recurrence, as well as higher rates of sphincter preservation compared with postoperative chemoradiation. Both short-course radiation and long-course chemoradiation are currently accepted methods for neoadjuvant treatment, with recent trials showing equivalence in outcomes. While surgery remains the cornerstone of treatment, there are data supporting the use of magnetic resonance imaging for risk stratification in rectal cancer and encouraging prospective data regarding nonoperative management. This review summarizes data on the evolution of treatment for locally advanced rectal cancer and discusses emerging evidence for nonoperative management.

PURPOSE/OBJECTIVE(S) Neoadjuvant chemoradiotherapy is a critical treatment for borderline resectable and resectable pancreatic adenocarcinoma ((B)RPC). The PREOPANC trials employ a short course chemoradiation (SCCRT) regimen of 3600 cGy in 15 fractions with concurrent gemcitabine (GEM)-based chemotherapy, but little is known about the relative efficacy of capecitabine (CAPE)-based concurrent chemotherapy in this population. We hypothesize that patients treated with SCCRT with CAPE-based concurrent chemotherapy will have superior overall survival (OS) compared to GEM-based strategies. MATERIALS/METHODS Medical records were retrospectively reviewed at a single center for patients diagnosed with (B)RPC between 1/2005 and 12/2020. Patients treated with neoadjuvant SCCRT were included in the analysis. Descriptive statistics were quantified for baseline characteristics. OS was estimated using Kaplan-Meier estimates, statistical difference was determined using the log-rank test. Multivariate Cox proportional hazards analysis was conducted to estimate hazard ratios (HR) when controlling for confounding factors. RESULTS Thirty-one (n = 31) patients were included in the analysis. 71% of patients (n = 22) were treated with CAPE-based concurrent chemotherapy, while 29% of patients (n = 9) were treated with GEM-based concurrent chemotherapy. Median age at diagnosis was 65 (interquartile range (IQR): 60 to 71) for the CAPE group, compared to 66 (IQR: 63 to 71) for the GEM group, P = 0.414. 100% of patients in the CAPE group were borderline resectable, compared to 82% of patients in the GEM group, P = 0.171. 44% of patients in the CAPE group were treated with neoadjuvant FOLFIRINOX, compared to 14% in the GEM group, P = 0.016. Patients treated with concurrent 5-CAPE-based chemotherapy had a longer median OS than other concurrent chemotherapy approaches: Not reached (95% confidence interval (CI): 24 to not reached) vs. 17 months (95% CI: 6 to 22 months), P < 0.0001. Multivariate Cox proportional hazards models, controlling for borderline vs. resectable status, age at diagnosis, and use of neoadjuvant FOLFIRINOX, demonstrated that CAPE-based concurrent chemotherapy had a HR of death of 0.081 (95% CI: 0.018 to 0.369, P = 0.0012) compared to GEM-based concurrent chemotherapy. CONCLUSION Patients diagnosed with (B)RPC have many therapeutic options; this study suggests a benefit to CAPE-based concurrent chemotherapy when treating patients with SCCRT, even after controlling for significant confounding by greater use of neoadjuvant FOLFIRINOX with CAPE-based concurrent chemotherapy. SCCRT may be more effective with concurrent capecitabine instead of concurrent gemcitabine for (B)RPC.

Purpose/Objective(s) Radiation therapy (RT) remains a critical treatment modality for unresectable hepatocellular carcinoma (HCC), with proton beam therapy (PBT) being widely utilized due to its decreased exit dose compared to photon-based RT. We hypothesize that patients with HCC receiving definitive PBT would experience decreased acute toxicity when compared to those receiving photon-based RT. Materials/Methods Electronic medical records were retrospectively reviewed at a single institution for patients diagnosed with unresectable HCC and treated with definitive RT between 1/2011 and 12/2020. Patients treated with prior surgery or radiofrequency ablation were excluded. Progress notes and treatment summaries were reviewed to determine baseline characteristics including age at diagnosis, Child-Pugh classification (CPC), AJCC 8th edition T stage, performance status, and RT dose. Acute treatment toxicities were evaluated using Common Terminology Criteria for Adverse Events v5.0. Descriptive statistics were quantified for baseline characteristics. Odds ratios (OR) with 95% confidence intervals (CI) were generated to determine the association between PBT vs. photon therapy and acute radiation toxicities in bivariate and multivariate logistic regression models. Results Forty-six patients were included in the analysis. 24 (52%) patients received PBT while 22 (48%) received photon-based RT. Median age for the PBT and photon-based RT groups were 67 (interquartile range (IQR): 58.6 to 72.5) and 65.5 years (IQR: 61.0 to 73.0), respectively (P = 0.991). 50% of patients who received PBT had a T stage greater than T2, compared to 71% of patient in the photon group (P = 0.148). 42% of the PBT group had CPC B or worse, compared to 38% in the photon group (P = 0.813). Performance status and total dose did not significantly differ between groups (P = 0.351 and P = 0.773, respectively). PBT was associated with higher odds of any grade radiation dermatitis (RD) (OR = 6.00, 95% CI: 1.13 to 31.9) and lower odds of any grade anorexia (OR = 0.21, 95% CI 0.05 to 0.91). Odds of any grade diarrhea and fatigue, did not significantly differ between groups (P = 0.086 and P = 0.958, respectively). After controlling for performance status, total dose, T stage, CPC, and age at diagnosis, PBT was still associated with higher odds of RD (OR = 11.07, 95% CI: 1.14 to 107.71) and lower odds of anorexia (OR = 0.14, 95% CI: 0.02 to 0.93). Conclusion This study provides evidence that although PBT appears to have a superior safety profile in regard to acute anorexia, patients treated with PBT have higher odds of acute RD; these effects persist even after controlling for relevant confounding factors. PBT may result in fewer GI toxicities at the cost of greater skin toxicity.

Objectives The survival of patients with metastatic colorectal cancer (CRC) has been increasing over recent decades due to improvements in chemotherapy and surgery. There is a need to refine prognostic information to more accurately predict survival as patients survive for any given length of time to assist multidisciplinary cancer management teams in treatment decisions. Materials and methods We performed a single center retrospective analysis of patients treated with metastatic CRC (unresectable and resectable) who survived >24 months between 2005 and 2015 (N=155). Patient tumor and treatment related variables were collected. Overall survival (OS) estimates conditional on surviving >24 months were compared with actuarial survival estimates of a cohort of patients (33,104 resected, 39,382 unresected) from the National Cancer Database (NCDB). Results With a median follow-up of 44.2 months, the median OS of resected patients (n=86) was not reached. The median OS of unresected patients was 75.9 months. The conditional survival probabilities of living 1, 2, or 3 years longer after 24 months of survival are 92%, 72%, and 52%, respectively, in unresectable patients and 98%, 92%, and 89% in patients who were resected. The corresponding NCDB 1, 2, and 3 year actuarial survival was 38%, 20%, and 11% for unresected patients and 68%, 46%, and 32% for resected. Conclusions These results indicate that CRC patients who survive 24 months with metastatic colorectal cancer have an excellent prognosis and surgery may be appropriate in a subset of patients initially deemed unresectable.

Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide, with a majority of HCC patients not suitable for curative therapies. Approximately 70% of initially diagnosed patients cannot undergo surgical resection or transplantation due to locally advanced disease, poor liver function/underlying cirrhosis, or additional comorbidities. Local therapeutic options for patients with unresectable HCC, who are not suitable for thermal ablation, include transarterial embolization (bland, chemoembolization, radioembolization) and/or external beam radiation therapy (EBRT). Regarding EBRT specifically, technological advancements provide a means for safe and effective radiotherapy delivery in a wide spectrum of HCC patients. In multiple prospective studies, EBRT delivery in a variety of different fractionation schemes or in combination with transcatheter arterial chemoembolization (TACE) demonstrate improved outcomes, particularly with combination therapy. The Barcelona Clinic Liver Cancer classification provides a framework for treatment selection; however, given the growing complexity of treatment strategies, this classification system tends to simplify decision-making. In this review, we discuss the current literature regarding unresectable HCC and propose a modified treatment algorithm that emphasizes the role of radiation therapy for Child-Pugh score A or B patients with ≤3 nodules measuring >3 cm, multinodular disease or portal venous thrombosis.

Of all patients diagnosed with pancreatic adenocarcinoma, only 15–20% present with resectable disease. Despite curative-intent resection, the prognosis remains poor with the majority of patients recurring, prompting the need for adjuvant therapy. Historical data support the use of adjuvant 5-fluorouracil (5-FU) or gemcitabine, but recent data suggest either gemcitabine plus capecitabine or modified FOLFIRINOX can improve overall survival when compared to gemcitabine alone. The use of adjuvant chemoradiation therapy remains controversial, primarily due to limitations in study design and mixed results of historical trials. The ongoing Radiation Therapy Oncology Group (RTOG)-0848 trial hopes to further define the role of adjuvant chemoradiation therapy. Intraoperative radiation therapy (IORT) and adjuvant immunotherapy represent additional possibilities to improve outcomes, but evidence supporting their use is limited. This article reviews adjuvant therapeutic strategies for resectable pancreatic adenocarcinoma, including chemotherapy, chemoradiation therapy, IORT and immunotherapy.

Prior studies examining the risk of second primary malignancy (SPM) after a first primary cancer generally have used large datasets such as the Surveillance, Epidemiology, and End Results (SEER) registry and excluded survivors of previous primaries and developers of synchronous primaries. The goal of this study was to provide a more complete representation of multiple cancer risk in squamous cell carcinoma of the anus (SCCA) patients. A single-institution retrospective study of 46 patients treated definitively for SCCA between January 2006 and July 2017 was conducted. Of the 46 patients, 18 (39%) had either a primary malignancy before SCCA (n=9) or SPM after an index SCCA (n=9). Six patients had ≥3 total malignancies. In our cohort, patients without SPMs tended to die from SCCA recurrence, while patients with SPMs were more likely to die from their SPM than from SCCA. Our study suggests that patients with SCCA are often either survivors of previous cancers or develop later malignancies. Several risk factors may play a role including HPV infection, HPV-related or treatment-related immunosuppression, somatic mutations due to chemotherapy, and genetic factors. Patients with SCCA require lifelong surveillance given their elevated risk of malignancy. Future work should focus on identifying genomic or immunologic factors that may predispose SCCA patients to develop multiple primary malignancies.

4064 Background: E/GEJ adenocarcinoma has a high mortality rate despite curative intent therapy. The use of immune checkpoint inhibition is beneficial for treatment of this cancer in the metastatic and adjuvant settings but the role of these agents in the perioperative setting remains unclear. Here we report the results of an initial safety run-in of nivolumab when given in combination with neoadjuvant chemoradiation. Methods: Pts with a localized T1N1-3M0 or T2-3N0-2M0 E/GEJ adenocarcinoma with an ECOG PS of 0-1 and whom were deemed surgical candidates for an esophagectomy by a qualified surgeon were eligible. In step 1, pts were randomized to neoadjuvant therapy with carboplatin AUC 2 and paclitaxel 50 mg/m2 intravenously (IV) weekly x 5 along with 41.4-50.4 Gy radiation without (Arm A) or with (Arm B) nivolumab 240 mg IV during weeks 1 and 3 of treatment, followed by esophagectomy. Pts underwent a second randomization (step 2) to adjuvant nivolumab 240 mg IV every 2 weeks x 12 cycles with or without ipilimumab 1 mg/kg IV every 6 weeks during cycles 1, 4, 7 and 10. For the safety run-in, 30 pts were planned for accrual to allow for 12 evaluable pts per arm. Pts were followed for safety during neoadjuvant therapy through surgery and toxicities monitored per CTCAEv5. Pre-specified early stopping rules were defined to allow halting of the trial if deemed unsafe. Planned study accrual is 278 pts. Neoadjuvant primary endpoint is pathologic complete response rate, adjuvant primary endpoint is disease-free survival. Results: A total of 31 pts were enrolled to the safety run-in element of the study (Arm A, n = 16; Arm B n = 15). Male, 94%; White, 100%; median age, 62; esophageal adenocarcinoma, 52%; GEJ, 48%. Grade (G) 3 events occurring in more than one pt on Arm A—decreased lymphocytes (n = 5). G4 events occurring on Arm A—decreased lymphocytes (n = 1). G3 events occurring in more than one pt on Arm B—decreased lymphocytes (n = 2); anemia (n = 2); leukopenia (n = 4); hypotension (n = 2). G4 events occurring on Arm B—decreased lymphocytes (n = 3); cardiac tamponade and pericardial effusion (n = 1). Cardiac events were thought to be secondary to tumor location, not neoadjuvant treatment. On Arm B, notable G3 events seen in one pt each included colonic obstruction, wound infection and esophageal anastomotic leak. Of pts who have reached the time for surgery, 12/14 pts on Arm A and 13/13 pts on Arm B have proceeded to surgery. Of pts who have completed step 1, 7/14 pts on Arm A and 8/11 pts on Arm B have registered to step 2. Conclusions: The addition of nivolumab to carboplatin, paclitaxel and radiation in the neoadjuvant setting appears to be safe with no disproportionate level of toxicity observed between the two treatment arms. Accrual to the remainder of the trial continues with 43/278 patients accrued. Clinical trial information: NCT03604991.

Background: BTCs are aggressive cancers with a poor prognosis. In preclinical models, MEK inhibition modulates the tumor immune microenvironment and enhances responses to programmed death-ligand 1 (PD-L1) inhibition. We report a randomized, open-label, multicenter phase 2 trial of atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor) in BTC (NCT03201458). Methods: Eligible patients had advanced BTC [intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (ECC), and gallbladder cancer (GBC)], with 1-2 lines of prior therapy in the metastatic setting, measurable disease by RECIST v1.1, and ECOG performance status ≤1. Patients randomized to Arm A received atezolizumab 840 mg IV Q2w. Patients randomized to Arm B received oral cobimetinib 60 mg daily (21 days on/7 days off) plus atezolizumab 840 mg IV Q2w. The primary endpoint was progression free survival (PFS) using the Kaplan-Meier method and compared between groups under the assumption of Cox proportional hazards, stratified for primary tumor site. Secondary endpoints included objective response rate (ORR), safety and tolerability, and overall survival (OS). Results: 86 patients were enrolled at 23 centers in the United States; 77 patients were randomized and received at least one dose of study therapy (Arm A: n=37, ICC=21, ECC=7, GBC=11; Arm B: n=38, ICC=22, ECC=8, GBC=8). Median age was 63 (range 44-86), and 48 (62%) were female. The trial met its primary endpoint, with a median PFS of 3.65 months (cobimetinib+atezolizumab) vs 1.87 months (atezolizumab monotherapy) (p=0.027). OS data are not mature at the time of analysis. There was 1 PR (3.2%), 13 SD (41.9%), and 17 PD (54.8%) in the combination arm and 1 PR (2.9%), 10 SD (29.4%), and 23 PD (67.6%) in the atezolizumab monotherapy arm. Two patients in the combination arm remain on therapy 15+ months from enrollment. One patient in each treatment arm had known mismatch repair deficiency (MMRd), of whom 1 had PD as a best response and the other withdrew prior to response evaluation. Grade 3-4 treatment-related adverse events were similar in both arms, and there were no treatment-related deaths. 4 (10%) of patients receiving atezolizumab monotherapy and 8 (22.2%) receiving cobimetinib+atezolizumab discontinued therapy due to adverse events. Changes in tumor CD8, CD4, FoxP3, PDL1, and MHC expression from paired tumor biopsies will be presented at the conference. Conclusions: We report the first randomized trial of immunotherapy in BTC. The combination of atezolizumab plus cobimetinib met its primary endpoint and significantly prolonged PFS as compared to atezolizumab monotherapy in BTC. The combination of atezolizumab and cobimetinib had manageable toxicity and warrants further investigation in BTC. Citation Format: Mark Yarchoan, Leslie Cope, Robert A. Anders, Anne Noonan, Laura W. Goff, Lipika Goyal, Jill Lacy, Daneng Li, Anuj Patel, Aiwu R. He, Ghassan Abou-Alfa, Kristen Spencer, Edward Kim, Stephanie Xavier, Amanda Ruggieri, S. Lindsey Davis, Autumn McRee, Paul Kunk, Qingfeng Zhu, Andrea Wang-Gillam, Andrew Poklepovic, Helen Chen, Elad Sharon, Gregory B. Lesinski, Nilo Azad. A multicenter randomized phase 2 trial of atezolizumab as monotherapy or in combination with cobimetinib in biliary tract cancers (BTCs): A NCI Experimental Therapeutics Clinical Trials Network (ETCTN) study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT043.

4020 Background: Patients (pts) with anal squamous cell carcinoma (ASCC) have poor outcomes and few treatment options. We report a pooled analysis of pembrolizumab (pembro) antitumor activity and safety in the ASCC cohorts of the multicohort studies KEYNOTE-028 (NCT02054806; phase 1b) and KEYNOTE-158 (NCT02628067; phase 2), providing a robust sample size and longer follow-up. Methods: Eligible pts were aged ≥18 y with histologically/cytologically confirmed metastatic/unresectable ASCC, had prior failure of/intolerance to standard therapy or no standard therapy options, measurable disease (RECIST v1.1), ECOG PS 0/1, and a tissue sample evaluable for PD-L1/biomarkers (KEYNOTE-028 required PD-L1 positivity). Baseline PD-L1 expression was assessed using a prototype IHC assay (QualTek) in KEYNOTE-028 and the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies) in KEYNOTE-158. Pts received pembro 10 mg/kg Q2W (KEYNOTE-028) or 200 mg Q3W (KEYNOTE-158) for 2 y or until PD/unacceptable AEs. The primary endpoint in both studies was ORR (per RECIST v1.1). Secondary endpoints were duration of response (DOR), PFS, OS, and safety. Results: 137 pts with ASCC were treated in KEYNOTE-028 (n = 25) or KEYNOTE-158 (n = 112) and were included in this analysis (median age, 61 y; 83.2% women; 73.0% had PD-L1–positive tumors). Median follow-up was 11.7 mo; 124 pts (90.5%) had discontinued treatment. ORR (95% CI) was 10.9% (6.3%–17.4%). 8 pts had CR and 7 had PR. ORR (95% CI) by PD-L1 status was 14.0% (7.9%–22.4%) in the PD-L1 positive group and 3.3% (0.1%–17.2%) in the PD-L1 negative group. Among all treated pts, median DOR was not reached (range, 6.0+ to 57.5+ mo). By Kaplan-Meier estimation, 84.6% of responders had a DOR ≥24 mo. Median PFS was 2.1 mo (95% CI, 2.0–2.1) and median OS was 11.7 mo (95% CI, 8.8–14.5). The 12-mo PFS and OS rates were 14.5% and 47.4%. 85 pts (62.0%) had +1 treatment-related AE, 24 pts (17.5%) with grade 3–4 events (no grade 5 events). 32 pts (23.4%) had immune-mediated AEs; 2 pts (1.5%) had infusion related reactions. Conclusions: In pts with previously treated advanced ASCC, pembro showed durable antitumor activity, particularly in pts with PD-L1–positive tumors, and manageable toxicity. Clinical trial information: NCT02054806 (KEYNOTE-028), NCT02628067 (KEYNOTE-158) .

TPS4651 Background: E/GEJ adenocarcinoma has a high mortality rate despite curative intent treatment. A pathologic complete response (pCR) is associated with better overall survival (OS) but occurs in less than 30% of pts. Immunotherapy is effective in the metastatic setting. Here we aim to evaluate the contribution of immunotherapy in the neoadjuvant and adjuvant settings in pts with locoregional E/GEJ cancer. Methods: This is a multi-center, randomized phase II/III trial. Surgical candidates with locoregional E/GEJ adenocarcinoma receive carboplatin AUC 2 IV and paclitaxel 50 mg/m2 IV, both weekly x 5 during concurrent radiation (50.4 Gy) either with or without nivolumab 240 mg IV during weeks 1 and 3, followed by surgery. Pts with no post-operative disease receive nivolumab 240 mg IV every 2 weeks for 12 cycles either with or without ipilimumab 1 mg/kg IV every 6 weeks for 4 cycles. Eligibility criteria include pts with T1-N1-3M0 or T2-3N0-2M0 disease whom are candidates for surgery, no prior chemotherapy or radiation for this disease, no prior immunotherapy, no significant autoimmune disease. Pts must be disease free for adjuvant treatment. Primary neoadjuvant endpoint is pCR rate; primary adjuvant endpoint is disease free survival (DFS). Secondary endpoints include toxicity, DFS and OS. Pre- and mid-treatment diffusion weighted imaging MRI will be conducted during the neoadjuvant portion of the study. A neoadjuvant safety run in of 30 pts is underway. Overall, 278 pts will be needed to detect an absolute improvement of 15% in pCR rate in pts receiving and not receiving neoadjuvant nivolumab and 236 pts will be needed to detect a HR of 0.65 in favor of adjuvant ipilimumab/nivolumab over nivolumab (90% power, one sided alpha of 0.10). Accrual is expected over 34 months at a rate of 8 patients per month. If favorable at interim analysis. Clinical trial information: NCT03604991 .

79 Background: The Metabotropic Glutamate Receptor 1 (GRM1) is overexpressed in many solid tumors. It activates MAPK and PI3K/AKT pathways and promotes an immune-suppressive tumor microenvironment. In an immunocompetent melanoma mouse model, GRM1 blockade using riluzole or its pro-drug troriluzole (BHV-4157) and PD-1 blockade inhibit tumor growth in an additive manner. We conducted a phase Ib trial of troriluzole and the PD-1 antibody nivolumab. Methods: Patients with advanced or refractory solid tumors were treated with increasing doses of troriluzole. Troriluzole monotherapy was given for a 14-day lead-in period and then patients received troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Results: We enrolled 14 patients with advanced solid tumors (melanoma=3, NSCLC=3, renal cell cancer=2, NSCLC=2, head and neck cancer=2). Eleven patients had prior therapy with anti-PD-(L)1. PK sampling demonstrated that the prodrug was cleaved efficiently without regard to food (Table). The most common TEAEs (all grades) occurring in >40% of patients were transaminitis, increased lipase and nausea. DLT occurred in 3 patients: 1) grade 3 anorexia, 2) grade 3 fatigue and, 3) atrial fibrillation. The MTD was determined to be troriluzole 140 mg QAM + 280 mg PO QHS. The response rate was 7 % (1/14); this occurred in a PD-L1 treated patient. The 6-month PFS rate was 21%. Correlative studies will be presented. Conclusions: The combination of troriluzole and nivolumab was safe and well-tolerated in this highly PD-1 refractory population. Clinical trial information: NCT03229278. [Table: see text]

1 Background: For patients (pts) with ASCC, second-line or later treatment options have been limited. Pembrolizumab (pembro), an anti-PD-1 monoclonal antibody, has demonstrated antitumor activity in several tumor types (including ASCC) in the multicohort phase 1b KEYNOTE-028 study. KEYNOTE-158 (NCT02628067) is an open-label, phase 2, multicohort study that evaluates antitumor activity and safety of pembro in pts with previously treated advanced cancer. Results from the ASCC cohort are presented. Methods: Eligible pts were ≥18 y with histologically/cytologically documented metastatic and/or unresectable ASCC with prior treatment failure on or intolerance to standard first-line therapy, measurable disease per RECIST v1.1, ECOG PS of ≤1, and evaluable tissue sample for PD-L1 and biomarker analysis. PD-L1 expression was assessed by the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies). Pts received pembro 200 mg Q3W until disease progression, unacceptable AE, or completion of 35 cycles. The primary endpoint was ORR per RECIST v1.1 (assessed every 9 wk for 12 mo, then every 12 wk thereafter) by independent central review. Secondary endpoints were DOR, OS, PFS and safety. Results: 112 pts with ASCC were enrolled (81.3% women; median age, 61 y [range 32–79]; ≥2 prior therapies, 73.2%). At database cutoff (Dec 6, 2018) 10 pts (8.9%) had completed 35 cycles and 102 discontinued; median follow-up was 12.0 mo (range, 0.8–33.0) Five pts had CR and 8 had PR; ORR was 11.6% (95% CI, 6.3–19.0). Median DOR was not reached (range, 6.0+ to 29.1+ mo). Responses occurred in 11/75 pts (14.7%) with PD-L1 combined positive score (CPS) ≥1 and 2/30 pts (6.7%) with PD-L1 CPS < 1. Among all pts, median OS was 12.0 mo (95% CI, 9.1–15.4), and median PFS was 2.0 mo (95% CI, 2.0–2.1). 68 (60.7%) pts had treatment-related AEs, including 21 (18.8%) who had grade 3–5 events; there were no treatment-related deaths. 4 pts (3.6%) discontinued due to treatment-related AEs. 27 pts (24.1%) had immune-mediated AEs/infusion reactions. Conclusions: Pembro demonstrated antitumor activity and manageable toxicity in pts with heavily pretreated advanced ASCC, regardless of PD-L1 status. Clinical trial information: NCT02628067.

Locally advanced rectal cancer has broadly been defined as T3, T4, or lymph node-positive disease. In the 1990s, adjuvant chemoradiation was considered the optimal management for locally advanced rectal cancer. However, the paradigm shifted when the German CAO/ARO/AIO-94 Rectal Cancer trial established neoadjuvant chemoradiation as the standard of care, based on reduced rates of toxicity and local recurrence, as well as higher rates of sphincter preservation compared with postoperative chemoradiation. Both short-course radiation and long-course chemoradiation are currently accepted methods for neoadjuvant treatment, with recent trials showing equivalence in outcomes. While surgery remains the cornerstone of treatment, there are data supporting the use of magnetic resonance imaging for risk stratification in rectal cancer and encouraging prospective data regarding nonoperative management. This review summarizes data on the evolution of treatment for locally advanced rectal cancer and discusses emerging evidence for nonoperative management.

Liver cancer is the sixth most common cancer and the second leading cause of death worldwide. Only 30–40% of patients are candidates for curative intervention at the time of diagnosis, and up to 70% of those who undergo curative resection will recur. Cytotoxic chemotherapy in advanced disease is not effective and is often limited by concomitant hepatic dysfunction. Sorafenib, a multiple kinase inhibitor, is the only therapy to have shown an overall survival benefit that is only modest at best. Thus, there is a large unmet need to develop additional therapies. In recent years, a diverse array of phenotypic and genetic alterations have been identified in HCC patients. Following these advances, several phase III studies with therapies targeted toward these alterations have been conducted; however, none has shown a survival benefit. It remains to be seen if this new understanding in these alterations can be translated therapeutically. In this chapter, we will discuss these alterations, as well as the developing therapies targeting them.

TPS478 Background: C is an inhibitor of tyrosine kinases involved in tumor growth, angiogenesis, and immune regulation, including MET, VEGFR, and TAM family kinases (Tyro3, AXL, MER). Preclinical and clinical studies suggest that C promotes an immune-permissive tumor environment which may enhance response to checkpoint inhibitors such as the anti-PD-L1 mAb A. C significantly improved overall survival vs placebo in previously treated advanced HCC, and the combination of A and bevacizumab has shown synergistic activity in advanced HCC. Checkpoint inhibitors have shown clinical activity in advanced CRC primarily in pts with high microsatellite instability (MSI); combination with immune-modulating agents may enhance activity in pts with stable or low MSI. Likewise, combination therapy may improve response in pts with GC/GEJC resistant to standard chemotherapy. Here, we present the study design of an ongoing phase 1b trial which includes cohorts with advanced HCC, GC/GEJC, or CRC. Methods: This global, phase 1b, open-label trial will assess the safety, tolerability, preliminary efficacy, and pharmacokinetics of C in combination with A (NCT03170960). The study consists of a dose-escalation stage and an expansion stage. In the dose-escalation stage (3+3 design), a recommended C dose for combination with a standard dose of A will be established. In the expansion stage, 18 cohorts will be enrolled at the recommended dose of C + A including 3 cohorts with gastrointestinal cancers: (1) advanced HCC not previously treated with systemic therapy; (2) advanced GC/GEJC after progression on platinum- or fluoropyrimidine-containing therapy; and (3) advanced CRC after progression on fluoropyrimidine combined with oxaliplatin or irinotecan. Pts will continue treatment as long as they experience clinical benefit as judged by the investigator or until unacceptable toxicity. The primary objective of the expansion stage is the objective response rate for each cohort. Exploratory objectives include correlation of tumor and plasma biomarkers, immune cell profiles, and MSI status with clinical outcome. Clinical trial information: NCT03170960.

Lymphangiomatosis, a rare disorder of the lymphatic system characterized by the abnormal proliferation of lymphatic vessels, is a typically benign disorder that at times can exhibit invasive or malignant behavior. While generally considered a diagnosis of childhood, in adults the majority of cases are asymptomatic and found incidentally. Rarely, lymphatic overgrowth can occur, causing growth of lesions on imaging mimicking a metastatic process and occasionally, resulting in substantial morbidity and mortality. Here, we present such a case of lymphangiomatosis with multi-organ system involvement in liver, bone, and spleen. In addition to details of the clinical presentation and the pathologic review which led to the diagnosis, we describe our use of the tyrosine kinase inhibitor pazopanib, which may cause stabilization of lymphangiomatosis through blockade of vascular endothelial growth factor (VEGF) signaling, for systemic treatment in this unusual case.

Immunotherapy has revolutionized cancer therapy and has been named the cancer advance of the year for 2016. Checkpoint inhibitors have demonstrated unprecedented rates of durable responses in some of the most difficult-to-treat cancers; however, many treated patients do not respond, and the potential for serious side effects exists. There is a growing need to identify biomarkers that will improve the selection of patients who will best respond to therapy, further elucidate drug mechanisms of action, and help tailor therapy regimens. Biomarkers are being explored at the soluble, cellular, and genomic levels, and examples in immunotherapy include serum proteins, tumor-specific receptor expression patterns, factors in the tumor microenvironment, circulating immune and tumor cells, and host genomic factors. The search for reliable biomarkers is limited by our incomplete understanding of how immunotherapies modify the already complex immune response to cancer, as well as the contribution of immuno-editing to a dynamic and inducible tumor microenvironment and immune milieu. Furthermore, there has been little extension of any candidate assay into large, prospective studies, and the lack of standardization in measurement and interpretation restricts their validity. Both tumor-infiltrating lymphocytes and PD-L1 expression within the tumor microenvironment have been recognized as having both prognostic and predictive value for patients treated with immunotherapy. Alternately, a larger panel of gene signatures, chemokines, and other factors that correlate with response has been proposed. In this article, we will explore the status of current biomarker candidates.

Mucosal melanoma is an exceedingly rare variant of cutaneous melanoma that, due to its rarity, is poorly described and infrequently studied. Primary sites of origin include the head and neck, anorectum and vulvovaginal regions. It is uniquely different from cutaneous melanoma with respect to epidemiology, etiology, pathogenesis and prognosis. The etiology and pathogenesis remain unclear. Unlike cutaneous melanoma, exposure to UV light is not an apparent risk factor. Furthermore, distinct molecular features including a lower incidence of BRAF oncogene mutations but a higher incidence of KIT oncogene mutations suggest divergent genetic etiologies. Mucosal melanomas generally present at a later stage, are more aggressive and carry a worse prognosis regardless of the stage at diagnosis. Establishing standardized treatment guidelines has been challenging due to the rarity of the disease. Early detection provides the best chance at survival but is often difficult due to anatomic location. Surgery remains the primary therapeutic intervention if complete resection is technically feasible given the anatomic location. Radiotherapy may be used to achieve local control when resection is not feasible, or adjuvantly to enhance locoregional control, but most studies have failed to demonstrate an improvement in overall survival. There are no consensus guidelines on the optimal systemic therapy, and regimens are often extrapolated from data based on therapies used to treat advanced cutaneous melanoma. Clinical trials, particularly utilizing newer targeted therapies and immunotherapies, are investigating novel treatment approaches.

Ipilimumab is a fully human, monoclonal antibody directed against Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) that has demonstrated a survival benefit and durable disease control in patients with advanced melanoma. Ipilimumab is associated with potentially serious immune-related adverse events, including autoimmune hepatitis. Because clinical trials of ipilimumab excluded patients with pre-existing hepatitis B or C infection, there is a paucity of data on the safety of ipilimumab administration to that patient population. Here, we report the largest case series to date of patients with hepatitis B or C who received ipilimumab for advanced melanoma. Two of the nine patients described in this case series experienced fluctuations in their liver function tests (LFTs) and were subsequently treated with corticosteroids. Although this is a small series, the rate of hepatotoxicity appears similar to what has been seen in the general population treated with ipilimumab, and the ability to administer ipilimumab did not appear to be affected by concomitant hepatitis B or C infection. The use of ipilimumab in patients with metastatic melanoma who have pre-existing hepatitis can be considered among other therapeutic options.

Importance Ipilimumab and other immune therapies are effective treatment options for patients with advanced melanoma but cause frequent immune-related toxic effects. Autoimmune diseases are common, and the safety and efficacy of ipilimumab therapy in patients with preexisting autoimmune disorders is not known. Objective To determine the safety and efficacy of ipilimumab therapy in patients with advanced melanoma with preexisting autoimmune disorders. Design, Setting, and Participants Retrospective review of patients with advanced melanoma and preexisting autoimmune disorders who received ipilimumab at 9 academic tertiary referral centers from January 1, 2012, through August 1, 2015. The data analysis was performed on August 24, 2015. Exposure Ipilimumab therapy. Main Outcomes and Measures Safety, in terms of frequency of autoimmune flares and conventional immune-related adverse events (irAEs), and efficacy, in terms of response rates and overall survival, were evaluated descriptively. Results Of the 30 patients who received ipilimumab (17 [57%] male; median [range] age, 59.5 [30-80] y), 6 had rheumatoid arthritis, 5 had psoriasis, 6 had inflammatory bowel disease, 2 had systemic lupus erythematosus, 2 had multiple sclerosis, 2 had autoimmune thyroiditis, and 7 had other conditions. Thirteen patients (43%) were receiving immunosuppressive therapy at the time of initiation of ipilimumab therapy, most commonly low-dose prednisone or hydroxychloroquine. With ipilimumab treatment, 8 patients (27%) experienced exacerbations of their autoimmune condition necessitating systemic treatment; all were managed with corticosteroids. Conventional grade 3 to 5 irAEs occurred in 10 patients (33%) and were reversible with corticosteroids or with infliximab therapy in 2 cases. One patient with baseline psoriasis died of presumed immune-related colitis after a 1-week delay prior to reporting symptoms. Fifteen patients (50%) had neither autoimmune disease flares nor irAEs. Six patients experienced an objective response (20%), including 1 with a durable complete response. Conclusions and Relevance To our knowledge, this is the largest series of patients with preexisting autoimmune disease treated with immune checkpoint inhibitors. Ipilimumab was clinically active and was associated with exacerbations of autoimmune disease and conventional ipilimumab-induced irAEs that were readily manageable with standard therapies when started in a timely fashion. Ipilimumab therapy may be considered in this setting with vigilant clinical monitoring.

11086 Background: Metabotropic glutamate receptor 1 (GRM1) activates MAPK and PI3K/AKT signaling and is implicated in multiple cancers including breast, prostate and melanoma. GRM1 overexpression s...

TPS9092 Background: The incidence of SCCS has increased over the past two decades, including a high risk subset with aggressive behavior. Due to a lack of high-quality clinical trials in this popul...