Citations

Abstract Background: Immunotherapy targeting tumor-associated antigens aberrantly expressed on colorectal cancers and adenomatous polyps offers the potential for a relatively non-invasive and non-toxic prevention strategy, and because of the specificity of the immune response and its long-term memory, the potential for prolonged protection. In a double-blind randomized trial in patients with a diagnosis of advanced colorectal adenomas within the previous year, we are evaluating MUC1 vaccine with the TLR-3 agonist polyICLC (Hiltonol®) as an adjuvant, for its immunogenicity and effect on colorectal adenoma recurrence at follow up colonoscopy. Aim: We report on a primary endpoint, MUC1 immunogenicity at week 12 (following vaccine or placebo administration at 0, 2, and 10 weeks), and on determinants of the immune response and vaccine toxicity. Methods: Subjects with an advanced adenoma (defined as ≥1cm, tubulovillous or villous histology, or with HGD) were randomized. Response to the vaccine was assessed by monitoring IgG anti-MUC1 antibody titer ratio; defined as t12/t0, where t0 is the initial titer measured prior to vaccination, and t12 is the titer drawn at 12 weeks. A ratio of 2.0 was used as the primary definition of a significant immune response. T Regulatory and myleoid derived suppressor cell (MDSC) levels at baseline were assessed in relation to vaccine response. Adverse events (AEs) were recorded according to NCI Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Results: 102 subjects were randomized at 6 centers, 52 received MUC1 vaccine and 50 placebo. Subjects had a mean age of 59.4±7.0 (range 40-70) years, 60.8% were male, 88.2% were white, and 18.6% Hispanic or Latino. At 12 weeks the IgG ratio was ≥2.0 in 13/52 (25%) of patients receiving vaccine (ratio range 2.9-17.3), vs. 0/50 in placebo group (P=.0001), and was ≥1.5 in 19/52 (36.5%) of patients receiving vaccine compared to 1/50 (2%) in placebo group (P<.0001). In the vaccinated group, the IgG ratio was ≥2.0 in 45% of women (9/20) vs. 12.5% of men (4/32) (P=0.009) and ≥1.5 in 55% of women (11/20) vs. 25% of men (8/32) (P=0.03). In the vaccinated group, reduced levels of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) pre-vaccination were associated with response, 0.2±0.1 among responders (n=13) vs. 0.8±1.1 among non-responders (N=39) (p=0.0006) whereas monocytic MDSC and T regulatory cells (CD4+CD25, Foxp3) were not. There were no grade 3 adverse events (AE) possibly or probably related to the vaccine. The most common AE was an injection site reaction (grade 1 or 2) which occurred in 80.8% (n=42/52) in vaccine group vs. 6.0% in the placebo group (3/50). Conclusions: Subjects with an advanced adenoma receiving MUC1 vaccine compared with a placebo are significantly more likely to develop an anti-IgG MUC1 immune response at 12 weeks. Women and subjects with lower circulating PMN-MDSC levels at baseline were more likely to respond. The vaccine was well tolerated. Follow up for the effect of the vaccine on adenomatous polyp recurrence is ongoing. Citation Format: Robert E. Schoen, Lisa A. Boardman, Marcia Cruz-Correa, Ajay Bansal, Pamela L. Beatty, David Kastenberg, Chin Hur, Lynda Dzubinski, Luz Rodriguez, Andres Salazar, John McKolanis, Drew Seisler, Nathan R. Foster, May-Yin Polley, Paul J. Limburg, Olivera J. Finn. Randomized, double-blind, placebo-controlled immunoprevention trial with MUC1 vaccine in patients with newly diagnosed advanced adenomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-305.

Abstract Recently, the use of oncolytic viruses encoding the sodium-iodide symporter (NIS) has become an attractive approach to achieve radionuclide imaging of cancer. However, the potential of virus-induced NIS expression to facilitate therapy with radioactive 131I has not been fully explored. We designed a tumor-selective, infectivity-improved oncolytic adenovirus (Ad5/3-Cox2-NIS-ADP) modified to express high quantities of NIS. This virus induced radioisotope uptake in prostate and lung cancer cells and facilitated SPECT/CT imaging, but more importantly, supported the effective therapy with 131I. In our original vector, enhanced oncolysis was mediated by overexpression of adenoviral death protein (ADP). Although this structure was operative in detection and therapeutic regimens, we were concerned that the cytolytic effect of ADP may affect NIS membrane localization, and diminish its effectiveness as a theranostic tool. We therefore designed an identical Ad5/3-Cox2-NIS-ADP-deleted virus {ADP(-)} and assessed the impact of ADP on NIS expression and radioisotope uptake. Western blot and immunocytochemical analyses of pancreatic cancer cells infected with ADP(-) demonstrated higher NIS levels when compared to the ADP(+) counterpart. This correlated with an improved 125I uptake in vitro. SPECT/CT imaging studies assessing 99mTcO4- accumulation in mice to visualize pancreatic adenocarcinoma (PDAC) using patient-derived xenografts (PDX) showed that a single dose of ADP(-) accumulated far greater levels of 99mTcO4- when compared to ADP(+). Remarkably, ADP(-) produced stronger signal that was maintained up until day 32, and this outlasted ADP(+) and the control vector, replication-deficient AdCMV-NIS, currently employed in a clinical trial. Notably, within the PDAC, ADP(-) showed a distinct NIS cell membrane distribution pattern as it co-localized with cell membrane bound-cytokeratin-4. Unlike ADP(-), ADP(+) produced a punctate NIS staining pattern, with little to no cell membrane localization. These results support our hypothesis that ADP-cytolytic effect reduces NIS membrane localization, subsequently affecting radionuclide uptake. To evaluate the therapeutic potential of NIS-based radiotherapy, we treated mice bearing PDAC tumors with virotherapy alone or in combination with 131I. NIS-expressing OAds in combination with 131I significantly reduced tumor growth when compared to viro- or radiotherapy alone. The therapeutic effect in mice treated with ADP(-) combined with 131I outperformed that with ADP(+) or AdCMV-NIS vectors. Quantitative analyses of 131I uptake in tumor tissues with a gamma counter showed a clear trend where ADP(-) retained higher 131I uptake than ADP(+). These findings support the clinical applicability of the ADP-deleted OAd as the more sensitive tool for NIS-based cancer diagnosis and therapy. We are currently investigating the biodistributon and toxicity of our vectors in a pig model. Citation Format: Lisa Koodie, Eriko Iguchi Kawakami, Kari Jacobsen, Zuzan Cayci, Andrew Taylor, Edward W. Greeno, Robert J. Schumacher, John C. Morris, Martin E. Fernandez-Zapico, Julia Davydova. A novel oncolytic adenovirus for radioiodine therapy and imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5925.

Abstract Background: Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries and the incidence and mortality of EC continue to rise in the US. When detected early, EC is highly curable, suggesting that early detection strategies could reduce EC mortality. Women who develop EC often have a prolonged history of abnormal bleeding, offering a window for identifying many at-risk women prior to the development of advanced cancer. To evaluate risk prediction, novel sampling and early detection strategies in women at increased risk of EC, we established a prospective cohort of women with abnormal bleeding that is followed for endometrial hyperplasia and cancer endpoints. Methods: We consecutively enrolled women ≥45 years old presenting to the Mayo Clinic for evaluation of abnormal uterine bleeding (AUB), postmenopausal bleeding (PMB), thickened endometrial stripe (ES) on imaging, or Lynch Syndrome (LS). From all women, an intravaginal tampon and an endometrial brushing via Tao brush were collected before endometrial biopsy. Epidemiological EC risk factor data, clinical data, and endometrial biopsy histology results were abstracted from medical records. Absolute risk of endometrial hyperplasia and EC were calculated overall and in strata based on clinical symptoms and risk factors. Results: Among the first 1,000 women enrolled into the study, 712 (71%) were overweight or obese, 534 (53%) were postmenopausal, and 214 (22%) were current hormone replacement therapy (HRT) users. Endometrial biopsy and, if indicated, subsequent hysterectomy, detected 39 ECs, 16 atypical hyperplasias, and 28 hyperplasias without atypia at baseline evaluation. Among 534 postmenopausal women, 453 (85%) reported any type of bleeding, with spotting (39%) and light bleeding (27%) being more common than heavy bleeding (14%). Among perimenopausal women with AUB (n=452), the absolute risk of EC at baseline was 0.9% and among women with PMB, the absolute risk of EC at baseline was 7.5%. Among women with PMB, EC risk was modified by HRT use (risk of 2.6% in women on HRT and 8.2% in women not on HRT, respectively), obesity (risk of 5.3%, 8.1% and 9.5% for women with normal, overweight, and obese BMI, respectively), and type of bleeding (risk of 9.7%, 4.9%, and 8.2% in women with spotting, light or heavy bleeding, respectively). Discussion: While risk of endometrial cancer in perimenopausal women with AUB is low, approximately 8% of women presenting for clinical work up of PMB have underlying EC. Clinical presentation and risk factors modify the absolute risk of EC and may inform clinical management. Additional recruitment and prospective follow-up is underway to improve estimates of short- and long-term EC risk in women with PMB. With its collection of tampon and Tao brush samples, the study will provide a unique resource to evaluate molecular markers of EC and EC risk in elevated-risk women. Citation Format: Nicolas A. Wentzensen, Megan Clarke, Viji Shridhar, Maureen Lemens, Matthew Hopkins, Lisa Ahlberg, Shannon Laughlin-Tommaso, Karl Podratz, Mark Sherman, Jamie Bakkum-Gamez. A prospective study of endometrial cancer detection in women presenting for evaluation of abnormal peri- and postmenopausal bleeding [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2203.

Abstract Oncology has undergone major changes in systemic treatment options, from chemotherapy to antiangiogenic agents to tyrosine-kinase inhibitors to immunotherapy. Historically, a therapeutic agent is tested in separate trials as monotherapy or combined with investigational or approved agents/modalities, to determine antitumor activity in each histology based on the premise that each histology responds differently to the same treatment. This paradigm is time consuming and may or may not make use of molecular characterization to test each agent in each histology. However, with the expansion of biologic understanding and development of various biomarkers, e.g., estrogen receptor and Her 2 amplification, we move beyond the basic paradigm of general histology to one in which treatment is based upon molecular characteristics of the tumor. Examples of recent discoveries from this more modern paradigm are (1) multiple histologies sharing a common molecular profile and (2) a subset within a single histology having a given molecular characteristic. Various agents have been tested singularly in terms of molecular aberrations and histology, e.g., ALK inhibitors and NSCLC. However, with the rapid increase in the number of targeted agents in development, more facile and efficient clinical trial designs are needed. The National Cancer Institute (NCI) and ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) collaborated in designing the Molecular Analysis for Therapy Choice trial (NCI-MATCH or EAY131), the first large-scale signal-finding precision medicine oncology trial in the United States to incorporate centralized NGS testing to direct patients to parallel (nonrandomized) phase II treatment arms under a master protocol. The trial is being conducted by the NCI National Clinical Trials Network (NCTN), with ECOG-ACRIN leading the trial. More than 100 investigators from across the NCTN adult cancer-oriented member groups (Alliance for Clinical Trials in Oncology, ECOG-ACRIN, NRG Oncology, and SWOG) have worked collaboratively to design and lead what is currently 30 treatment arms (subprotocols), with more arms in development. Wide-scale NCTN investigator involvement ensures use of the latest knowledge to define the actionable mutations required for eligibility and to make evidence-based selections of experimental agents. In NCI-MATCH, patients are assigned treatment based on the genomic alterations found in their tumors through genomic sequencing and other tests at the time of initial enrollment for screening. Unlike other phase II trials, each arm is open to advanced solid tumors, lymphomas, or myeloma that share a set of molecular aberrations, not restricted to a single histology. This strategy accommodates and encourages enrollment of rare tumors for which there are often no standard treatments and limited clinical trial options. NCI-MATCH has 10-30 concurrent treatment arms available to patients at any given time, testing both investigational agents and FDA-approved drugs for new indications. Most treatment arms have an enrollment goal of 35 patients, with some arms that address tumor gene variants of higher prevalence expanded to 70 patients. Together, the NCTN and NCI Community Oncology Research Program provide infrastructure for many clinical sites (>1100) to participate, providing ready access to physicians and patients; screening enrollment has occurred in all 50 states in the U.S, the District of Columbia, and Puerto Rico. A specific assay was developed for the trial (the MATCH assay), and a laboratory network was organized to rapidly process the tissue and efficiently interrogate for mutations. NCI and ECOG-ACRIN statisticians developed the analysis plan and are currently maintaining data that are closely monitored by safety experts for any adverse event signals. Lastly, a bioinformatics system (MATCHbox) was developed to coordinate molecular data collection and support rule-based decision-making based on those data. Because genomics in oncology is rapidly expanding and evolving, NCI-MATCH required flexibility to accommodate brisker screening accrual than anticipated, and adaptation to constantly emerging information about new drugs and new molecular alterations. The goal to sequence the tumors of 6,000 patients with NCI funding was achieved two years ahead of schedule, but that cohort was not sufficient to fill all the arms—in particular, those aimed at the most rarely occurring tumor gene aberrations. Currently, the goal for the trial is to complete the open treatment arms by allowing for designated commercial and academic laboratories to notify ordering physicians when genomic tests they ordered to guide clinical care indicate a potential eligibility to a NCI-MATCH arm with a rare variant and allow for enrollment to the relevant treatment subprotocol if the patient meets all subprotocol eligibility criteria. The tissue confirmation of the molecular abnormality on the MATCH assay by the central laboratories will be accomplished after subprotocol enrollment so that patient treatment will not be delayed for confirmation. A demonstration project is now under way to test the applicability of this approach and potentially develop common standards for future use. With tumor sequencing becoming a more and more common practice in oncology, this may allow patients with mutations of low prevalence to have investigational treatment options. NCI-MATCH is expanding its panel and definition of actionable mutations to allow greater flexibility to incorporate in real time new mutations supported with adequate levels of evidence. The valuable genomic and clinical outcome data collected in the trial will permit evaluation of efficacy of targeting certain actionable mutations with a specific agent. In addition, biospecimens are being collected to build a rich resource for conducting auxiliary biology studies that may answer questions about prevalence of mutations in the metastatic setting, prevalence of mutations in rare histologies, and resistance mechanisms of various targeted therapy. At this meeting, two abstracts will provide an overall trial update and present information about the prevalence of mismatch repair deficiency (dMMR) in the centrally screened population. Citation Format: Alice P. Chen, Peter J. O'Dwyer, Lyndsay Harris, Barbara A. Conley, Stanley R. Hamilton, Mickey Williams, Robert J. Gray, Shuli Li, Lisa M. McShane, Lawrence V. Rubinstein, Susanna I. Lee, Shaji Kumar, Edith P. Mitchell, James A. Zwiebel, Constantine A. Gatsonis, Lalitha K. Shankar, Paolo F. Caimi, Carlos L. Arteaga, A John Iafrate, Jeffrey Sklar, Richard F. Little, Keith T. Flaherty. NCI-MATCH: A new paradigm in the era of genomic oncology [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr PL03-01.

Objectives: 1) Describe the genetic alterations discovered in a series of sporadic vestibular schwannomas (VS). 2) Identify if more clinically aggressive variants possess different genetic alterations compared to more indolent-behaving VS. Methods: Fresh frozen tumor and matched peripheral blood leukocytes from 23 individuals with sporadic VS were analyzed using whole-exome sequencing, tumor whole transcriptome expression profiling (mRNA-Seq), and tumor mate-pair analysis. Source cases included tumors with fast preoperative growth, giant tumors in young patients, tumors with macrocystic change, recurrent tumors following radiation or microsurgery, and indolent small tumors with minimal or no growth before surgery. Somatic and germ-line alterations of the NF2 gene and beyond the NF2 locus were identified and analyzed using complementing analyses. Results: Biallelic somatic events involving the NF2 gene were discovered in every analyzed tumor specimen with no concurrent NF2 variants identified in matching peripheral blood specimens. Thirteen tumors showed loss of one chromosome 22 (ch22), 4 tumors showed copy-neutral 22q loss of heterozygosity, and 31 unique small variants in the NF2 gene were discovered. Of the latter, 10 were essential splice site, 11 frame shift, 7 stop gain, 2 missense, and 1 in-frame mutation. No other common or recurring NF2 mutations were identified. However, several other notable large chromosomal aberrations were discovered including 2 tumors with loss of a chromosome 21, 3 with loss of an X or Y chromosome, 1 with copy-neutral loss of heterozygosity in chromosome 15, and 1 with loss of 18p and 16q. All of these other major chromosomal abnormalities only occurred in tumors demonstrating a more aggressive phenotype. Conclusions: To date, few studies have used whole-exome sequencing, mate-pair analysis, and RNA-seq to profile genome-wide alterations in sporadic VS. Using high-throughput deep sequencing, “two-hit” alterations in the NF2 gene were identified in every tumor and were not present in peripheral blood supporting that all events were somatic. Type of NF2 gene alteration and accessory mutations outside the NF2 locus may predict phenotypic expression and clinical course.

Little is known about how adolescents’ and parents’ thoughts about participation in clinical trials change over time. In this study, adolescent (14-17 years)–parent dyads were asked about willingness to participate in a hypothetical reproductive health study. A year later, they were asked how their thoughts about the study had changed. Qualitative responses were coded and analyzed using framework analysis. Thirty-two percent of adolescents and 18% of parents reported changes in thoughts; reasons included general changes in perception, clearer understanding, new knowledge or experiences, increased maturity/age of adolescents, and changes in participants independent of the study. Adolescents and parents may benefit from learning about studies multiple times, and investigators should account for development and new experiences to optimize adolescent research enrollment.

SummaryMantle cell lymphoma (MCL) is still considered incurable and the course of the disease is highly variable. Established risk factors include the Mantle Cell Lymphoma International Prognostic Index (MIPI) and the quantification of the proliferation rate of the tumour cells, e.g. by Ki‐67 immunohistochemistry. In this study, we aimed to validate the prognostic value of the gene expression‐based MCL35 proliferation assay in patient cohorts from randomized trials of the European Mantle Cell Lymphoma Network. Using this assay, we analysed the gene expression proliferation signature in routine diagnostic lymph node specimens from MCL Younger and MCL Elderly trial patients, and the calculated MCL35 score was used to assign MCL patients to low (61%), standard (27%) or high (12%) risk groups with significantly different outcomes. We confirm here in our prospective clinical trial cohort of MCL patients, that the MCL35 assay is strongly prognostic, providing additional information to the Ki‐67 index and the MIPI. Thus, this robust assay may assist in making treatment decisions or in devising risk‐adapted prospective clinical trials in the future.

Purpose Intermediate-risk rhabdomyosarcoma (RMS) includes patients with either nonmetastatic, unresected embryonal RMS (ERMS) with an unfavorable primary site or nonmetastatic alveolar RMS (ARMS). The primary aim of this study was to improve the outcome of patients with intermediate-risk RMS by substituting vincristine and irinotecan (VI) for half of vincristine, dactinomycin, and cyclophosphamide (VAC) courses. All patients received a lower dose of cyclophosphamide and earlier radiation therapy than in previous trials. Patients and Methods Patients were randomly assigned at study entry to either VAC (cumulative cyclophosphamide dose, 16.8 g/m 2 ) or VAC/VI (cumulative cyclophosphamide dose, 8.4 g/m 2 ) for 42 weeks of therapy. Radiation therapy started at week 4, with individualized local control plans permitted for patients younger than 24 months. The primary study end point was event-free survival (EFS). The study design had an 80% power (5% one-sided α-level) to detect an improved long-term EFS from 65% (with VAC) to 76% (with VAC/VI). Results A total of 448 eligible patients were enrolled in the study. At a median follow-up of 4.8 years, the 4-year EFS was 63% with VAC and 59% with VAC/VI ( P = .51), and 4-year overall survival was 73% for VAC and 72% for VAC/VI ( P = .80). Within the ARMS and ERMS subgroups, no difference in outcome by treatment arm was found. Severe hematologic toxicity was less common with VAC/VI therapy. Conclusion The addition of VI to VAC did not improve EFS or OS for patients with intermediate-risk RMS. VAC/VI had less hematologic toxicity and a lower cumulative cyclophosphamide dose, making VAC/VI an alternative standard therapy for intermediate-risk RMS.

SummaryPatients with mantle cell lymphoma (MCL) generally have a dismal prognosis. Intensified induction treatment with rituximab and high dose cytarabine (R_HDAC), and consolidation with high‐dose therapy with autologous stem cell support has resulted in 10‐year overall survival (OS) higher than 60%. However, the clinical course varies. Diagnostic tools capable of stratifying patients include the MCL International Prognostic Index (MIPI), gene expression‐based proliferation signature, Ki‐67 proliferation index or tumour cell morphology. Here, we tested the performance of a newly developed Nanostring‐based RNA expression‐based proliferation assay (MCL35) on formalin‐fixed paraffin‐embedded tumour tissue from younger patients recruited in or treated according to Nordic MCL protocols compared to the prognosticators listed above. Seventy‐four patients were included and the assay performed well in all cases except four, which had inadequate RNA quality. The patients were evenly distributed in the MCL35 low‐, intermediate‐ and high‐risk categories. MCL35 low‐ and intermediate‐ risk groups had overlapping progression‐free survival (PFS), while patients in the high‐risk category had significantly inferior PFS. Combining MCL35 with MIPI or the MIPI‐C (MIPI with the addition of binary Ki67 score +/−30%) showed a better discrimination than either assessment alone. In conclusion, the MCL35 assay alone or combined with MIPI or MIPI‐C scores can identify patients who still have a dismal outcome despite intensified treatment.