Richmond, Ellen S.

Abstract Background: Immunoprevention via targeting antigens aberrantly expressed on colorectal cancers and adenomatous polyps offers the potential for a less invasive prevention strategy than endoscopic surveillance. Specificity of the immune response and long-term memory provide the potential for prolonged protection. Leveraging the infrastructure of the NCI-funded Cancer Prevention Network (CPN) consortium, we are conducting a double-blind randomized trial in individuals with a diagnosis of advanced colorectal adenomas within the previous year. We are evaluating MUC1 vaccine with the TLR-3 agonist polyICLC as an adjuvant, for its immunogenicity, ability to elicit immune memory and prevent recurrence of colorectal adenomas. Aims: We previously reported on the vaccine immunogenicity at week 12 (vaccine administered at 0, 2, and 10 weeks) compared to placebo. Here we report the ability of the vaccine to elicit long-term memory by measuring increase in anti-MUC1 antibody levels following a booster administered at one year. Methods: Subjects with endoscopically resected advanced adenoma (defined as ≥1cm, tubululovillous or villous histology, or with high grade dysplasia) were randomized. The primary endpoint was the response to the vaccine at week 12 assessed by monitoring anti-MUC1 IgG antibody titer ratio defined as t12/t0, where t0 was the titer pre-vaccination, and t12 was the titer at week 12. The key secondary endpoint was to assess anti-MUC1 IgG response at week 55 to a booster at week 52 in the vaccine arm compared to placebo. Results: 102 eligible subjects were randomized at 6 centers, 52 received MUC1 vaccine and 50 placebo. The mean age was 59.4±7.0 (range 40-70), 60.8% male, 88.2% white, and 18.6% Hispanic or Latino ethnicity. At 12 weeks the IgG ratio was ≥2.0 in 13/52 (25%) of individuals receiving vaccine (ratio range -0.5-17.3), vs. 0/50 in placebo group (2-sided p=.0001), and was ≥1.5 in 19/52 (36.5%) individuals receiving vaccine compared to 1/50 (2%) in placebo group (P<.0001). To evaluate immune memory, 1-year booster data available for 95 patients (51-MUC1, 44-placebo) were analyzed. 10/13 (76.9%) of the week 12 vs. week 0 vaccine responders showed a response at week 52 vs. baseline and 11/13 (84.6%) at week 55 vs. week 52. Using an IgG ratio of 2 (per-protocol), the response rate was 33% for MUC1 vs. 5% for placebo (1-sided p=0.0003). Using a ratio of 1.5 yielded similar results (37% MUC1 vs. 9% Placebo (1-sided p=0.0008). The MUC1 arm had significantly higher IgG at week 52 (1-sided p=0.0294), week 55 (1-sided p=0.0048), and significantly higher week 55 to week 52 IgG ratio values (1-sided p=0.0293). Conclusions: Subjects with a recent history of advanced adenoma receiving a MUC1 vaccine compared with a placebo were significantly more likely to develop an immune response at week 12, confirming the vaccine’s immunogenicity, and to respond again at week 55 to a booster injection on week 52, confirming the vaccine’s ability to elicit immune memory. Follow-up colonoscopy to evaluate the vaccine’s potential to lower adenomatous polyp recurrence rates are in progress. Citation Format: Olivera J. Finn, Lisa Boardman, Marcia Cruz-Correa, Ajay Bansal, David Kastenberg, Chin Hurr, Sharon Kaufman, Colleen Akerley, Lynda Dzubinski, April Felt, Karrie Fursa, L.M. Rodriguez, Ellen Richmond, Asad Umar, Eva Szabo, John McKolanis, Ryan McMurray, Nathan Foster, Andres Salazar, Paul Limburg, Robert Schoen. Randomized, double-blind, placebo-controlled trial of preventative MUC1 vaccine in patients with newly diagnosed advanced adenomas: Results from one-year booster [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT236.

Background and aim Although Non-steroidal anti-inflammatory drugs reduce colorectal adenoma burden in familial adenomatous polyposis (FAP), the utility of combining chemopreventive agents in FAP is not known. We conducted a randomised trial of celecoxib (CXB) versus CXB+diflouromethylornithine (DFMO) to determine the synergistic effect, if any. Methods The primary endpoint was % change in adenoma count in a defined field. Secondary endpoints were adenoma burden (weighted by adenoma diameter) and video review of entire colon/rectal segments. Adverse event (AEs) were monitored by National Cancer Institution toxicity criteria. Results 112 subjects were randomised: 60 men and 52 women at a mean age of 38 years. For the 89 patients who had landmark-matched polyp counts available at baseline and 6 months, the mean % change in adenoma count over the 6 months of trial was −13.0% for CXB+DFMO and −1.0% for CXB (p=0.69). Mean % change in adenoma burden was −40% (CXB+DFMO) vs −27% (CXB) (p=0.13). Video-based global polyp change was −0.80 for CXB+DFMO vs −0.33 for CXB (p=0.03). Fatigue was the only significant AE, worse on the CXB arm (p=0.02). Conclusions CXB combined with DFMO yielded moderate synergy according to a video-based global assessment. No significant difference in adenoma count, the primary endpoint, was seen between the two study arms. No evidence of DFMO-related ototoxicity was seen. There were no adverse cardiovascular outcomes in either trial arm and no significant increase in AEs in the CXB+DFMO arm of the trial. Differences in outcomes between primary and secondary endpoints may relate to sensitivity of the endpoint measures themselves. Trial registration number ClinicalTrials.gov number N01-CN95040.

Abstract Background: In patients with Barrett's esophagus, chronic reflux injury and inflammation are associated with esophageal adenocarcinoma, one of the most rapidly increasing lethal cancers. Epidemiological and preclinical studies support decreased risk of esophageal adenocarcinoma with NSAID use. Gastroesophageal refluxate contents can promote carcinogenesis in Barrett's metaplasia by activating AKT, which up regulates COX-2 expression and prostaglandin biosynthesis. We recently noted that neoplastic transformation in Barrett's esophagus is associated with increased AKT expression, particularly isoform AKT1. The AIM of this study is to investigate the effect of NSAID (Aspirin) use in patients with Barrett's esophagus on AKT1 expression using frozen tissue from the randomized, phase II trial of aspirin and esomeprazole for esophageal cancer chemoprevention in Barrett's esophagus patients and to assess the functional consequences of AKT1 expression in-vitro. Methods and Results: In a subset of patients (12 of 120 patients) with Barrett's esophagus who were randomized to placebo, lower dose (81 mg) or higher dose (325 mg) Aspirin for 4 weeks, both PCR and Western blot revealed marked reduction in AKT1 expression in patients who received 325 mg of Aspirin daily compared to patients who received placebo. Our in-vitro experiments support that AKT1 expression is functionally relevant to the process of carcinogenesis in Barrett's epithelial cells. Using adenovirus to induce AKT1 expression, we show that increased AKT1 expression increases Barrett's epithelial cell growth, facilitates RAS-mediated transformation of pre-neoplastic epithelial cells and promotes colony formation. Since AKT1 is known as Warburg kinase and regulates cellular glucose uptake to support aerobic glycolysis during growth de-regulation and neoplasia, we examined the uptake of fluorescent deoxyglucose analog (2-NBDG) in Barrett's epithelial cells transduced with AKT1 adenovirus. At 48 hrs, compared to control, AKT1 overexpression resulted in increased glucose uptake both by metaplastic and neoplastic Barrett's epithelial cells. Transcriptional repression of AKT1 abrogated the 2-NBDG uptake by these cells. Finally, we did pathway specific qPCRs and noted that use of Aspirin is associated with altered expression of chromatin remodelers that could down-regulate AKT1 expression. Conclusion: Collectively, our results demonstrate that Aspirin mediated down-regulation of Warburg kinase AKT1 in patients with Barrett?s esophagus is a novel mechanism for the regulation of Barrett?s epithelial cell growth. The in-depth characterization of molecular mechanisms is currently underway. This abstract is also presented as Poster A82. Citation Format: Navtej S. Buttar, Gary W. Falk, Cathrine J. DeMars, Sonia Chowdhury, Ahmed Elebiary, Anamay Sharma, Sidhartha Chaudhry, Nathan R. Foster, Katie L. Allen Ziegler, Yvonne Romero, Norman E. Marcon, Thomas Schnell, Douglas A. Corley, Prateek Sharma, Marcia R. Cruz-Correa, Chin Hur, David E. Fleischer, Amitabh Chak, Kenneth R. DeVault, David S. Weinberg, Gary Della’Zanna, Ellen Richmond, Thomas C. Smyrk, Sumithra Mandrekar, Paul J. Limburg. Aspirin mediated downregulation of Warburg kinase AKT1 in patients with Barrett's esophagus: Implications in neoplastic transformation. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr PR-03.

Abstract Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/advanced colorectal adenomas. Magnification chromoendoscopy (MCE) was performed to identify and characterize rectal aberrant crypt foci (ACF); eligibility criteria required five or more rectal ACFs at baseline. Intervention assignments were as follows: (a) atorvastatin 20 mg qd; (b) sulindac 150 mg bid; (c) oligofructose-enriched inulin (as ORAFTI®Synergy1) 6 gm bid; or (d) control (maltodextrin) 6 gm bid, for 6 months. Percent change in rectal ACF number (%ΔACF) within arm was the primary endpoint. Secondary endpoints included changes in proliferation (Ki67) and apoptosis (caspase-3), as measured from normal mucosa biopsy samples. Among 85 eligible randomized subjects, 76 (86%) completed the trial per protocol. The median (range) of rectal ACF was 9 (5–34) and 8 (0–37) at baseline and postintervention, respectively. The median (SD) for %ΔACF was 5.6 (−69% to 143%), −18.6 (−83% to 160%), −3.6 (−88% to 83%), and −10.0 (−100% to 117%) in the atorvastatin, sulindac, ORAFTI®Synergy1 and control arms, respectively. Neither within-arm (P = 0.12–0.59) nor between-arm (P = 0.30–0.92) comparisons of %ΔACF were statistically significant. The active and control interventions also seemed to have similar effects on mucosal proliferation and apoptosis (P > 0.05 for each comparison). Data from this multicenter, phase II trial do not provide convincing evidence of CRC risk reduction from 6-month interventions with atorvastatin, sulindac, or ORAFTI®Synergy1, although statistical power was limited by the relatively small sample size. Cancer Prev Res; 4(2); 259–69. ©2011 AACR.