Citations

Abstract Background: Obesity and diabetes are major modifiable risk factors for pancreatic cancer. Interactions between genetic variants and diabetes/obesity have not previously been comprehensively investigated in pancreatic cancer at the genome-wide level. Methods: We conducted a gene–environment interaction (GxE) analysis including 8,255 cases and 11,900 controls from four pancreatic cancer genome-wide association study (GWAS) datasets (Pancreatic Cancer Cohort Consortium I–III and Pancreatic Cancer Case Control Consortium). Obesity (body mass index ≥30 kg/m2) and diabetes (duration ≥3 years) were the environmental variables of interest. Approximately 870,000 SNPs (minor allele frequency ≥0.005, genotyped in at least one dataset) were analyzed. Case–control (CC), case-only (CO), and joint-effect test methods were used for SNP-level GxE analysis. As a complementary approach, gene-based GxE analysis was also performed. Age, sex, study site, and principal components accounting for population substructure were included as covariates. Meta-analysis was applied to combine individual GWAS summary statistics. Results: No genome-wide significant interactions (departures from a log-additive odds model) with diabetes or obesity were detected at the SNP level by the CC or CO approaches. The joint-effect test detected numerous genome-wide significant GxE signals in the GWAS main effects top hit regions, but the significance diminished after adjusting for the GWAS top hits. In the gene-based analysis, a significant interaction of diabetes with variants in the FAM63A (family with sequence similarity 63 member A) gene (significance threshold P < 1.25 × 10−6) was observed in the meta-analysis (PGxE = 1.2 ×10−6, PJoint = 4.2 ×10−7). Conclusions: This analysis did not find significant GxE interactions at the SNP level but found one significant interaction with diabetes at the gene level. A larger sample size might unveil additional genetic factors via GxE scans. Impact: This study may contribute to discovering the mechanism of diabetes-associated pancreatic cancer.

Background: Brugada syndrome (BrS) is an oligogenic arrhythmic disease with increased risk of sudden cardiac arrest. Several BrS or ECG traits-related single-nucleotide polymorphisms (SNPs) were identified through previous genome-wide association studies in white patients. We aimed to validate these SNPs in BrS patients in the Taiwanese population, assessing the cumulative effect of risk alleles and the BrS-polygenic risk score in predicting cardiac events. Methods: We genotyped 190 unrelated BrS patients using the TWB Array, and Taiwan Biobank was used as controls. SNPs not included in the array were imputed by IMPUTE2. Cox proportional hazards model was used to evaluate the associations between each particular SNP, the collective BrS-polygenic risk score, and clinical outcomes. Results: Of the 88 previously reported SNPs, 22 were validated in Taiwanese BrS patients ( P <0.05). Of the 22 SNPs, 2 (rs10428132 and rs9388451) were linked with susceptibility to BrS, 10 were SNPs previously reaching genome-wide significance, and 10 were SNPs associated with ECG traits. For the 3 most commonly reported SNPs, disease risk increased consistently with the number of risk alleles (odds ratio, 3.54; P trend =1.38×10 −9 for 5 risk alleles versus 1). Similar patterns were observed in both SCN5A mutation+ (odds ratio, 3.66; P trend =0.049) and SCN5A mutation− (odds ratio, 3.75; P trend =8.54×10 −9 ) subgroups. Furthermore, BrS patients without SCN5A mutations had more risk alleles than BrS patients with SCN5A mutations regardless of the range of polygenic risk scores. Three SNPs (rs4687718, rs7784776, and rs2968863) showed significant associations with the composite outcome (sudden cardiac arrest plus syncope, hazard ratio, 2.13, 1.48, and 0.41; P =0.02, 0.006, and 0.008, respectively). Conclusions: Our findings suggested that some SNPs associated with BrS or ECG traits exist across multiple populations. The cumulative risk of the BrS-related SNPs is similar to that in white BrS patients, but it appears to correlate with the absence of SCN5A mutations.

10029 Background: This is the first randomized trial testing the addition of an oncolytic virus to an immune checkpoint inhibitor for advanced melanoma. At the 3-year (yr) follow-up, the combination (combo) of T-VEC and ipi demonstrated durable and statistically superior objective response rate (ORR) over ipi alone (36.7% vs. 16.0%; odds ratio, 3.0; 95% Cl, 1.6–6.0; P = 0.002). Complete response (CR) rate was 21.4% with the combo and 6.0% with ipi. Median overall survival (OS) was not reached in either arm. In this post hoc analysis, we utilized the 3-yr landmark data to explore the relationship between CR and OS in the combo arm. Methods: Pts with unresectable, stage IIIB-IV melanoma were randomized 1:1 to receive combo or ipi alone. T-VEC was administered intratumorally on day 1 of week (wk) 1 at 106 plaque-forming units (PFU)/mL followed by subsequent doses at 108 PFU/mL on day 1 of wk 4, and every 2 wks thereafter. Ipi (3 mg/kg) was given every 3 wks starting on day 1 of wk 6 for up to 4 doses. Response was assessed by investigators per immune-related response criteria every 12 wks until disease progression. The primary endpoint was ORR; key secondary endpoints were OS, progression-free survival, and safety. Results: 198 pts were randomized (98 to combo; 100 to ipi). As of February 25, 2019, the median follow-up time was 40.0 mos (range: 0.2–63.7) for the combo arm. Among 98 pts who received combo, 21 (21.4%) had a best overall response of CR including 8 who converted from an initial partial response (PR), 15 (15.3%) had PR, 19 (19.4%) had stable disease, 30 (30.6%) had progressive disease, and 13 (13.2%) were unevaluable. Of 21 pts achieving CR, 17 (81%) had ECOG status of 0, 16 (76.2%) had stage IIIB-IVM1a disease, and 16 (76.2%) had no visceral metastases. Median duration of CR was not reached (range: 5.4[+]–58.2[+] mos); 19 of 21 CRs lasted more than 6 months. The baseline tumor burden was lower in pts with CR than in those with non-CR. Median OS was not reached in pts with CR (range: 25.1[+]–63.7[+] mos) and was 47.6 mos (range: 0.2[+]– 63.7[+] mos) in pts with non-CR (Log-rank P = 0.0005). The Kaplan–Meier estimated 3-year OS rate was 100.0% for patients with CR and 52.3% for those with non-CR. Conclusions: CR rate was higher with T-VEC plus ipi than with ipi alone in pts with advanced melanoma (21.4% vs. 6.0%). In the combo arm, CR was associated with prolonged OS, and pts with CR tended to have better ECOG performance status, earlier-stage disease, and lower baseline tumor burden, as compared with those with non-CR. Clinical trial information: NCT01740297.

e21631 Background: The efficacy of osimertinib in previously EGFR-TKI treated NSCLC patients without T790M mutation remains unclear in real-world practice. We investigated whether osimertinib can provide survival benefit in EGFR-mutant patients without T790M mutation after 1st/2nd generation TKI treatment. Methods: Between January 1, 2009, and March 31, 2019, 417 patients had stage III-IV NSCLC harboring EGFR mutation and 154 out of 417 patients receiving osimertinib as≥2nd-line EGFR-TKI treatment were identified at Mayo Clinic. The time to treatment failure of osimertinib was analyzed by the Kaplan-Meier (KM) estimates. The risk of death post diagnosis was analyzed by Cox proportional hazard models. Results: Among 417 EGFR-mutant patients, higher risk of death was found in patients with age above 65 years, non-adenocarcinoma, no surgery treatment, no radiation treatment, non-exon 19 deletion/exon 21 L858R mutation, higher ECOG PS (2-4), PD-L1 expression of 50% or more, bone metastasis, live metastasis, and adrenal metastasis (all p < 0.05). Moreover, osimertinib as ≥2nd-line TKI treatment in patients with or without T790M revealed lower risk of death compared to 1st/2nd generation TKI treatment without subsequent osimertinib (HR = 0.33; 0.46, and p = 0.0002; 0.0232, respectively). However, among patients receiving osimertinib as ≥2nd-line TKI treatment, patients with T790M did not have superior survival than those without (p = 0.2803). Among 154 patients receiving osimertinib, a higher risk of treatment failure for osimertinib was found in male (HR = 1.72; p = 0.0327), patients with 1st-line TKI duration ≤12 months (HR = 2.16; p = 0.0019), BMI drop > 10% (HR = 1.85; p = 0.0207), PD-L1 levels of 50% or more (HR = 4.28; p = 0.0008), and 1st-line TKI with afatinib (HR = 2.19; p = 0.0136). Nonetheless, osimertinib as ≥2nd-line TKI in patients without 790M mutation did not have higher risk of treatment failure than those with T790M (p = 0.1236). Conclusions: This is the first study to demonstrate that osimertinib can provide similar survival benefit in previously EGFR-TKI treated NSCLC patients without T790M mutation as those with T790M in real-world practice. Additionally, EGFR-mutant patients with PD-L1 expression ≥50% had a higher risk of treatment failure for osimertinib and worse overall survival than those with PD-L1 expression < 50% and may potentially gain benefit from optimizing treatment strategies including immunotherapy.

Abstract Objectives Distinguishing between T-cell and natural killer (NK)–cell neoplasms could be difficult given their overlapping immunophenotype. In this study, we investigated whether a flow cytometry assay with cytoplasmic staining for CD3 could be used for this purpose. Methods Flow cytometry immunophenotyping was performed on 19 surface CD3 (sCD3)–negative mature T-cell neoplasms, 10 sCD3-positive mature T-cell neoplasms, 13 mature NK-cell neoplasms, and 19 normal controls. In addition to routine antibody panels (CD2, sCD3, CD4, CD5, CD7, CD8, CD16, CD45, CD56, CD57, CD94, CD158a, CD158b, CD158e, NKG2A TCRγ/δ), cytoplasmic staining for a monoclonal CD3 antibody (clone SK7/Leu-4) was assessed in all cases. A molecular study for T-cell receptor (TCR) gene rearrangement and an immunohistochemical study for TCRβ were performed. Results Our data showed all T-cell neoplasms were uniformly positive for cytoplasmic CD3 (cCD3) regardless of sCD3 expression, whereas 85% of NK-cell neoplasms completely lacked cCD3 expression. The 2 cases with classic NK-cell immunophenotype but partial cCD3 expression showed no molecular genetic features of T-cell lineage by TCR gene rearrangement studies. Conclusions Uniform cCD3 positivity and homogeneous cCD3 negativity highly suggest T-cell and NK lineage, respectively. When partial cCD3 expression is encountered, additional confirmatory studies should be pursued for the most accurate lineage assignment.

AbstractCWP232291 (CWP291) is a small-molecule inhibitor of Wnt signaling that causes degradation of β-catenin via apoptosis induction through endoplasmic reticulum stress activation. This first-in-human, open-label, dose-escalation study to evaluate the safety, maximum tolerated dose (MTD), and preliminary efficacy of CWP291 enrolled 69 patients with hematologic malignancies (acute myeloid leukemia [AML], n = 64; myelodysplastic syndrome, n = 5) in 15 dose-escalation cohorts of 4 to 334 mg/m2 using a modified 3+3 design and 1 dose-expansion cohort. CWP291 was administered IV daily for 7 days every 21 days. The most common treatment-emergent adverse events (TEAEs) were nausea (n = 44, 64%), vomiting (n = 32, 46%), diarrhea (n = 25, 36%), and infusion-related reactions (n = 20, 29%). Grade ≥3 TEAEs in &gt;3 patients (5%) were pneumonia (n = 8, 12%); hypophosphatemia (n = 6, 8%); leukocytosis, nausea, cellulitis, sepsis, and hypokalemia (n = 5 each, 7% each); and hypertension (n = 4, 6%). Dose-limiting toxicities included nausea (n = 3) and abdominal pain, anaphylactic reaction, myalgia, and rash (n = 1, each); the MTD was defined at 257 mg/m2. CWP232204, the active metabolite of CWP291, showed pharmacokinetic linearity on both days 1 and 7, and a terminal half-life of ∼12 hours. Among 54 response-evaluable AML patients, there was one complete response at a dose of 153 mg/m2 and one partial response at 198 mg/m2; bone marrow blast percentage reduced from a median of 58.3% to 3.5% and 15.0% to 4.2%, respectively. Future studies will explore CWP291, with a mechanism of action aimed at eradication of earlier progenitors via Wnt pathway blockade, as combination therapy. This trial was registered at www.clinicaltrials.gov as #NCT01398462.

Abstract Background Flow cytometric detection of T‐cell clonality is challenging. The current available methodology for T‐cell receptor (TCR) Vβ repertoire evaluation is a complex assay and has limited sensitivity especially for detecting low levels of disease. Therefore, there is an unmet need for a reliable, simple, and rapid assay to identify T‐cell clonality. The rearrangement of the TCRB gene involves the random and mutually exclusive expression of one of two constant β chain genes (TRBC1 and TRBC2), analogous to the kappa and lambda gene utilization by B cells. Methods Here, we used a single TRBC1 antibody, in conjunction with other T‐cell associated markers, to detect T‐cell clonality in tissue biopsies and body fluids. A total of 143 tissue/body fluid specimens from 46 patients with a definitive diagnosis of a T‐cell neoplasm and 97 patients with no T‐cell malignancy were analyzed with a cocktail of monoclonal antibodies including CD2/CD3/CD4/CD5/CD7/CD8/CD45/TCRγδ/TRBC1. Results We examined TRBC1 expression on neoplastic T‐cell populations identified based on their immunophenotypic aberrancies, and monotypic TRBC1 expression was identified in all 46 known T‐cell lymphoma cases. We applied a similar gating strategy to the 97 cases without T‐cell neoplasms, and arbitrarily dissected T‐cell populations into immunophenotypically distinct subsets; in this group, we found that all cases revealed an expected polytypic TRBC1 expression in all subsets. Conclusions Single TRBC1 antibody detection of T‐cell clonality by flow cytometry is a simple, rapid, and robust assay that could be routinely utilized in flow cytometric laboratories.

Abstract Background: The combination of cediranib (ced) and olaparib (olap) improves progression-free survival and overall response rates (ORR) in women with recurrent plat sensitive high-grade serous (HGS) ovarian cancer compared to olap alone. In this Phase 2 study of ced/olap in women with relapsed ovarian cancer (NCT02345265), we observed an ORR of 74% with ced/olap in plat sensitive relapsed patients (pts) and an ORR of 20% in plat resistant pts. BROCA-HR was performed to characterize tumor HRD status and to correlate this with the activity of ced/olap in the plat sensitive and resistant settings. Methods: Pts with relapsed ovarian cancer across 11 centers were enrolled to 2 cohorts, either plat sensitive or resistant. All pts received ced 30mg daily and olap tablets 200mg BID. Archival, pre-treatment, and on-treatment biopsies were collected on all pts where safely feasible; pts also had the option of undergoing a post-progression biopsy. A baseline blood sample was collected for germline testing and matched control. Available samples were sequenced with BROCA-HR, and HRD status was determined by (1) presence of an HR-related mutation or (2) an increase in loss of heterozygosity (LOH) score. Results: 72 pts were enrolled, with 70 pts receiving study treatment (35 plat sensitive and 35 plat resistant). BROCA-HR analysis is complete on 60 samples, with 10 samples in final analysis. The concordance of HRD status by presence of an HR-related mutation or by LOH score was relatively low (agreement=36/60=60%, Cohen's Kappa=0.28). In 19 pts with a germline BRCA mutation, 16 were HRD+ by LOH (LOH high), 2 were HRD- by LOH (LOH low), and 1 not quantifiable. 3 pts had a somatic BRCA mutation; 1 was LOH high, 1 LOH low, and 1 not quantifiable. 4 pts had non-BRCA somatic HR-related mutations (3 CDK12; 1 ATR); 3 were LOH high and 1 LOH low. Of the 34 pts without HR-related mutations, 15 were LOH high, 16 were LOH low, and 3 not quantifiable. In 29 plat sensitive pts with BROCA-HR results, 18 were HRD+ by mutation (12 germline BRCA, 3 somatic BRCA, 3 somatic other), and 16 were HRD+ by LOH (LOH high). The ORR in plat sensitive pts by HRD status with available HRD results was: 22/29=75.9% (13/18=72% HRDmut+; 9/11=82% HRDmut-); (12/16=75% LOH high; 6/9= 67% LOH low). In 31 plat resistant pts with BROCA-HR results, 8 were HRD+ by mutation (7 germline BRCA, 0 somatic BRCA, 1 somatic other), and 19 were HRD+ by LOH. The ORR in plat resistant pts by HRD status with available HRD results was: 7/31=22.6% (4/8=50% HRDmut+; 3/23=13% HRDmut-, P=0.05); (7/19=37% LOH high; 0/11= 0% LOH low, P=0.03). Updated results with the full data set are pending. Conclusion: Ced/olap has clinical activity in women with relapsed ovarian cancer, both in the plat sensitive and plat resistant settings. In women with plat sensitive disease, where response rates are high, HRD status by presence of an HR-related mutation or LOH status does not appear to provide significant additional information regarding likelihood of response. In women with plat resistant disease, the presence of HRD by an HR-related mutation or LOH status is correlated with a higher likelihood of response. Citation Format: Joyce F Liu, Su-Chun Cheng, Robert M Wenham, Andrea E Wahner Hendrickson, Deborah K Armstrong, Nancy Chan, David E Cohn, Jung-Min Lee, Richard T Penson, Mihaela Cristea, James Abbruzzese, Koji Matsuo, Alexander B Olawaiye, Jennifer Curtis, Geoffrey Shapiro, Ursula A Matulonis, Elise Kohn, Percy Ivy, Elizabeth M Swisher. Correlation of homologous recombination deficiency (HRD) status by BROCA-HR sequencing with response to combination cediranib and olaparib in relapsed ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A074. doi:10.1158/1535-7163.TARG-19-A074