Susanna Varkey Ulahannan

Tremelimumab in combination with ablation in patients with advanced hepatocellular carcinoma

BACKGROUND & AIMS Tremelimumab is a fully human monoclonal antibody that binds to cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on the surface of activated T lymphocytes. Ablative therapies induce a peripheral immune response which may enhance the effect of anti-CTLA4 treatment in patients with advanced hepatocellular carcinoma (HCC). This study aimed to demonstrate whether tremelimumab could be combined safely and feasibly with ablation. METHODS Thirty-two patients with HCC were enrolled: male:female: 28:4; median age: 62 (range 36-76). Patients were given tremelimumab at two dose levels (3.5 and 10mg/kg i.v.) every 4weeks for 6 doses, followed by 3-monthly infusions until off-treatment criteria were met. On day 36, patients underwent subtotal radiofrequency ablation or chemoablation. Staging was performed by contrast-enhanced CT or MRI scan every 8weeks. RESULTS No dose-limiting toxicities were encountered. The most common toxicity was pruritus. Of the 19 evaluable patients, five (26.3%; 95% CI: 9.1-51.2%) achieved a confirmed partial response. Twelve of 14 patients with quantifiable HCV experienced a marked reduction in viral load. Six-week tumor biopsies showed a clear increase in CD8+ T cells in patients showing a clinical benefit only. Six and 12-month probabilities of tumor progression free survival for this refractory HCC population were 57.1% and 33.1% respectively, with median time to tumor progression of 7.4months (95% CI 4.7 to 19.4months). Median overall survival was 12.3months (95% CI 9.3 to 15.4months). CONCLUSIONS Tremelimumab in combination with tumor ablation is a potential new treatment for patients with advanced HCC, and leads to the accumulation of intratumoral CD8+ T cells. Positive clinical activity was seen, with a possible surrogate reduction in HCV viral load. LAY SUMMARY Studies have shown that the killing of tumors by direct methods (known as ablation) can result in the immune system being activated or switched on. The immune system could potentially also recognize and kill the cancer that is left behind. There are new drugs available known as immune checkpoint inhibitors which could enhance this effect. Here, we test one of these drugs (tremelimumab) together with ablation. CLINICAL TRIAL NUMBER ClinicalTrials.gov: NCT01853618.

Population attributable fractions of risk factors for hepatocellular carcinoma in the United States

Hepatocellular carcinoma (HCC) incidence has been increasing in the United States for several decades; and, as the incidence of hepatitis C virus (HCV) infection declines and the prevalence of metabolic disorders rises, the proportion of HCC attributable to various risk factors may be changing.

Earlier presentation and application of curative treatments in hepatocellular carcinoma

The purpose of the study was to assess the use of curative therapies for hepatocellular carcinoma (HCC) in the population. HCC treatment patterns were examined in Surveillance, Epidemiology, and End Results (SEER) 18 registries (28% of U.S.). Joinpoint regression analyses were performed to assess 2000‐2010 incidence trends by tumor size, count, and receipt of potentially curative treatments (transplantation, resection, and ablation). SEER‐Medicare data enabled evaluation of treatment patterns including receipt of sorafenib or transarterial chemoembolization (TACE) by HCC‐associated comorbidities. Diagnoses of tumors ≤5.0 cm in diameter significantly increased during 2000‐2010, surpassing diagnosis of larger tumors. Overall, 23% of cases received potentially curative treatment. Joinpoint models indicated incidence rates of treatment with curative intent increased 17.6% per year during 2000‐2005, then declined by −2.9% per year during 2005‐2010 (P < 0.001). Among HCC cases with a single tumor ≤5.0 cm and no extension beyond the liver, use of ablative therapy significantly increased during 2000‐2010. Use of invasive surgery for single tumors, regardless of size, significantly increased during the initial years of the decade, then plateaued. The group most likely to receive curative treatment in the SEER‐Medicare cases was patients with one, small tumor confined to the liver (657 of 1,597 cases, 41%), with no difference in treatment by hepatic comorbidity status (P = 0.24). A higher proportion of cases with reported liver‐associated comorbidities were, however, diagnosed with tumors ≤5.0 cm in diameter (1,745 0f 2,464, 71%) compared to patients with no reported comorbidities (996 of 2,596, 38%, P < 0.001). Conclusion: Although more HCC patients were diagnosed with early disease over time, the use of curative treatments in this patient group has recently plateaued. Efforts to identify and treat more eligible candidates for curative therapy could be beneficial. (Hepatology 2014;60:1637–1644)

A phase II study of TRC105 in patients with hepatocellular carcinoma who have progressed on sorafenib

Background Endoglin is an endothelial cell membrane receptor essential for angiogenesis and highly expressed on the vasculature of many tumor types, including hepatocellular carcinoma (HCC). TRC105 is a chimeric IgG1 anti-CD105 monoclonal antibody that inhibits angiogenesis and tumor growth by endothelial cell growth inhibition, ADCC and apoptosis, and complements VEGF inhibitors. Objective The aim of this phase II study was to evaluate the efficacy of anti-endoglin therapy with TRC105 in patients with advanced HCC, post-sorafenib. Methods Patients with HCC and compensated liver function (Childs-Pugh A/B7), ECOG 0/1, were enrolled to a single-arm, phase II study of TRC105 15 mg/kg IV every two weeks. Patients must have progressed on or been intolerant of prior sorafenib. A Simon optimal two-stage design was employed with a 50% four-month PFS target for progression to the second stage. Correlative biomarkers evaluated included DCE-MRI as well as plasma levels of angiogenic biomarkers and soluble CD105. Results A total accrual of 27 patients was planned. However, because of lack of efficacy and in accordance with the Simon two-stage design, 11 patients were enrolled. There were no grade 3/4 treatment-related toxicities. Most frequent toxicities were headache (G2; N = 3) and epistaxis (G1; N = 4). One patient had a confirmed partial response by standard RECIST criteria and biologic response on DCE-MRI but the four-month PFS was insufficient to proceed to the second stage of the study. Conclusions: TRC105 was well tolerated in this HCC population following sorafenib. Although there was evidence of clinical activity, this did not meet prespecified criteria to proceed to the second stage. TRC105 development in HCC continues as combination therapy with sorafenib.

Pancreatic Squamous Cell Carcinoma: A Population-Based Study of Epidemiology, Clinicopathologic Characteristics and Outcomes.

Objectives Squamous metaplasia is commonly detected in pancreatic parenchyma; however, primary pancreatic squamous cell carcinoma (SCC) is a rare malignancy with unknown incidence and unclear prognosis. Methods Surveillance, Epidemiology, and End Results (SEER) registries were examined identifying pancreatic SCC and adenocarcinoma cases from 2000 to 2012. Age-adjusted incidence rates were calculated. Patients with SCC versus adenocarcinoma were compared by clinical features and relative survival outcomes. Results We identified 214 patients with SCC and 72,860 with adenocarcinoma. For SCC, incidence rates tripled between 2000 and 2012. Significantly higher SCC incidence rates were observed in older age groups, blacks, and males. Greater proportion of patients with SCC than those with adenocarcinoma had poorly differentiated histology (73.0% vs 43.7%, P < 0.001). In both subtypes, majority of patients had stage IV disease, 59.0% for adenocarcinoma versus 62.6% for SCC. The 1- and 2-year relative survival rate was significantly lower in patients with SCC versus adenocarcinoma. The 1-year relative survival was 14.0% (95% confidence interval, 9.5%–19.4%) for SCC, compared with 24.5% (95% confidence interval, 24.2%–24.8%) for adenocarcinoma. Conclusions Although primary pancreatic SCC is a rare neoplasm, incidence rates for this subtype are increasing. Relative to adenocarcinoma, pancreatic SCC is characterized by poorly differentiated histology and worse survival.

Modulation of tumor eIF4E by antisense inhibition: A phase I/II translational clinical trial of ISIS 183750 – an antisense oligonucleotide against eIF4E – in combination with irinotecan in solid tumors and irinotecan‐refractory colorectal cancer

The eukaryotic translation initiation factor 4E (eIF4E) is a potent oncogene that is found to be dysregulated in 30% of human cancer, including colorectal carcinogenesis (CRC). ISIS 183750 is a second‐generation antisense oligonucleotide (ASO) designed to inhibit the production of the eIF4E protein. In preclinical studies we found that EIF4e ASOs reduced expression of EIF4e mRNA and inhibited proliferation of colorectal carcinoma cells. An additive antiproliferative effect was observed in combination with irinotecan. We then performed a clinical trial evaluating this combination in patients with refractory cancer. No dose‐limiting toxicities were seen but based on pharmacokinetic data and tolerability the dose of irinotecan was reduced to 160 mg/m2 biweekly. Efficacy was evaluated in 15 patients with irinotecan‐refractory colorectal cancer. The median time of disease control was 22.1 weeks. After ISIS 183750 treatment, peripheral blood levels of eIF4E mRNA were decreased in 13 of 19 patients. Matched pre‐ and posttreatment tumor biopsies showed decreased eIF4E mRNA levels in five of nine patients. In tumor tissue, the intracellular and stromal presence of ISIS 183750 was detected by IHC in all biopsied patients. Although there were no objective responses stable disease was seen in seven of 15 (47%) patients who were progressing before study entry, six of whom were stable at the time of the week 16 CT scan. We were also able to confirm through mandatory pre‐ and posttherapy tumor biopsies penetration of the ASO into the site of metastasis.

Phase I and Preliminary Phase II Study of TRC105 in Combination with Sorafenib in Hepatocellular Carcinoma

Purpose: Endoglin (CD105) is an endothelial cell membrane receptor highly expressed on proliferating tumor vasculature, including that of hepatocellular carcinoma (HCC), and is associated with poor prognosis. Endoglin is essential for angiogenesis, and its expression is induced by hypoxia and VEGF pathway inhibition. TRC105 is a chimeric IgG1 CD105 mAb that inhibits angiogenesis and causes antibody-dependent cellular cytotoxicity and apoptosis of proliferating endothelium. Experimental Design: Patients with HCC (Child–Pugh A/B7), ECOG 0/1, were enrolled in a phase I study of TRC105 at 3, 6, 10, and 15 mg/kg every 2 weeks given with sorafenib 400 mg twice daily. Correlative biomarkers included DCE-MRI and plasma levels of angiogenic factors, including soluble endoglin. Pharmacokinetics were assessed in serum. Results: Twenty-six patients were enrolled, of whom 25 received treatment, 15 with cirrhosis. Hep B/C: 3/15; M:F 19:6; mean age of 60 (range, 18–76); 1 DLT (grade 3 AST) occurred at 10 mg/kg. The most frequent toxicity was low-grade epistaxis, a known toxicity of TRC105. One patient experienced an infusion reaction and was replaced. One patient with coronary stenosis developed a fatal myocardial infarction, and one patient developed G3 cerebral tumor hemorrhage. MTD was not established and DL4 (15 mg/kg) was expanded. The overall response rate in 24 evaluable patients at all 4 dose levels was 21% [95% confidence interval (CI), 7.1–42.2], and 25% (95% CI, 8.7–49.1) in patients with measureable disease. Four patients had confirmed stable disease, one of whom was treated for 22 months. Median progression-free survival (PFS) for 24 patients evaluable for PFS was 3.8 months (95% CI, 3.2–5.6 months); median overall survival was 15.5 months (95% CI, 8.5–26.3 months). Conclusions: TRC105 combined with sorafenib was well tolerated at the recommended single agent doses of both drugs. Encouraging evidence of activity to date (PR rate 25%) was observed, and the study is now continuing to recruit in the phase II stage as a multicenter study to confirm activity of the combination. Clin Cancer Res; 23(16); 4633–41. ©2017 AACR.

Pancreatic squamous cell carcinoma: Epidemiology, clinicopathologic characteristics, and outcomes.

220 Background: Although squamous metaplasia is commonly detected in pancreatic parenchyma, primary pancreatic squamous cell carcinoma (SCC) is a rare malignancy with unknown incidence and unclear prognosis. Methods: Using SEER-18 database primary code C25 in conjunction with histology codes for SCC (8052-8053, 8070-8078, 8083-8084) and for adenocarcinoma (AC) (8052-8053, 807-8078, 8083-8084), we identified cases diagnosed from 2000 to 2012. Age-adjusted incidence rates and trends over time were calculated. Patients with SCC were compared with AC by clinical features (TNM categories and histological differentiation), and 1-year and 2-year relative survival (RS) outcomes. Chi-square tests for categorical variables and t-tests for continuous variables were conducted. Kaplan-Meier method was used to estimate RS and Z-test was used to compare RS rates. SEERStat and GraphPad were used for analysis. Results: We identified 214 patients with microscopically confirmed SCC and 72,860 patients with AC. SCC constitut...

Abstract 3421: Epidemiology and survival in patients with extragastric signet ring carcinoma

Background: Signet ring carcinoma (SRC) is a distinct histological phenotype of adenocarcinoma. There are only a few published studies specifying the epidemiology of SRC with extragastric presentation. The purpose of our study was to define the most common primary sites of extragastric SRC, determine the incidence, and to compare survival by primary site and disease stage. Methods: The Surveillance Epidemiology and End Result (SEER) database was examined from 2000 to 2012 in order to identify SRC histology (8490) and determine its most common primary sites, incidence, and survival by site and stage. The five most common primary extragastric sites were identified by utilizing ICD-0-3/WHO 2008 classification. Age-adjusted incidence rates for extragastric SRC were calculated and compared to gastric SRC. Relative survival (RS) and overall survival (OS) at 1 and 3 years were analyzed by primary site and stage using Kaplan-Meier method. Chi-square test was used for categorical variables. Results: A total of 24,522 histologically confirmed cases of SRC were identified, and SRC comprised 0.5% of all malignant neoplasms. Among cases with known histological grade, 89.7% had poorly differentiated tumors. Overall, digestive system origin was recorded for 90% of SRC cases. Approximately half (44.2%) of primary SRC tumors were detected outside of the stomach. The most common primary sites for extragastric SRC were colon (40.5%), esophagus (11.9%), rectum (9.8%), lung/bronchus (7.3%), and pancreas (4.7%). The incidence rates for common extragastric SRC were much lower than for gastric SRC, and were higher for males than females (p Conclusion: Our study indicated that extragastric SRC most commonly occurs in the colorectum, esophagus and lung/bronchus. We confirmed that the primary site substantially impacts survival. Thus, development of unique molecular or histologic markers may help to identify the organ of origin and thereby determine prognosis in these phenotypically similar neoplasms. Citation Format: Chul Kim, Susanna Ulahannan, Julius Strauss, Jaydira Del Rivero, Austin Duffy, Tim F. Greten, Oxana V. Makarova-Rusher. Epidemiology and survival in patients with extragastric signet ring carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3421.

Abstract 5015: Pretreatment carcinoembryonic antigen levels predict survival in patients with rectal adenocarcinoma

Background: Population-based studies have reported elevated Carcinoembryonic Antigen (CEA) level as an independent prognostic factor in patients with colon cancer, thus supporting inclusion of CEA-based C stage in classical TNM staging for colon cancer. However, the effect of C-stage incorporation on outcomes for patients with rectal adenocarcinoma is unknown. Methods: The Surveillance, Epidemiology and End Result (SEER) database was used to collect data from 2004 to 2007 for patients with rectal adenocarcinoma by topography code C20.9 and histology codes 8140-8144, 8210-8211, 8220-8221, 8260-8263, 8440, 8480-8481, and 8490. CEA stage C0 = normal CEA or C1 = elevated CEA was assigned to patients with known pretreatment CEA levels. Observed survival (OS) by American Joint Committee on Cancer (AJCC) stages I-IV and CEA stage C0 or 1 was determined using Kaplan Meier method. Relative survival (RS) as a net measure of cancer survival adjusted for sex, race, age and date was calculated in addition to observed survival (OS). Log-rank was used to compare observed survival. Z-test with corresponding p values was used to compare 5-year relative survival. Results: We identified 25,241 patients with a record of histologically confirmed invasive rectal adenocarcinoma. Approximately half (N = 13,151) of these patients had records of pretreatment CEA levels: N = 6,360 stage C1, N = 6,690 stage C0 and a small number (101) with borderline CEA levels. Mean age at diagnosis was similar in both groups, 64.2 for C0 and 64.7 for C1. Among patients with C1 disease the leading AJCC stage was distant metastatic, stage IV (33.8%) followed by 25.8% stage III, 20.7% stage II, 13.8% stage I, and 5.9% unknown stage. In contrast to CI disease, the most common stage for C0 was stage I (35.2%), and only 6.3% of patients with C0 were diagnosed with stage IV disease. Observed survival by each of I-IV AJCC TNM stages was decreased for C1 stage relative to C0, p Conclusion: Our study suggests that pretreatment CEA levels predict survival in patients with rectal adenocarcinoma, in accordance with previous data in colon cancer. Therefore, our study supports C-stage inclusion in AJCC TNM staging for this neoplasm. Further prospective confirmatory studies are warranted. Citation Format: Oxana V. Makarova-Rusher, Julius Strauss, Susanna Ulahannan, Chul Kim, Jaydira Del Rivero, Austin Duffy, Tim F. Greten. Pretreatment carcinoembryonic antigen levels predict survival in patients with rectal adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5015.