Phase II study of PEGPH20 plus pembrolizumab for patients (pts) with hyaluronan (HA)-high refractory metastatic pancreatic adenocarcinoma (mPC): PCRT16-001

576

Background: Stromal HA poses a physical barrier and protects tumor cells from immune surveillance. PEGPH20 is a pegylated, human recombinant PH20 hyaluronidase that remodels tumor stroma. Preclinical studies of PEGPH20 showed improved infiltration of cytotoxic T-lymphocytes and delivery of chemotherapy and PD1/PD-L1 antibodies. This study aimed to evaluate the efficacy, safety, and translational biomarkers of PEGPH20 plus pembrolizumab in pts with HA-high refractory mPC. Methods: mPC pts with HA-high expression, ECOG PS 0-1, ≤ 2 prior therapies for metastatic disease, life expectancy ≥ 12 weeks were treated with PEGPH20 3 µg/kg iv on D1, D8, D15 and pembrolizumab 200 mg iv on D1 in 21-day cycles. Primary endpoint was progression-free survival (PFS). Secondary endpoints were safety, overall survival (OS), and objective response rate (ORR). Blood and tumor biopsies were collected at baseline and on-study. Translational endpoints included flow cytometry and IHC for immune subsets, T-cell receptor sequencing, immune transcriptome, circulating cytokines, and plasma and tumor HA levels. Assuming a one-sided α-level of 0.05 and power of 80%, 31 evaluable pts were needed to detect an improvement of median PFS from 3 to 6 months. Results: Between May 2019 to Nov 2019, 38 pts were screened for HA expression, and 8 pts were enrolled, with median age 68 years (range 60-73), 7 males, and median 2 prior therapies (range 1-4). The accrual was stopped early by Halozyme Pharmaceuticals due to lack of benefit from PEGPH20 added to chemotherapy in the HALO-301 study. Treatment exposure median was 2 cycles (range 1-6). Reasons for study discontinuation were disease progression (n = 4), termination by sponsor (n = 3), patient withdrawal to enroll in hospice (n = 1). Treatment related toxicities were musculoskeletal (n = 6, grade 1/2), edema (n = 2, grade 1), fatigue (n = 1, grade 3), dyspnea (n = 1, grade 2), hypothyroidism (n = 1, grade 2). Median OS was 7.2 months (95% CI 1.2-11.8), and median PFS was 1.5 months (95% CI 0.9-4.4). Best response was stable disease (n = 2, 25%) lasting 2.2 and 9 months, respectively, and no responses were noted. Patients with available molecular sequencing data had MSS tumors. Translational biomarkers will be presented. Conclusions: Pembrolizumab and PEGPH20 did not increase PFS compared to historical data among heavily pretreated mPC pts, but the median OS of 7.2 months is encouraging. Translational analyses will provide insights into immune modulatory effects from PEGPH20 that could inform future studies with stroma targeted therapies and immune checkpoint blockade in mPC. Clinical trial information: NCT03634332.

Detection of germline variants using expanded multigene panels in patients with localized pancreatic cancer

BACKGROUND

Current guidelines recommend genetic testing for all patients with pancreatic cancer (PC).

METHODS

Patients with localized PC who received neoadjuvant therapy between 2009 and 2018 were identified. Genetic consultation (including personal and family history of cancer), genetic testing, and variant data were abstracted.

RESULTS

Of 510 patients identified, 163 (32%) underwent genetic counseling and genetic testing was performed in 127 (25%). Patients who underwent genetic testing were younger (median age: 63 vs. 67, p = 0.01). Multi-gene testing was performed in 114 (90%) of 127 patients, targeted gene testing was performed in 8 (6%), and not specified in 5 (4%). Of 127 patients who underwent genetic testing, 20 (16%) had pathogenic (P)/likely pathogenic (LP) variants, observed in ATM (n = 7/105,7%), CHEK2 (n = 3/98, 3%), BRCA1 (n = 2/117, 2%), BRCA2 (n = 2/122, 2%), PALB2 (n = 1/115, 1%), MUTYH (n = 1/98, 1%), CDKN2A (n = 1/94, 1%), STK11 (n = 1/97, 1%), NBN (n = 1/98, 1%), and MSH6 (n = 1/97, 1%). Of 20 patients with either a P/LP variant, nine (45%) had a prior cancer, three (15%) had a first-degree relative with PC, and six (30%) had an any-degree relative with PC.

CONCLUSION

Pathogenic/likely pathogenic variants were identified in 16% of patients who underwent genetic testing, 60% of which occurred in the homologous recombination pathway.

Prognostic effect of specific RAS/BRAF mutations in patients (pts) with metastatic colorectal cancer (mCRC)

4050

Background: Somatic mutations in KRAS, HRAS, NRAS (extended RAS) and BRAF have prognostic and predictive impact in pts with mCRC. We analyzed the prognostic impact of specific somatic mutations in extended RAS and BRAF. Methods: We retrospectively reviewed the electronic medical records of pts with mCRC at our institution who underwent comprehensive genomic profiling (CGP) utilizing the Foundation One assay. DNA was extracted from clinical specimens and CGP was performed on hybrid-capture, adaptor ligation-based libraries for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. BRAF mutations were classified as class I, II and III according to accepted nomenclature. Fisher’s exact test and Kaplan Meier estimates were used for statistical analyses. This project was approved by the Medical College of Wisconsin Institutional Review Board. Results: 273 pts were identified - median age at diagnosis was 57, 48% were male. Somatic mutations in extended RAS were found in 138 (50%) pts, majority being mutations in KRAS (46%). Among pts with KRAS mutations, codon 12, 13, 61 and 146 mutations accounted for 73%, 11%, 4% and 6% respectively while KRAS G12C mutations accounted for 9%. BRAF mutations were detected in 22 (8%) pts - BRAF V600E and non–V600E mutations accounting for 4.4% and 3.6% respectively. Among pts with BRAF mutations, 17 (77%) were kinase domain mutations, 16 of which could be further classified as class I (12/16), II (1/16) and III (3/16). Median overall survival (mOS) for the entire cohort was 26.4 months (mo). KRAS mutated pts had a mOS of 25.8 mo; pts with KRAS G12C mutation had a mOS of 23 mo compared to 27.1 mo for pts with other KRAS mutations (p < 0.001).Pts with BRAF mutation had a mOS of 26.2 mo; pts with BRAF V600E mutation had a mOS of 14.1 mo compared to 30.6 mo for pts with BRAF non-V600E mutations (p = 0.1). Conclusions: The poor prognosis of pts with KRAS G12C and BRAF V600E mutations compared to pts with other KRAS and BRAF mutations merit further biologic characterization with functional assays. Individualized therapeutic strategies must be conceptualized for mCRC pts with specific RAS/BRAF mutations, considering their widely disparate prognosis and putative downstream signaling mechanisms. Dynamic molecular simulation to understand conformational changes in proteins associated with specific mutations will be pivotal to optimizing precision therapeutic strategies.

Impact of tumor histology and socioeconomic factors on survival of patients suffering from malignant vascular tumors of liver and hepatocellular carcinomas: A SEER database analysis

e16612

Background: Primary malignant vascular tumors of the liver are rare, aggressive and poorly understood subtypes of liver cancers. In this analysis, we aim to determine the impact of tumor histology and other socio economic factors on survival of these tumors and hepatocellular carcinomas. Methods: Patients with malignant histopathological diagnoses of hepatocellular carcinoma not otherwise specified (HCC NOS), hepatocellular carcinoma with spindle cell (HCC SP), fibrolamellar (HCC F), clear cell (HCC CL), scirrhous (HCC SC) and pleomorphic variants ( HCC PL), combined hepatocellular carcinoma and cholangiocarcinoma (Mixed), hepatic angiosarcoma (AS), hemangioendothelioma (HE), its epithelioid variant (EHE) and hemangiopericytoma (HP) were identified using the SEER (version 2018) database. Overall survival was studied with Kaplan–Meier with the log rank method. Multivariable analysis was performed to assess the impact of race, ethnicity, marital and insurance status on survival of these patients. Results: We analyzed de-identified data of 104502 patients from the year 1973 to 2016 with hepatocellular carcinomas and malignant vascular tumors of liver (including 101851 patients with HCCNOS, 70 with HCC SP, 378 with HCC F, 104 with HCC SC, 593 with HCC CL, 23 with HCC PL, 950 with Mixed, 367 with AS, 36 with HE, 120 with EHE and 10 with HP ) respectively. Median overall survival (OS) of HCC NOS was calculated to be 7 months. Among hepatocellular carcinoma patients HCC F had the longest median OS of 29 months and HCC SP had the shortest median OS of 3months (P < 0.001). Additionally, among patients with malignant vascular tumors, AS had the shortest median OS (1 month) while patients with EHE had the longest median OS of 81 months (P < 0.001). Overall, married and insured patients had a better overall survival than unmarried and uninsured patients (P < 0.04). Conclusions: Malignant vascular tumors of liver are rare in comparison to hepatocellular carcinomas. Spindle cell variant of HCC and liver angiosarcomas carry the worst prognosis and fibrolamellar variant of HCC, hemangioendothelioma (HE) and its epithelioid variant (EHE) have the best prognosis. Insurance and marital status has a positive impact on overall survival of liver cancer patients.

Value of Pretreatment 18F-fluorodeoxyglucose Positron Emission Tomography in Patients With Localized Pancreatic Cancer Treated With Neoadjuvant Therapy

Background:¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging is not routine in patients with localized pancreatic cancer (PC). We evaluated the prognostic value of PET/CT in patients who received neoadjuvant therapy.

Methods: Patients with localized PC underwent pretreatment PET/CT with or without posttreatment (preop) PET/CT. Maximum standardized uptake values (SUV) were classified as high or low based on a cut point of 7.5 at diagnosis (SUV_dx) and 3.5 after neoadjuvant therapy (preoperative; SUV_preop). Preop carbohydrate antigen 19-9 (CA19-9) was classified as normal ( ≤ 35 U/mL) or elevated.

Results: Pretreatment PET/CT imaging was performed on 201 consecutive patients; SUV_dx was high in 98 (49%) and low in 103 (51%). Preop PET/CT was available in 104 (52%) of the 201 patients; SUV_preop was high in 60 (58%) and low in 44 (42%). Following neoadjuvant therapy, preop CA19-9 was normal in 90 (45%) patients and elevated in 111 (55%). Median overall survival (OS) of all patients was 27 months; 33 months for the 103 patients with a low SUV_dx and 22 months for the 98 patients with a high SUV_dx (p = 0.03). Median OS for patients with low SUV_dx/normal preop CA19-9, high SUV_dx/normal preop CA19-9, low SUV_dx/elevated preop CA19-9, and high SUV_dx/elevated preop CA19-9 were 66, 34, 23, and 17 months, respectively (p < 0.0001). OS was 44 months for the 148 (74%) patients who completed all intended neoadjuvant therapy and surgery and 13 months for the 53 (26%) who did not undergo surgery (p < 0.001).

Conclusion: Pretreatment PET/CT avidity and preop CA19-9 are clinically significant prognostic markers in patients with PC.

Impact of Neoadjuvant Chemoradiation on Pathologic Response in Patients With Localized Pancreatic Cancer

Introduction/Background: Multimodal neoadjuvant therapy has resulted in increased rates of histologic response in pancreatic tumors and adjacent lymph nodes. The biologic significance of the collective response in the primary tumor and lymph nodes is not understood.

Methods: Patients with localized PC who received neoadjuvant therapy and surgery with histologic assessment of the primary tumor and local-regional lymph nodes were included. Histopathologic response was classified using the modified Ryan score as follows: no viable cancer cells (CR), rare groups of cancer cells (nCR), residual cancer with evident tumor regression (PR), and extensive residual cancer with no evident tumor regression (NR). Nodal status was defined by number of lymph nodes (LN) with tumor metastases: N0 (0 LN), N1 (1–3), N2 (≥4).

Results: Of 341 patients with localized PC who received neoadjuvant therapy and surgery, 107 (31%) received chemoradiation alone, 44 (13%) received chemotherapy alone, and 190 (56%) received chemotherapy and chemoradiation. Histopathologic response consisted of 15 (4%) CRs, 59 (17%) nCRs, 188 (55%) PRs, and 79 (23%) NRs. Patients who received chemotherapy alone had the worst responses (n = 21 for NR, 48%) as compared to patients who received chemoradiation alone (n = 25 for NR, 24%) or patients who received both therapies (n = 33 for NR, 17%) (Table 1; p = 0.001). Median overall survival for all 341 patients was 39 months; OS by histopathologic subtype was not reached (CR), 49 months (nCR), 38 months (PR), and 34 months (NR), respectively (p = 0.004). Of the 341 patients, 208 (61%) had N0 disease, 97 (28%) had N1 disease, and 36 (11%) had N2 disease. In an adjusted hazards model, modified Ryan score of PR or NR (HR: 1.71; 95% CI: 1.15–2.54; p = 0.008) and N1 (HR: 1.42; 95% CI: 1.1.02–2.01; p = 0.04), or N2 disease (HR: 2.54, 95% CI: 1.64–3.93; p < 0.001) were associated with increased risk of death.

Conclusions: Neoadjuvant chemotherapy alone is associated with lower rates of pathologic response. Patients with CR or nCR have a significantly improved OS as compared to patients with PR or NR. Nodal status is the most important pathologic prognostic factor. Neoadjuvant chemoradiation may be an important driver of pathologic response.

Impact of CDKN2A/b status in pancreatic cancer (PC)

759

Background: PC is a lethal disease with limited treatment options. We utilized Comprehensive Genomic Profiling (CGP) to identify putative prognostic and/or predictive biomarkers. Methods: We retrospectively reviewed PC patients (pts) at our institution who underwent CGP utilizing the Foundation One assay. CGP was performed on hybrid-capture, adaptor ligation-based libraries for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. PC pts were categorized by clinical stage – localized (resectable and borderline resectable PC; LPC), locally advanced (LAPC) and metastatic (mPC). Effect of gene alterations (GAs) with at least 10% prevalence were analyzed. The marginal effect of each gene on radiographic response and survival outcomes was estimated using proportional odds and multivariate Cox regression analysis, respectively, adjusting for stage. Results: Ninety-three pts were identified - median age was 63, 55% were male, and 50% were smokers. Clinical stage at diagnosis was LPC, LAPC and mPC in 42 (45%), 23 (25%) and 28 (30%) pts, respectively. The most commonly altered genes were KRAS (94%), TP53 (75%), CDKN2A (41.2%) and SMAD4 (32.9%). All patients were microsatellite stable and the median tumor mutational burden was 1.7. 5-FU (52%) or Gemcitabine (46%) based chemotherapy combinations were utilized as the first systemic therapy. Median overall survival for patients with LPC, LAPC and mPC were 30.7, 28.8 and 9.6 months respectively. Thirty-eight (91%) pts with LPC underwent curative intent surgery compared to 15 (65%) pts with LAPC (p = 0.019). Thirty-five (95%) pts with wild type (WT) CDKN2A and 47 (94%) pts with WT CDKN2B underwent curative intent surgery compared to 13 (65%) and 1(14%) pt(s) with GAs in CDKN2A and CDKN2B respectively (p = 0.003 and p < 0.0001 respectively). The response to chemotherapy was statistically significantly higher in pts with WT CDKN2A (53%) and CDKN2B (48%) compared to pts with GAs in CDKN2A (19%) and CDKN2B (12%) (p = 0.03 and p = 0.05, respectively). Conclusions: GAs in CDKN2A/B may have a predictive and possibly a prognostic impact. The clinical validity and biological relevance of these findings need to be further explored in larger studies.

Phase II trial of BPM31510-IV plus gemcitabine in advanced pancreatic ductal adenocarcinomas (PDAC)

723

Background: BPM31510-IV is an Ubidecarenone (CoQ10) drug-lipid conjugate nanodispersion targeting metabolic machinery in cancer, shifting bioenergetics from lactate dependency towards mitochondrial OxPhos to generate ROS and activate apoptosis. An MTD of BPM31510-IV in combination with gemcitabine was established at 110mg/kg in a Phase I clinical trial, which determined the dose for the Phase 2 investigation. Methods: Eligible patients (aged ≥ 18 y) with relapsed/refractory PDAC to standard treatment (ST) and met inclusion/exclusion criteria were recruited. Patients received 110mg/kg IV BPM31510 in combination with gemcitabine in a 144-hour infusion. Tumor response was evaluated at week 10 and then every 8 weeks. Study endpoints assessed were Overall Response Rate (ORR), Overall Survival (OS), Progression-Free Survival (PFS), Time to Progression (TTP), Tumor Response using Adaptive Molecular Responses (multi-omic molecular profiling), changes in CA 19-9 levels and patient reported Quality of Life (QOL) using the validated FACT-HEP PRO. A comprehensive multi-omic profiling for identification of biomarkers for patient stratification was explored. Results: Of the 35 patients enrolled to receive therapy, 18 patients met criteria of an adequately treated cohort (ATC- received BPM31510-IV + gemcitabine for 30 days over 2 cycles and had a RECIST 1.1 evaluation) while remaining (n = 17) had progressive disease (PD). Half of the ATC population (n = 9/18, 50%) achieved best ORR of stable disease (SD); 10/18 (55 %) demonstrated SD as best response at target lesions and 8/18 demonstrated SD at end of Cycle 2. The mTTP was 121 days (70 – 147, 95% CI); PFS 118 days (70 – 131, 95% CI) and OS 218 days (131 – 228, 95% CI), respectively. Overall, BPM31510-IV was well tolerated; the most common AE’s were GI related. Conclusions: The efficacy signal observed in this heavily pretreated population in addition to the toxicity profile warrants further clinical investigation of BPM31510-IV + gemcitabine in advanced PDAC. Clinical trial information: NCT02650804 . [Table: see text]

Utilization of somatic comprehensive genomic profiling (CGP) to identify patients (pts) with pancreatic cancer (PC) that harbor germline DNA damage repair (DDR) gene alterations

760

Background: Somatic and germline DDR gene alterations in PC have been postulated to positively predict response to DNA damaging cytotoxic agents. Due to the relatively high prevalence of germline DDR gene alterations, germline testing is recommended in all pts with PC. We examined whether somatic CGP can be used to reliably identify PC pts that merit germline testing. Methods: We retrospectively reviewed the electronic medical records of PC pts who underwent both somatic CGP (utilizing the Foundation One assay) and germline testing. DDR gene mutations were categorized as somatic-pathogenic, somatic-variant of uncertain significance (VUS), germline-pathogenic and germline-VUS. For somatic testing, DNA was extracted from formalin fixed paraffin embedded (FFPE) clinical specimens and CGP was done on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. Germline genetic testing was performed on submitted blood or saliva samples, utilizing commercial assays; next generation or Sanger sequencing of all coding regions and adjacent intronic nucleotides were performed. Results: Ninety-three pts had somatic CGP data, 51 (55%) pts had both somatic CGP and germline data available. Among the 51 pts with both germline and somatic data available, DDR gene alterations that were somatic-pathogenic, germline-pathogenic, somatic-VUS and germline-VUS were present in 7 (13.7%), 7 (13.7%), 23 (45.1%) and 16 (31.4%) pts, respectively. Of the 7 pts with somatic-pathogenic alterations, 5 (71%) had a concordant germline alteration and of the 7 pts with germline-pathogenic alterations, 5 (71%) had a concordant somatic alteration. Of the 23 pts with somatic-VUSs, 12 (52%) had a concordant germline VUS and of the 16 pts with germline-VUSs, 12 (75%) had a concordant somatic VUS. Conclusions: Both somatic and germline DDR gene alterations are common in PC pts. Despite the relatively high concordance rate between somatic and germline pathogenic DDR gene alterations, somatic CGP will miss approximately one fourth of the germline DDR gene alterations.

Role of Molecular Profiling of Pancreatic Cancer After Neoadjuvant Therapy: Does it Change Practice?

INTRODUCTION

Tumor profiling can improve the selection of oncologic therapies in patients with pancreatic cancer (PC). The impact of neoadjuvant therapy on tumor testing is unknown.

METHODS

Molecular profiling using commercially available 53-, 315-, or 472-gene next generation sequencing (NGS) panels was performed on surgical specimens following neoadjuvant therapy. All specimens with 472-gene sequencing also had immunohistochemical (IHC) testing. Treatment recommendations were based on somatic variants and IHC staining.

RESULTS

NGS was performed on 74 patient specimens: 42 (57%) with a 472-gene panel, 28 (38%) with a 315-gene panel, 3 (4%) had 472- and 315-gene panels, and 1 (1%) patient had 53- and 472-gene panels (78 total tests). Likely pathogenic/pathogenic variants were identified in 73 (94%) of the 78 tests. Of the 73 samples with variants identified, 13 (18%) variants were associated with an actionable treatment: ATM (n = 10), BRCA1 (n = 1), PIK3CA (n = 1), and BRCA2 (n = 1). No patient had more than one actionable variant. Based on NGS results, the most commonly recommended therapy was a platinum agent (n = 12/78, 15%). Of the 46 specimens that underwent IHC analysis, overlapping chemotherapeutic treatment recommendations were identified in 40 (87%) specimens.

CONCLUSION

Using current multigene NGS panels, actionable variants were identified in 13 (18%) of 74 surgical specimens and primarily involved genes of the DNA repair pathway. Anecdotal reproducibility of test concordance was low.

PCRT16-001: Phase II study of PEGPH20 plus pembrolizumab for patients (pts) with hyaluronan (HA)-high refractory metastatic pancreatic ductal adenocarcinoma (mPDA)

TPS785

Background: PDA is characterized by invasiveness and therapeutic resistance in part due to a desmoplastic stroma and an immunosuppressive microenvironment ( Provenzano PP, Hingorani S. Br J Cancer 2013). PD1/PD-L1 inhibitors have no single agent activity in PDA, except for pts with mismatch repair defects. There is high need to overcome resistance to immune targeted therapies and develop biomarkers for pts selection. Stromal HA poses a physical barrier and protects tumor cells from immune surveillance ( Kultti A, et al Biomed Res Int 2014). By remodeling the tumor stroma, PEGPH20 allows infiltration of cytotoxic T lymphocytes, and improves delivery of chemotherapy and PD1/PD-L1 antibodies ( Singha NC, et al Mol Cancer Ther 2015). mPDA pts refractory to 1st line therapy have median overall survival (OS) of 6 mos. We hypothesize that stroma remodeling with PEGPH20 sensitizes PDA to immune therapy, and stroma and immunologic biomarkers will identify pts most likely to benefit. In this trial we will evaluate the efficacy, safety and translational biomarkers of PEGPH20 plus pembrolizumab in HA-high refractory mPDA. Methods: Eligible pts have ECOG PS 0-1, ≤ 2 prior therapies for mPDA, life expectancy ≥ 12 wks, able/willing to have tumor biopsies at baseline and after 6 wks of treatment. PEGPH20 dosing is 3 µg/kg iv QW and pembrolizumab 200 mg iv Q3W (2-4 hrs after PEGPH20 on wk 1) in 3-wk cycles. All pts receive prophylactic low molecular weight heparin. Primary endpoint: progression-free survival (PFS). Secondary endpoints: safety, OS, response rates. Translational endpoints: flow cytometry of peripheral and intratumoral immune cells, T-cell receptor sequencing, immune transcriptome, immune subsets IHC, circulating cytokines, serial plasma and tumor HA levels. For the primary endpoint of PFS, with a sample size of 31 evaluable pts, a one-sided α-level of 0.05, assuming 12 mos of accrual and 6 mos of follow-up, this study has 80% power to detect a difference between the null hypothesis median PFS 3 mos, versus the alternative hypothesis median PFS 6 mos. The study was activated in May 2019 and is open to accrual; 6 pts were enrolled as of 24Sept 2019. Clinical trial information: NCT03634332.

Abstract 4931: Not all tumors are created equal: Evaluating the impact of comprehensive genomic profiling (CGP) on clinical outcomes in esophageal/gastroesophageal cancer (GEJ CA)

Introduction:

Systemic chemotherapy plays a pivotal role in the treatment of localized and metastatic GEJ CA patients (pts), however, there are no reliable predictive biomarkers. CGP is increasingly used to guide selection of targeted therapies, but its role in personalizing cytotoxic chemotherapy is not clear. We investigated the correlation between somatic alterations (SAs) and clinical outcome in pts with GEJ CA treated with cytotoxic chemotherapy.

Methods:

Medical records of all patients with GEJ CA who had CGP data available were retrospectively reviewed under an IRB approved protocol. DNA was extracted from formalin fixed paraffin embedded clinical specimens and CGP was performed on hybrid-capture, adaptor ligation-based libraries to a mean coverage depth of &gt;600 unique reads utilizing the Foundation Medicine platform (315 gene panel). The effect of the SAs and clinical covariates on response and survival outcomes were modeled using logistic and Cox regression analyses, respectively. Lasso was used for model selection, with the penalty parameter chosen as providing the lowest error-rate via 5-fold cross-validation.

Results:

Fifty-six patients were identified; median age was 62.5, 51(91%) were male, 39 (70%) had metastatic disease, histology was adenocarcinoma in 41 (73%) and ERBB2 amplification was detected in 11 pts (22%). Median tumor mutational burden (TMB) was 6.1 (0.9-75.7) and one patient had a microsatellite unstable tumor. 46 (82%) pts received a platinum-based combination as first line therapy, mfolfox6 was the most commonly utilized regimen (30%). Complete Response (CR), Partial Response (PR), Stable Disease (SD), and Progressive Disease (PD) were noted in 3 (5.6%), 34 (63.0%), 5 (9.3%) and 12 (22.2%) pts, respectively. Median progression free survival (PFS) and OS was 31.3 and 72.8 months, respectively for patients with localized GEJ CA, while median PFS and OS were 6.3 and 18.7 months, respectively for patients with metastatic GEJ CA. On multivariate analysis, in addition to stage, SA in SPTA1 correlated with improved response (p=0.0026, OR=0.052, 95% CI 0.002-0.378), while SAs in PIK3CG (p = 0.016; HR=-6.7, 95% CI 1.26-30.46) and EGFR (p = 0.041; HR=3.6; 95% CI 0.9-11.8) correlated with worse overall survival (OS).

Conclusion:

We were able to identify SAs that correlated with objective response and survival, however, confirmatory analyses in larger datasets and prospective validation is necessary. The negative prognostic effect of SAs in PIK3CG and EGFR merit further exploration, considering their viability as therapeutic targets. Robust, quantitative and systematic somatic analysis of pre-treatment biopsies, pathway-network analysis and correlation with clinical outcome are essential to gaining mechanistic insights and maximizing therapeutic impact.

Citation Format: Vidya Kollu, Arun Singhavi, Paul S. Ritch, James P. Thomas, Aniko Szabo, Ben George. Not all tumors are created equal: Evaluating the impact of comprehensive genomic profiling (CGP) on clinical outcomes in esophageal/gastroesophageal cancer (GEJ CA) [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 4931.

A randomized, phase II clinical trial of preoperative stereotactic body radiation therapy versus conventionally fractionated chemoradiation for resectable, borderline-resectable, or locally advanced type a pancreatic adenocarcinoma

TPS4167

Background: There is growing consensus for the use of neoadjuvant therapy in patients with potentially operable pancreatic adenocarcinoma (PC). However, there is not consensus on the type and duration of chemotherapy or radiation therapy (RT) dose. Stereotactic body radiation therapy (SBRT) has gained popularity despite the absence of prospective data for its use in the preoperative setting. Furthermore, SBRT preoperatively has not been standardized. At present, there exists no randomized data comparing preoperative SBRT with conventionally fractionated concurrent chemo-RT. We designed this trial to examine differences between pre-op RT dose and fractionation schedules. Methods: This study is a prospective, randomized, two-arm, phase II clinical trial. Eligible patients must have cytologically confirmed PC and be deemed suitable for surgical resection with resectable, borderline resectable, or locally advanced type A disease, based on cross-sectional imaging. Before randomization patients are stratified by clinical node positivity, neoadjuvant chemotherapy, and stage of disease. Patients are then randomized to either 50.4 Gy over 28 fractions with concurrent weekly Gemcitabine vs SBRT to a total dose of 25-35 Gy over 5 fractions. The primary endpoint of the study is pathologic node positivity. We hypothesize that patients treated with neoadjuvant chemotherapy followed by conventionally fractionated chemo-RT will have a lower rate of pathologic node positivity as compared to those patients treated with neoadjuvant chemotherapy followed by SBRT. Secondary endpoints include patient reported quality of life, local recurrence, primary tumor pathologic response, margin status, surgical complications, MR based treatment response, and overall survival. We anticipate a node positivity rate of 37% when using preoperative chemotherapy followed by SBRT. We hypothesize that treatment with chemotherapy followed by conventionally fractionated chemo-RT will reduce the rate of node positivity to 17%. Using a one-sided Type I error rate of 0.1, approximately 88 total patients (44 per arm) provide an 80% power to detect the hypothesized difference in pathologic node positivity between the two arms. To address patient dropout, an additional 14 patients (about 15%) will be enrolled for a total target accrual of 102 patients. The trial opened in November 2018 and 8 of the planned 102 patients have been enrolled. Clinical trial information: NCT03704662.

Costs of care with liver directed therapy (LDT) and sorafenib (S) in patients (pts) with hepatocellular carcinoma (HCC)

383

Background: 80% of HCC pts present with advanced disease, treatment for such pts is palliative in nature. It is important to ascertain cost associated with such palliative therapy, considering modest survival benefit afforded by these treatments. Methods: Utilizing a non-Medicare national claims database (MarketScan), we analyzed a cohort of pts with HCC diagnosis (Dx). Consistent with literature, pts selected had at least two claims with HCC code (155.0) between 1/1/2010 and 12/31/2013, at least 2 claims with chronic liver condition within 1 year of the HCC Dx, no claims for other malignancies for 1 year before HCC Dx, and excluded hepatectomy or transplant. Follow up was from date of first HCC claim to end of continuous insurance coverage (EOC) with prescription drug claim tracking, or 12/31/2015. Pts were divided into 4 groups based on receipt of S, LDT, combined therapy (LDT+S), or best supportive care (BSC) after HCC Dx. Costs obtained by adding payment (Pmt) amounts for all inpatient, outpatient, and drug claims over follow-up period. Demographics and costs were summarized using means for continuous and frequencies for categorical variables. No adjustment for censoring was done, as no reason available for EOC. Average monthly cost was computed for each pt, and then averaged over pts. Results: Data were available for 6,987 patients over specified period, 67% were males, mean age was 60.2 years. Cost data by therapy received are summarized in the table below. Conclusions: Majority of HCC pts in this database were treated with BSC. Time to EOC tracked was significantly shorter for pts treated with S, compared to other 3 groups. Monthly cost associated with LDT, LDT+S, and S were not substantially different, but higher than cost associated with BSC. Prospectively collected survival, quality of life and cost data are important to ascertain true impact of palliative therapy in pts with advanced HCC. [Table: see text]

Therapeutic relevance of homologous recombination repair (HRR) pathway variants in metastatic colorectal cancer (mCRC)

677

Background: Intact HRR pathway genes play a critical role in repairing double-stranded DNA breaks. Genomic alterations (GA) in several HRR pathway genes have been well characterized, demonstrating prognostic and predictive significance. However, there are many variants of unknown significance (VUS) in the HRR pathway genes that need better characterization. Methods: Patients (pts) with mCRC that harbored VUSs in HRR pathway genes (HRR- VUS; BRCA1/2, ATM, ATR, RAD50, RAD51, PALB2, CHEK1, CHEK2) and treated with front line platinum therapy were identified by review of our institutional molecular data base (MDB) and EMR. Time to 2nd line therapy (TT2L) and Overall Survival (OS) were calculated. DNA was extracted from formalin fixed paraffin embedded clinical specimens and Next Generation Sequencing (NGS) was performed on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 unique reads utilizing the Foundation Medicine NGS platform. Results: Among the 873 pts in our institutional MDB, 96 (11%) had mCRC, 20 (21%) harbored HRR pathway GAs, 15 (16%) were categorized as VUSs. HRR-VUS pts had a median age of 57 at diagnosis, 5 (33%) were male, 3 (20%) were right-sided. Distribution of HRR-VUSs in this cohort is summarized in table 1. All pts with HRR-VUSs were micro-satellite stable (MSS), median TMB was 4.5 (range 0 – 8.1). Median TT2L and OS in mCRC pts with HRR-VUSs were 8.0 and 43 months (m) respectively. Two pts with HRR-VUSs had TT2L > 24 m and OS > 40 m; one of them had a BRCA1P1464A mutation, while the other had a BRCA2 amplification. Conclusions: BRCA2, ATM and BRCA1 were the HRR genes that harbored VUSs most frequently in pts with mCRC. Majority with HRR-VUSs had left sided primaries, were MSS and had low TMB. BRCA1P1464A mutation in the ATM binding domain needs further characterization on account of prolonged TT2L with platinum based chemotherapy. Patients with HRR-VUSs that are predictive of benefit with platinum based chemotherapies could be considered for maintenance therapy with PARP inhibitors [Table: see text]

Comprehensive genomic profiling (CGP) in KRAS wild-type (WT) pancreatic ductal adenocarcinoma (PDAC)

271

Background: Mutations in oncogenic KRAS have been widely accepted as the signature genomic alteration (GA) in sporadic PDAC, but therapeutic efforts aimed at targeting constitutively activated KRAS have been disappointing. We examined somatic GAs in KRAS WT PDAC utilizing a CGP platform to identify actionable targets. Methods: DNA was extracted from formalin fixed paraffin embedded (FFPE) PDAC clinical specimens and CGP was performed on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 unique reads. Alterations in the RAS/ RAF/ MEK pathway genes ( KRAS, NRAS, HRAS, ARF, BRAF, EGFR, MAP2K2, MAP2K1, MAPK1) and DNA Damage Repair (DDR) pathway genes ( BRCA1/2, ATM, ATR, BRIP1, RAD50, RAD51, RAD52, PALB2, CHEK1, CHEK2) were examined. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. TMB was categorized based on mutations(m)/Mbp of DNA - high (H; > 20), Intermediate (I; 8-20) and low (L; < 8). Results: CGP was performed on 3426 PDAC specimens; 1815 (53%) were male, 390 (11.3%) were KRAS WT. GAs in the RAS/ RAF/ MEK pathway were identified in 90.6% of all cases, while 68 (17.4%) KRAS WT cases had one or more GAs in RAS/ RAF/ MEK pathway genes. DDR pathway GAs were identified in 1405 (41%) cases for a total of 2050 GAs, and 180 (46%) KRAS WT cases for a total of 285 GAs. DDR pathway alterations were common in KRAS WT PDAC compared to KRAS mutated PDAC (p = 0.028). Among the 842 (24.6%) cases with available TMB data, 5 (0.6%), 104 (12.3%) and 733 (87.1%) pts had H, I and L, TMB respectively. Among 88 (22.6%) KRAS WT cases with available TMB data, 2 (2.3%), 12 (13.6%) and 74 (84.1%) pts had H, I and L, TMB, respectively. MSI status was available in 2314 (67.5%) cases, 13 (0.6%) were MSI-high (MSI-H); among the KRAS WT cases, 222 (57%) had MSI status available, 3 (1.3%) were MSI-H. Conclusions: MSI-H status and high TMB are rare in PDAC, regardless of KRAS mutation status. GAs in the DDR pathway are relatively common in PDAC and may serve as predictive biomarkers for platinum chemotherapeutic agents and/or PARP inhibitors. Prospective validation of such predictive gene signatures will improve therapeutic efficacy and minimize toxicities.

HALO 110-101: A phase Ib, randomized, open-label study of PEGPH20 (pegvorhyaluronidase alfa) in combination with cisplatin (CIS) + gemcitabine (GEM) (PEGCISGEM) or atezolizumab and CIS + GEM (PEGCISGEMATEZO) in hyaluronan-high subjects with locally advanced or metastatic cholangiocarcinoma and gallbladder cancer

TPS543

Background: Cholangiocarcinoma (CCA) is treated with CIS and GEM (CISGEM), but prognosis is poor. Hyaluronan (HA) accumulation in solid tumors may impede drug and immune cell access. PEGPH20 targets tumors that accumulate HA (HA-high). This study (NCT03267940) plans to enroll 70 subjects to evaluate the safety and activity of PEGPH20 + programmed cell death-ligand 1 (PD-L1) agent atezolizumab, (PEGCISGEMATEZO), & PEGPH20 + CISGEM (PEGCISGEM) in HA-high subjects with CCA and gallbladder cancer. Study will comprise initial run-in and expansion portions. Primary endpoints include incidence of AEs and other laboratory/safety parameters and ORR (RECIST v1.1). Secondary endpoints include PK parameters; DOR, DCR, PFS, and ORR (RECIST v1.1 and immune-modified RECIST); and OS and OS by PD-L1 expression. Methods: ~6 HA-high subjects will be enrolled in PEGCISGEM arm run-in portion and undergo at ≥1 cycle; subsequently, 6 HA-high subjects will enter the PEGCISGEMATEZO arm. Treatment period will be 21-day cycles. In the expansion portion, ~50 HA-high subjects will be enrolled and randomized in a 2:2:1 ratio into PEGCISGEMATEZO, PEGCISGEM, and CISGEM arms. PEGPH20 is planned to be administered at 3.0 μg/kg on Days 1, 8 and 15 of all cycles in both portions. ATEZO will be administered at 1200 mg 1–3 hours after PEGPH20 on Day 1 of each 21-day cycle in the PEGCISGEMATEZO arm in both portions. In the PEGCISGEM & PEGCISGEMATEZO arms, dosing schedule for CISGEM is the same during both portions, with administration of 25 mg/m2 CIS and 1000 mg/m2 GEM on Days 2 and 9 of each cycle. In CISGEM control arm (expansion only), dosing schedule will be on Days 1 and 8 of each cycle. Treatment will continue until death, withdrawal of consent, disease progression, or unacceptable toxicity. Tumor response will be evaluated using RECIST v1.1. AEs will be graded per NCI CTCAE v4.03. Tumor samples will be tested retrospectively for PD-L1 expression. Safety data will be periodically monitored by an independent data monitoring committee. Clinical trial information: NCT03267940.

HALO 202: Randomized Phase II Study of PEGPH20 Plus Nab-Paclitaxel/Gemcitabine Versus Nab-Paclitaxel/Gemcitabine in Patients With Untreated, Metastatic Pancreatic Ductal Adenocarcinoma

Purpose Metastatic pancreatic ductal adenocarcinoma is characterized by excessive hyaluronan (HA) accumulation in the tumor microenvironment, elevating interstitial pressure and impairing perfusion. Preclinical studies demonstrated pegvorhyaluronidase alfa (PEGPH20) degrades HA, thereby increasing drug delivery. Patients and Methods Patients with previously untreated metastatic pancreatic ductal adenocarcinoma were randomly assigned to treatment with PEGPH20 plus nab-paclitaxel/gemcitabine (PAG) or nab-paclitaxel/gemcitabine (AG). Tumor HA levels were measured retrospectively using a novel affinity histochemistry assay. Primary end points were progression-free survival (PFS; overall) and thromboembolic (TE) event rate. Secondary end points included overall survival, PFS by HA level, and objective response rate. An early imbalance in TE events in the PAG arm led to a clinical hold; thereafter, patients with TE events were excluded and enoxaparin prophylaxis was initiated. Results A total of 279 patients were randomly assigned; 246 had HA data; 231 were evaluable for efficacy; 84 (34%) had HA-high tumors (ie, extracellular matrix HA staining ≥ 50% of tumor surface at any intensity). PFS was significantly improved with PAG treatment overall (hazard ratio [HR], 0.73; 95% CI, 0.53 to 1.00; P = .049) and for patients with HA-high tumors (HR, 0.51; 95% CI, 0.26 to 1.00; P = .048). In patients with HA-high tumors (PAG v AG), the objective response rate was 45% versus 31%, and median overall survival was 11.5 versus 8.5 months (HR, 0.96; 95% CI, 0.57 to 1.61). The most common treatment-related grade 3/4 adverse events with significant differences between arms (PAG v AG) included muscle spasms (13% v 1%), neutropenia (29% v 18%), and myalgia (5% v 0%). TE events were comparable after enoxaparin initiation (14% PAG v 10% AG). Conclusion This study met its primary end points of PFS and TE event rate. The largest improvement in PFS was observed in patients with HA-high tumors who received PAG. A similar TE event rate was observed between the treatment groups in stage 2 of the trial.

Is Adjuvant Therapy Necessary for All Patients with Localized Pancreatic Cancer Who Have Received Neoadjuvant Therapy?

BACKGROUND

Among patients with localized pancreatic cancer (PC), the benefit of adjuvant therapy after neoadjuvant therapy and surgery is unknown.

METHODS

Patients with localized PC who completed all intended neoadjuvant therapy and surgery were categorized based on the receipt of adjuvant therapy and by pathologic lymph node status (LN^-/LN⁺).

RESULTS

Data was available from 234 consecutive patients, 121 (52%) with resectable and 113 (48%) with borderline resectable PC. Of the 234 patients, 92 (39%) were LN⁺ and 142 (61%) were LN^-. The median overall survival (OS) for the 234 patients was 39 months, 42.3 months for patients who received any adjuvant therapy and 34.1 months for those who did not (p = 0.29). Of the 92 LN⁺ patients, the median OS with and without adjuvant therapy was 29.5 and 23.2 months, respectively (p = 0.02). Of the142 LN^- patients, the median OS was 45 months with or without adjuvant therapy (p = 0.86). In an adjusted hazard model, additional adjuvant therapy had a significant protective effect among LN⁺ patients (HR 0.39; 95% CI 0.21-0.70; p = 0.002) but not in LN^- patients (HR 0.89; 95% CI 0.53-1.52; p = 0.68).

CONCLUSION

Among patients with localized PC who received neoadjuvant therapy and surgery, the benefit of adjuvant therapy was limited to those with node-positive disease.

Multimodality Therapy in Patients With Borderline Resectable or Locally Advanced Pancreatic Cancer: Importance of Locoregional Therapies for a Systemic Disease

Historically, the clinical staging of pancreatic cancer has centered on the surgical management of the primary tumor, because few effective chemotherapeutic agents were available and long-term survival was only achieved in the context of surgical resection. Such a strategy of complete oncologic surgical care is reasonable when surgery is both the principal therapy and highly effective. However, complex surgery for pancreatic cancer-often performed in older patients after a lengthy period of induction therapy-can be associated with significant morbidity and mortality. The majority of patients with pancreatic cancer present either locally advanced or metastatic disease at the time of diagnosis. In this article, we will discuss the role of multimodality management of patients with borderline resectable and locally advanced pancreatic cancer. Considering that surgery has a modest impact on the natural history of pancreatic cancer in most patients, a neoadjuvant approach to treatment sequencing is favored for patients with borderline resectable pancreatic cancer, and this same rationale has been extended to select patients with locally advanced disease who demonstrate an exceptional response to induction therapy.

Randomized phase II study of PEGPH20 plus nab-paclitaxel/gemcitabine (PAG) vs AG in patients (Pts) with untreated, metastatic pancreatic ductal adenocarcinoma (mPDA)

4008

Background: Hyaluronan (HA) accumulation in the tumor microenvironment produces elevated tumor pressure, vascular compression, and reduced drug delivery. PEGPH20 degrades HA, increasing the access and therapeutic index of anticancer agents. Methods: In Stage 1 of this phase II study, pts with untreated mPDA were randomized 1:1 to PAG (P; 3 µg/kg IV 2x/wk x 3 wks in C1, then 1x/wk x 3 wks in C2+, plus AG) vs AG every 28 days. An imbalance in thromboembolic (TE) events in the PAG arm led to a clinical hold (~40% of pts discontinued PEGPH20), exclusion of pts at high risk for TE events and enoxaparin prophylaxis in both study arms. In Stage 2, randomization was 2:1 to PAG vs AG. Tumor HA was tested using a novel assay (VENTANA HA RxDx). Primary endpoints were PFS (evaluable pts) and TE event rate (Stage 2). Secondary endpoints were PFS by HA level and ORR. Results: 279 pts were randomized; 231 are evaluable for efficacy. Of 246 pts with HA data, 84 (34%) were HA-High. As of December 16, 2016, the primary PFS endpoint was statistically significant for PAG vs AG (HR 0.73, 95% CI 0.53-1.00; p = 0.048) (Table). PFS in HA-High pts was also statistically significant in the PAG vs AG arm (HR 0.51; 95% CI 0.26-1.00; p = 0.048). ORR in HA-High pts was 46% (PAG) vs 34% (AG). Overall survival in HA-High pts (exploratory) was 11.5 months (mo) (PAG) and 8.5 mo (AG) (HR 0.96, 95% CI 0.57-1.61). TE events were similar (PAG 14% vs AG 10%) following enoxaparin initiation. All grade treatment-related AE included peripheral edema (PAG 63% vs AG 26%), muscle spasms (56% vs 3%), neutropenia (34% vs 19%), and myalgia (26% vs 7%). Conclusions: Randomized Phase II study met both primary endpoints (PFS and TE event rate), with the largest improvement in the secondary endpoint of PFS in HA-High pts. These data support HA as a potential predictive biomarker for patient selection of PEGPH20, currently investigated in the ongoing global Phase III HALO 301 study with PFS and OS as co-primary endpoints. Clinical trial information: NCT01839487. [Table: see text]

Prognostic value of positron emission tomography and preoperative CA19-9 in patients treated on a prospective phase II trial of neoadjuvant therapy and surgery

e15766

Background: The role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging of pancreatic cancer (PC) has not been well defined. We evaluated the prognostic value of FDG-PET imaging in patients with localized PC enrolled in a prospective trial of personalized molecular-directed neoadjuvant therapy. Methods: Pretreatment FDG-PET was classified as high or low based on a standardized uptake value (SUV) cutpoint of 7.2 (population median). Carbohydrate antigen 19-9 (CA19-9) was measured after the completion of neoadjuvant therapy (preoperative) and classified as normal (≤35 U/mL) or elevated. Results: Pretreatment FDG-PET imaging was performed on 100 consecutive patients; SUV was high in 50 and low in 50. Preoperative CA19-9 values were available in 99 of 100 patients; 54 (55%) were elevated and 45 (45%) were normal. Of the 100 patients, 81 completed neoadjuvant therapy and surgery, and 19 were not resected. Among the 81 resected patients, SUV was high in 37 (46%) and low in 44 (54%); preoperative CA19-9 was elevated in 40 (49%) and normal in 41 (51%). The median overall survival (OS) for all patients was 39 months; 45 months for who completed all intended neoadjuvant therapy and surgery and 9 months for patients who were not resected. The median OS for patients with normal CA19-9/low SUV, normal CA19-9/high SUV, elevated CA19-9/low SUV, and elevated CA19-9/high SUV were not reached, 35, 24, and 18 months, respectively (p = 0.0001). Conclusions: Pretreatment FDG-PET avidity and preoperative CA19-9 are important prognostic markers and may be used to estimate the anticipated benefit of surgery; information of immediate clinical significance for both treatment sequencing and the application of surgery to patients who are frequently of advanced age or high-risk.

Poor Glycemic Control Is Associated with Failure to Complete Neoadjuvant Therapy and Surgery in Patients with Localized Pancreatic Cancer

BACKGROUND

The impact of glycemic control in patients with pancreatic cancer treated with neoadjuvant therapy is unclear.

METHODS

Glycated hemoglobin (HbA1c) values were measured in patients with localized pancreatic cancer prior to any therapy (pretreatment) and after neoadjuvant therapy prior to surgery (preoperative). HbA1c levels greater than 6.5% were classified as abnormal. Patients were categorized based on the change in HbA1c levels from pretreatment to preoperative: GrpA, always normal; Gr B, worsened; GrpC, improved; and GrpD, always abnormal.

RESULTS

Pretreatment HbA1c levels were evaluable in 123 patients; there were 67 (55%) patients in GrpA, 8 (6%) in GrpB, 22 (18%) in GrpC, and 26 (21%) in GrpD. Of the 123 patients, 92 (75%) completed all intended therapy to include surgery; 57 (85%) patients in GrpA, 4 (50%) patients in GrpB, 16 (72%) patients in GrpC, and 15 (58%) patients in GrpD (p = 0.01). Elevated preoperative carbohydrate antigen 19-9 (CA19-9) (OR 0.22;[0.07-0.66]), borderline resectable (BLR) disease stage (OR 0.20;[0.01-0.45]) and abnormal preoperative HbA1c (OR 0.30;[0.11-0.90]) were negatively associated with completion of all intended therapy. Abnormal preoperative HbA1c was associated with a 2.74-fold increased odds of metastatic progression during neoadjuvant therapy (p = 0.08).

CONCLUSIONS

Elevated preoperative HbA1c is associated with failure to complete neoadjuvant therapy and surgery and a trend for increased risk of metastatic progression.

Results of a randomized phase II trial of an anti-notch 2/3, tarextumab (OMP-59R5, TRXT, anti-Notch2/3), in combination with nab-paclitaxel and gemcitabine (Nab-P+Gem) in patients (pts) with untreated metastatic pancreatic cancer (mPC)

279

Background: Tarextumab (TRXT), fully human IgG2 antibody inhibits signaling of Notch2/ 3 receptors. Tumor regression seen in Notch3 (N3) expressing pt-derived pancreatic cancer xenografts when TRXT combined with Nab-P+Gem. Phase 2, randomized, placebo-controlled trial conducted to evaluate efficacy, safety of combination in mPC. Methods: Pts randomized 1:1 to TRXT or placebo (PL). TRXT given IV at 15 mg/kg q 2wks (D 1, 15), nab-P 125 mg/m2, GEM 1000mg/m2 on D1, 8, 15 q 28 days. Tissue for N3 gene expression determination was required. Primary endpoints: overall survival (OS) in all and in 3 subgroups determined by Notch 3 gene expression. Secondary: safety, progression-free survival (PFS) and overall response rate (ORR). Results: N = 177 pts randomized. Performance status (0 or 1), CA19-9 stratum (0 – ULN, > ULN – 59ULN, ≥ 59ULN) balanced. Clinical trial information: NCT01647828. .  Conclusions: Addition of TRXT to Nab-P+Gem did not improve OS in 1st line mPC. A potential detrimental effect on PFS and ORR was seen in subjects with N3 < 25%ile.[Table: see text]

Impact of age on genomic alterations associated with pancreatic ductal adenocarcinoma (PDAC)

282

Background: Large scale, retrospective, sequencing projects have identified well-defined subtypes of PDAC, but therapeutic paradigms remain unchanged. We hypothesized that genomic alterations associated with PDAC in young adults (YA, age < 50) are distinctly different from that of older adults (OA, age > 50) to identify an enrichment of targetable alterations. Methods: DNA was extracted from formalin fixed paraffin embedded (FFPE) PDAC clinical specimens and comprehensive genomic profiling (CGP) was performed on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. Results: CGP was performed on 1533 FFPE PDAC specimens, 566 (36.9%) were from the primary tumor, 967 (63.1%) from metastatic sites. Median age at diagnosis was 63 years (yrs), 180 (11.7%) were YA. KRAS mutations were identified in 78.7 of YA and 87.7% of OA. The differentially altered genes between the two groups were KRAS (p = 0.004), TP53 (p = 0.04), BRCA2 (p = 0.02), AKT2 (p = 0.03), MAP2K4 (P = 0.003) and DNMT3A (p = 0.0002). The median tumor mutational burden (TMB) for the entire study set was 2.7 (YA – 2.5, OA –2.7). BRAF kinase domain deletion was observed in 1 patient (OA). ALK fusions were present in 2 patients (1 YA & 1 OA) and these patients had durable responses to specific ALK inhibitors. Conclusions: The majority of the genomic alterations identified were not significantly different on the basis of age. However, identification of subpopulations, such as ALK kinase fusions and BRAF kinase domain deletions that can translate into sustained clinical benefit from matched targeted therapy is promising. This underscores the importance of CGP in PDAC to investigate other targetable genomic alterations.

Should functional renal scans be obtained prior to upper abdominal radiation for pancreatic cancer?

442

Background: Upper abdominal irradiation for pancreas cancer is given in close proximity to the radiation sensitive kidneys. While contemporary 3D and intensity modulated radiation therapy (IMRT) can decrease the total dose of radiation delivered to the kidneys; these plans may potentially exceed the established kidney dose constraints, especially if one kidney is providing most of the renal function. Less than 10% of the general population is estimated to have asymmetrical kidney function. Functional kidney scans using MAG3 clearance can give information about the contribution of each kidney to total renal function. We sought to determine if functional renal scans should be used to identify patients with occult renal dysfunction. Methods: Patients with resectable and borderline resectable pancreatic cancer who received abdominal irradiation therapy and had pre-radiation functional renal scans between 2009-2015 were studied. Asymmetrical kidney function was defined as a difference between the two kidneys that was ≥ 40%/60% on a functional renal scan. Serum studies (BUN, Cr, GFR) were routinely obtained pre-simulation. Restaging abdominal CT scans prior to radiation were screened for disparity in kidney size. Medical history that suggested decreased renal function was also collected. Results: Of the 205 patients examined, 24 (11.7%) had asymmetrical kidney function identified on pre-radiation functional renal scans. Of the patients with asymmetrical kidney function, 4 (2%) had a 75%/25% split or greater and 20 (9.7%) had kidney function between 60%/40% and 75%/25%. Elevated Cr or BUN, a GFR < 60, or a past medical history suggesting abnormal renal function were not significantly associated with asymmetrical kidney function. Only six (25%) of patients with asymmetrical kidney function scans had a notable difference in kidney size. Conclusions: In our series, approximately 12% of patients with pancreatic cancer have asymmetrical kidney function not identified by size, serum BUN, Cr, GFR, or a significant past medical history of renal compromise. These results provide important insight for cases when radiation plans may approach or exceed accepted dose constraints for the kidneys.

Venous thromboembolism prophylaxis during neoadjuvant therapy for resectable and borderline resectable pancreatic cancer-Is it indicated?

PURPOSE

To describe venous thromboembolism (VTE) rates in patients with pancreatic cancer (PC) during neoadjuvant therapy.

METHODS

Factors associated with VTE were evaluated using multivariable logistic regression modeling in patients with resectable and BLR PC treated with neoadjuvant therapy between 2009 and 2014.

RESULTS

Prevalent VTEs were detected in 13 (5%) of the 260 patients. Incident VTEs were detected in 26 patients (10%); 9 (8%) of the 109 resectable and 17 (11%) of the 151 BLR patients (P = 0.53). Of the 26 incident events, 9 (35%) were PEs, 9 (35%) were extremity DVTs, and 8 (31%) involved the SMV/PV. VTEs were catheter-related in 7 (27%) of the 26 patients. Rh(D) antigen positivity was associated with a decreased risk of incident VTE (OR:0.32, 95%CI:0.11-0.85, P = 0.02). Completion of neoadjuvant therapy to include surgery occurred in 176 (75%) of the 234 patients without incident VTE as compared to 14 (54%) of the 26 patients with incident VTE (P = 0.02). The median survival for all 260 patients was 24.3 months: 17.0 months versus 24.6 months for patients who did and did not develop incident VTE during neoadjuvant therapy (P = 0.11).

CONCLUSIONS

Patients with localized PC who receive neoadjuvant therapy are at significant risk of VTE and thromboprophylaxis may be warranted. J. Surg. Oncol. 2016;114:581-586. © 2016 Wiley Periodicals, Inc.

Evolution of the Management of Resectable Pancreatic Cancer

In pancreatic cancer, as with many other solid tumors, a commonly held surgical adage—a chance to cut is a chance to cure—has been promulgated throughout the years. Following such reasoning, surgical extirpation of a localized tumor would prevent tumor dissemination and metastatic tumor progression. However, decades of surgical experience have demonstrated that surgical resection alone provides a limited median survival benefit. Despite the optimization of surgical technique and perioperative management over the past three decades, little progress has been made to improve the limited survival of patients with localized pancreatic cancer who receive surgery. In this article, we discuss the rationale for a novel management strategy for patients with resectable pancreatic cancer, which may improve patient selection and the delivery of multimodality therapy.

Survival of patients with resectable pancreatic cancer who received neoadjuvant therapy

BACKGROUND

Enthusiasm for neoadjuvant therapy is growing from the emerging consensus that pancreatic cancer is a systemic disease at the time of diagnosis. Those who remain in favor of upfront surgery often cite the lack of reported data to support alternative treatment sequencing. We therefore report the results of all patients treated outside of a clinical trial under the direction of a multidisciplinary pancreatic cancer working group.

METHODS

We reviewed all patients with resectable pancreatic cancer treated with neoadjuvant therapy (NeoTx) from 2009 to 2013; we excluded those patients treated on prospective clinical trials as they will be the subject of subsequent reports. Data regarding demographics, NeoTx, operative outcomes, pathology, and survival data were abstracted from a prospective database.

RESULTS

NeoTx was initiated in 69 patients; median age was 65 years (interquartile range [IQR]: 11) and median carbohydrate antigen 19-9 at diagnosis was 96.5 (IQR 210). NeoTx consisted of chemotherapy alone (n = 10, 14%), chemotherapy and radiation (chemoradiation, n = 53, 77%), or both (n = 6, 9%). Median carbohydrate antigen 19-9 after NeoTx was 39 (IQR 104) corresponding to a median decrease of 60%. Operative resection was completed in 60 (87%) of the 69 patients. At restaging after NeoTx, 5 (7%) of 69 patients were not considered candidates for surgery because of the development of metastatic disease (n = 4) or an inadequate performance status (n = 1). At the time of surgery, 4 (6%) of 64 patients had metastatic disease found at laparoscopy. Of the 60 patients who underwent surgical resection, a complete pathologic response was observed in 2 (3%) patients; 20 (33%) had positive lymph nodes, and the median number of positive lymph nodes was 2 (IQR 3). R0 resections were achieved in 58 (97%) of the 60 patients. Additional postoperative adjuvant therapy was administered to 37 (62%) of the 60 patients. Median survival of all 69 patients was 31.5 months; 44.9 months for the 60 patients who completed all NeoTx and resection compared with 8.1 months for the 9 patients who were not resected (log rank P < .001).

CONCLUSION

NeoTx for resectable pancreatic cancer was associated with a median overall survival of 32 months; something not reported for patients treated with surgery first if based on intent-to-treat analysis. Treatment sequencing may provide an oncologic benefit beyond that of the selection bias afforded surgery after a period of induction therapy.

Rapid immunohistochemical analysis of pancreatic cytology from endoscopic ultrasound-guided fine-needle aspirates: A prospective clinical trial

400

Background: Acquisition of pancreatic cancer (PC) tissue specimens from endoscopic ultrasound-guided fine needle aspirates (EUS-FNA) is crucial to investigational pancreatic cancer trials seeking to utilize molecular profile directed therapy. Methods: In an ongoing prospective clinical trial we have utilized molecular profiling of EUS-FNA specimens from patients with resectable and borderline resectable pancreatic cancers. Cytologic specimens were evaluated for six biomarkers to guide the choice of neoadjuvant therapy: secreted protein acid rich in cysteine (SPARC), thymidylate synthase (TYMS), ribonucleotide reductase M1 (RRM1), human equilibrative nucleoside transporter 1 (ENT1), excision repair cross-complementing 1 (ERCC), and topoisomerase 1 (TOPO). Final immunohistochemical (IHC) interpretation was scored by a single pathologist using both staining intensity and percent immunochemically reactive cells. Results: The trial has enrolled 99 patients to date; 47 (47%) resectable patients and 52 (52%) borderline resectable patients. No patient experienced a EUS-FNA related complication. IHC profiling was reported in a median of 5 business days (IQR:3). Of the 99 patient samples, 73 (74%) had adequate cellularity for IHC profiling and this was not affected by stage of disease (n = 35, resectable; n = 38 borderline resectable; p = 0.82). Analysis of SPARC expression was limited to specimens with adequate stromal cells for analysis (n = 50, 51%). Among the 73 patients with adequate tissue for profiling, expression profiling was interpreted to be favorable for the following therapeutic agents: nab-paclitaxel, (SPARC, n = 35, 48%), 5-fluorouracil (TYMS, n = 68, 93%), gemcitabine (RRM1, n = 34, 47%; ENT1, n = 38, 52%), platinum agents (ERCC, n = 30, 41%), and irinotecan (TOPO, n = 62, 85%). Conclusions: The use of EUS-FNA specimens for molecular diagnostics is feasible and IHC analysis was possible in 74% of patient specimens, with preservation of stromal components in over 50%. Further refinement of molecular techniques may expand the breadth of analysis which may be performed, to include quantitative polymerase chain reaction and genetic sequencing Clinical trial information: NCIT01726582.

Can the sequence of chemotherapy regimens influence outcome in patients with metastatic pancreatic adenocarcinoma (MPAC)?

428

Background: FOLFIRINOX(FFX)/FOLFOX(FX) and Nab-paclitaxel plus Gemcitabine (NabG) represent standard first line (FL) treatment options for MPAC, but there is no prospective data to ascertain the ideal sequence of these regimens when used off protocol for patients with MPAC. We reviewed our single institution experience to evaluate whether the sequence of these regimens influenced clinical outcome. Methods: All MPAC patients treated with FFX/FX or NabG, in either sequence, from 1/1/11 to 12/31/14 at the Froedtert and Medical College of Wisconsin (MCW) Clinical Cancer Center were identified and their charts reviewed. This study was approved by the Froedtert & MCW Institutional Review Board. Results: Among 64 patients reviewed, the median age at diagnosis was 62. 64.1% were male and 95.3% were Caucasian. Median Ca19-9 and CEA at diagnosis were 855 and 10.4 respectively. 37/64 (57.8%) patients received SL therapy. Details of treatment and disease control rate (DCR) are summarized in the Table. Of patients who were refractory to FL FFX/FX, 4/7 (57.1%) demonstrated disease control (DCR) with SL NabG; numbers were too small for reverse analysis. Median overall survival (OS) of patients who received 2 lines of therapy was 12.1 months, while median OS of patients who received one line was 4.1 months. Median OS associated with sequential therapy is summarized in the Table. Conclusions: Both FFX/FX and NabG are active in the SL setting. Outcomes appear to be fairly similar regardless of sequence. The numerically superior median OS associated with FL NabG followed by SL FFX should be interpreted with caution in the context of small number of patients in this subset. A substantial minority of patients do not receive second line chemotherapy due to deteriorating clinical status and/or patient preference suggesting unfavorable tumor biology. [Table: see text]

Outcomes in metastatic pancreatic adenocarcinoma (MPAC) patients treated with FOLFIRINOX (FFX)/FOLFOX(FX) and gemcitabine + nab-paclitaxel (NabG)

397

Background: Standard front line (FL) chemotherapy regimens for MPAC include FOLFIRINOX (FFX)/FOLFOX(FX) and Nab-paclitaxel plus Gemcitabine (NabG). Outcome data in patients treated with both FFX/FX and NabG has not been well characterized. We retrospectively reviewed our single institution experience in MPAC patients treated with FFX/FX and NabG in either sequence. Methods: All MPAC patients treated with FFX/FX or NabG, in either sequence, from 1/1/11 to 12/31/14 at the Froedtert and Medical College of Wisconsin (MCW) Clinical Cancer Center were identified and their charts reviewed. This study was approved by the Froedtert & MCW Institutional Review Board. Results: Among the 64 patients reviewed, median age at diagnosis was 62 years, 64.1% were male and 95.3% were Caucasian. Median Ca19-9 and CEA at diagnosis were 855 and 10.4 respectively. Liver, lung and peritoneal metastases were appreciated in 87.5%, 20.3% and 35.9% of patients. 37/64 (57.8%) patients received second line (SL) therapy. Response Rate (RR) with FFX/FX and NabG in both FL and SL therapy are summarized in the Table. The median Progression Free Survival (PFS) with FL therapy was 3.7 months and 3.5 months with SL therapy. Median overall survival (OS) of the entire cohort was 8.7 months. In patients who received 2 lines of therapy the median OS was 12.1 months. Median OS in patients who received only one line of therapy was 4.1 months. Conclusions: In patients with MPAC, sequential therapy with FFX/FX and NabG is both feasible and effective in either sequence. RR and DCR with these regimens, while modest, are acceptable in the SL setting. Patients who received two lines of therapy have a substantially better OS than patients who receive one line of therapy, suggesting a more favorable tumor biology in the former population. [Table: see text]

Can response to treatment predict outcome in patients with metastatic pancreatic adenocarcinoma (MPAC)?

443

Background: Front-line (FL) chemotherapy regimens for MPAC include FOLFIRINOX (FFX)/FOLFOX (FX) and Nab-paclitaxel plus Gemcitabine (NabG). We examined our hypothesis that objective response (OR) to these regimens can influence clinical outcome when employed sequentially. Methods: All MPAC patients treated with FFX/FX or NabG from 1/1/2011 to 12/31/2014 at the Froedtert and Medical College of Wisconsin (MCW) Clinical Cancer Center were reviewed. This study was approved by the MCW Institutional Review Board. Results: 64 patients were evaluated and the baseline characteristics are summarized in the table below. OR to FL chemotherapy included partial response(PR) - 23/64 (35.9%), stable disease (SD) - 14/64 (21.9%) and disease control rate (DCR) of 57.8%; OR to second line (SL) therapy included PR - 7/37 (18.9%), SD - 14/37 (37.8%) and DCR of 56.7%. Only 57.8% patients received SL chemotherapy. Among patients who demonstrated PR to FL chemotherapy, 64% were refractory to SL chemotherapy, while 33% of patients who were refractory to FL chemotherapy demonstrated a PR to SL chemotherapy. 3/64 patients who demonstrated PR to both FL and SL chemotherapy had excellent outcomes with overall survival (OS) of 20.9 months, 37 months and not met (PFS of 11 months to FL chemo and ongoing response of > 4 months to SL chemo). Median OS of patients who demonstrated a PR/SD to FL and SL chemotherapy (15/64; 23.4 %) was 20.9 months. The patients who demonstrated progressive disease(PD) to both FL and SL chemotherapy (5/64; 7.8%) had a median OS of 3.8 months. Conclusions: Patients with MPAC who are refractory to FL chemotherapy may demonstrate a response to SL chemotherapy. Patients who are able to undergo sequential therapy with FFX/FX and NabG (in either sequence) and demonstrate either a PR or SD with both treatment regimens have an excellent clinical outcome. The minority of patients who demonstrate PR to both sequential regimens have a distinctly different outcome compared to patients who demonstrate PD to both regimens; tumors from these two subsets of patients need to be better characterized to improve our understanding of pancreatic cancer biology. [Table: see text]

Interim results of a randomized phase II study of PEGPH20 added to nab-paclitaxel/gemcitabine in patients with stage IV previously untreated pancreatic cancer

439

Background: Poor outcome in pancreatic cancer (PDA) is associated partly with stromal hyaluronan (HA) accumulation, which compromises chemotherapy perfusion. PEGPH20, PEGylated recombinant human hyaluronidase, potentiates chemotherapy by depleting HA in tumors. Methods: In an ongoing, phase II, open-label, randomized study of PEGPH20+nab-paclitaxel (Nab)+Gemcitabine (Gem) (PAG) vs Nab+Gem (AG) in previously untreated stage IV PDA, pts receive PEGPH20 3 µg/kg twice weekly (C1), then weekly (C2+) with standard AG dosing. HA status was tested retrospectively. After a temporary clinical hold (Apr-Jul 2014) for an imbalance in thromboembolic (TE) events (29% PAG vs 15% AG), the protocol was amended to exclude high-TE-risk pts and add enoxaparin (LMWH) prophylaxis. Endpoints are PFS and TE events (primary); PFS and ORR by HA level and OS (secondary). Efficacy and safety data through Dec 2014 are for pts enrolled up to clinical hold (Stage 1); TE data are through Sep 2015 (Stage 2). Results: 135 pts were treated (74 PAG, 61 AG). PFS results are shown below (median follow-up 7 mo). In HA-high pts receiving PAG vs AG, ORR was 52% (1 CR) vs 24% (P=.038); ORR was 37% vs 38% in HA-low pts. OS was 12 mo vs 9 mo (HR=0.62) despite 12/23 PAG pts discontinuing PEGPH20 at clinical hold. Common ADRs (PAG vs AG) included peripheral edema (58% vs 31%), muscle spasms (55% vs 1.6%), and neutropenia (32% vs 18%). TE events were: Stage 1 42% vs 25% (no LMWH); Stage 2 (with LMWH; 40 mg/d or 40 mg/d increased to 1 mg/kg/d) 28% vs 29%; (1 mg/kg/d) 5% vs 6%; overall (40 mg/d or 1 mg/kg/d) 13% each arm (to be updated). Conclusions: Pts with HA-high tumors receiving PAG, vs AG, showed significant improvements in PFS and ORR and a trend toward improved OS. PAG was well tolerated, with TE events reduced with LMWH prophylaxis. A global phase III trial of PAG will initiate Q1 2016. Clinical Trial Information: NCT01839487. Clinical trial information: NCT01839487. [Table: see text]

Pre-treatment carbohydrate antigen 19-9 does not predict the response to neoadjuvant therapy in patients with localized pancreatic cancer

BACKGROUND

The prognostic value of CA19-9 in patients with pancreatic cancer (PC) treated with neoadjuvant therapy has not been well described.

METHODS

Pre-treatment CA19-9 levels (with concomitant normal bilirubin level) in patients with localized PC were categorized as normal (≤35), low (36-200), moderate (201-1000), or high (>1000). Post-treatment CA19-9 was measured after neoadjuvant therapy, prior to surgery.

RESULTS

Pre-treatment CA19-9 levels were evaluable in 235 patients, levels were normal in 60 (25%) patients, low in 78 (33%) patients, moderate in 69 (29%) and high in 28 (12%). After neoadjuvant therapy, post-treatment CA19-9 normalized (≤ 35) in 40 (51%) of the patients in the low group, 14 (21%) of the moderate and 5 (19%) of the high group (P < 0.001). Of the 235 patients, 168 (71%) completed all intended therapy including a pancreatectomy; 44 (73%), 62 (79%), 46 (67%) and 16 (57%) of the normal, low, moderate and high groups (P = 0.10). Among these 168 patients, the median overall survival was 38.4, 43.6, 44.7, 27.2 and 26.4 months for normal, low, moderate and high CA19-9 groups (log rank P = 0.72). Among resected patients, an elevated pre-treatment CA19-9 was of little prognostic value; instead, it was the CA19-9 response to neoadjuvant therapy that was prognostic [hazard ratio (HR): 1.80, P = 0.02].

CONCLUSIONS

Among patients who completed neoadjuvant therapy and surgery, pre-treatment CA19-9 obtained at the time of diagnosis was not predictive of overall survival, but normalization of post-treatment CA19-9 in response to neoadjuvant therapy was highly prognostic.

Use of neoadjuvant therapy in patients 75 years of age and older with pancreatic cancer

BACKGROUND

Treatment sequencing in older patients is difficult because of concomitant comorbidities and often decreasing performance status. The present study sought to examine the effect of neoadjuvant therapy and pancreatic surgery in older patients with resectable or borderline-resectable (BLR pancreatic cancer (PC).

METHODS

Patients with resectable or BLR PC treated with neoadjuvant therapy were classified as older (≥ 75 years) or younger (<75 years).

RESULTS

Neoadjuvant therapy was initiated in 246 patients; 210 (85%) younger than 75 years and 36 (15%) older. Older patients had a greater median Charlson comorbidity index (CCI): 6 vs 4 (P < .01). Completion of all intended therapy (neoadjuvant therapy and surgery) occurred in 177 (72%) of the 246 patients; 153 (73%) of the 210 younger and 24 (67%) of the 36 older patients (P = .43). Failure to complete all therapy was associated with BLR clinical stage (odds ratio [OR] 0.26, P = .001), increased posttreatment/preoperative serum levels of CA19-9 (OR 0.27, 95% confidence interval 0.14-0.53), and CCI ≥ 6 (OR 0.44, 95% confidence interval 0.22-0.86). Median overall survival for all study patients was 26.1 and 19.7 months (P = .13) for younger and older patients, respectively. Of the 177 patients who completed all therapy, the difference in survival between younger and older patients was not statistically significant (36.5 months vs 27.2 months, P = .47).

CONCLUSION

Failure to complete neoadjuvant therapy and eventual pancreatic resection is associated with BLR stage, increased posttreatment/preoperative CA19-9, and CCI ≥ 6, but not older age. Older patients who completed neoadjuvant therapy and underwent resection experienced a survival benefit compared with those who did not complete all intended therapy. Balancing the toxicity of sequential therapies with their cumulative effect on tolerance and risk for pancreatic surgery will be the key to developing optimal treatment sequencing in older patients with PC.

Neoadjuvant therapy for localized pancreatic cancer: guiding principles

The management of localized pancreatic cancer (PC) remains controversial. Historically, patients with localized disease have been treated with surgery followed by adjuvant therapy (surgery-first approach) under the assumption that surgical resection is necessary, even if not sufficient for cure. However, a surgery-first approach is associated with a median overall survival of only 22-24 months, suggesting that a large proportion of patients with localized PC have clinically occult metastatic disease. As a result, adjuvant therapy has been recommended for all patients with localized PC, but in actuality, it is often not received due to the high rates of perioperative complications associated with pancreatic resections. Recognizing that surgery may be necessary but usually not sufficient for cure, there has been growing interest in neoadjuvant treatment sequencing, which benefits patients with both localized and metastatic PC by ensuring the delivery of oncologic therapies which are commensurate with the stage of disease. For patients who have clinically occult metastatic disease, neoadjuvant therapy allows for the early delivery of systemic therapy and avoids the morbidity and mortality of a surgical resection which would provide no oncologic benefit. For patients with truly localized disease, neoadjuvant therapy ensures the delivery of all components of the multimodality treatment. This review details the rationale for a neoadjuvant approach to localized PC and provides specific recommendations for both pretreatment staging and treatment sequencing for patients with resectable and borderline resectable (BLR) disease.

Diagnostic laparoscopy should be performed before definitive resection for pancreatic cancer: a financial argument

OBJECTIVES

Laparoscopy is recommended to detect radiographically occult metastases in patients with pancreatic cancer before curative resection. This study was conducted to test the hypothesis that diagnostic laparoscopy (DL) is cost-effective in patients undergoing curative resection with or without neoadjuvant therapy (NAT).

METHODS

Decision tree modelling compared routine DL with exploratory laparotomy (ExLap) at the time of curative resection in resectable cancer treated with surgery first, (SF) and borderline resectable cancer treated with NAT. Costs (US$) from the payer's perspective, quality-adjusted life months (QALMs) and incremental cost-effectiveness ratios (ICERs) were calculated. Base case estimates and multi-way sensitivity analyses were performed. Willingness to pay (WtP) was US$4166/QALM (or US$50,000/quality-adjusted life year).

RESULTS

Base case costs were US$34,921 for ExLap and US$33,442 for DL in SF patients, and US$39,633 for ExLap and US$39,713 for DL in NAT patients. Routine DL is the dominant (preferred) strategy in both treatment types: it allows for cost reductions of US$10,695/QALM in SF and US$4158/QALM in NAT patients.

CONCLUSIONS

The present analysis supports the cost-effectiveness of routine DL before curative resection in pancreatic cancer patients treated with either SF or NAT.

Utility of invasive staging procedures in patients (pts) with localized esophageal cancer (EC)

54

Background: Definitive treatment for localized EC involves surgery alone or tri-modality therapy (TMT-chemotherapy, radiation, and surgery). TMT is administered to pts with clinical T2 or higher and lymph node (LN) positive ECs. Standard staging includes Computerized Tomography (CT)/Positron Emission Tomography (PET) imaging and Endoscopic Ultrasound (EUS). We investigated whether performing an EUS altered treatment decision in localized EC pts where a combination of imaging and clinical symptoms suggested the need for TMT. Methods: We performed a retrospective review to identify pts with localized EC who had their staging work up and treatment at the Medical College of Wisconsin between 2003 and 2012. Relevant clinical information was collected through review of the electronic medical record. Results: We identified 65 pts; median age at diagnosis was 62 years, 49 (75%) were male, and 56 (86%) were Caucasian. Histology was adenocarcinoma in 48 (74%) pts with 21 (44%) having background Barrett’s esophagus. Common presenting symptoms included dysphagia (83%), weight loss (73%), and odynophagia (25%). Staging evaluation included CT, PET, and EUS in 100%, 98%, and 89% of pts respectively. EUS staging results are in the table below. Dysphagia was reported by 67% of T1, 80% of T2, 84% of T3, 50% of T4, and 100% of Tx pts; 70% of pts with dysphagia were node positive by EUS. PET positive primary tumors/LNs were found in 89%/29% of all pts and 89%/33% of pts with dysphagia. Of the pts with PET positive LNs, 68% had node positive disease on EUS. Eighteen (28%) pts had both dysphagia and PET positive LNs, none with T1-2N0 staging by EUS; 36 pts had dysphagia and PET negative LNs, 7 (19%) with T1-2N0 staging by EUS. Among those 7 pts, 4 underwent surgery (1 pt-pT3N1aMx; 3pts-pT1bN0Mx). Conclusions: Localized EC pts with both dysphagia and PET positive LNs are candidates for TMT even in the absence of EUS staging. The role of EUS in this population may be limited to investigating adjacent organ invasion or confirmation of LN involvement. With improving PET capabilities, the role of EUS in this pt population needs to be studied prospectively. [Table: see text]

Abstract 813: A combination of cisplatin, irinotecan, and paclitaxel (CIP) as frontline treatment of patients with metastatic esophageal cancer (mEC)

Introduction: Median survival associated with mEC is 9-12 months. While systemic therapy is the mainstay of treatment for mEC, there is no consensus regarding the best frontline chemotherapy combination. We evaluated the efficacy of CIP (Cisplatin 30 mg/m2, Irinotecan 50 mg/m2 and Paclitaxel 50 mg/m2 on days 1 and 8 of a 21 day cycle) in patients with mEC.

Methods: We performed a retrospective review to identify mEC patients at the Medical College of Wisconsin (MCW) who were treated with frontline CIP between January 1, 2005 and December 31, 2010. Relevant clinical information was collected through a review of the electronic medical record. This study was approved by the Institutional Review Board at MCW.

Results: We identified 13 patients who were treated with CIP as frontline therapy for mEC. The median age at diagnosis was 59 years (range 48-71 years), 12 (92%) patients were male, and 9 patients (69%) had adenocarcinoma with the remaining being squamous cell carcinoma. Eleven patients (85%) presented with metastatic disease, while 2 patients (15%) were diagnosed with metastatic disease after having undergone initial surgical resection with disease free intervals of 39 and 14 months respectively. The most common sites of metastases were lymph nodes (11 patients), liver (6 patients), lung (4 patients), bone (3 patients), and peritoneum (2 patients); 77% of patients had at least 2 sites of metastases. The median number of chemotherapy cycles administered was 7 (range 1-14). Four patients (31%) developed grade 3/4 toxicities including neutropenia in 3 patients, nausea in 1 patient, and anemia in 1 patient. One patient (8%) had a complete response (CR), 7 patients (54%) had a partial response (PR), 2 patients (15%) had stable disease (SD), and 3 patients (23%) developed progressive disease (PD). The median progression free survival (PFS) was 5 months (range 0-29 months) and the median overall survival (OS) was 10 months (range 3-36 months).

Conclusion: CIP is an active and well tolerated regimen in patients with mEC that merits prospective evaluation.

Citation Format: Thomas A. Giever, Paul S. Ritch, James P. Thomas, Lauren A. Wiebe, George B. Haasler, Mario G. Gasparri, David Johnstone, Candice A. Johnstone, Elizabeth M. Gore, Ben George. A combination of cisplatin, irinotecan, and paclitaxel (CIP) as frontline treatment of patients with metastatic esophageal cancer (mEC). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 813. doi:10.1158/1538-7445.AM2014-813

Neoadjuvant therapy for pancreatic cancer in patients older than age 75

287

Background: Multiple treatments in series may be difficult for older patients (pt) to tolerate. We sought to examine the outcomes associated with neoadjuvant therapy in older pt with resectable (R) or borderline resectable (BLR) pancreatic cancer (PC). Methods: Pt ≥75 years (O) with those <75 (Y) with R or BLR PC receiving neoadjuvant therapy from 2008-2012 were identified. Clinicopathologic and treatment data were abstracted. Completion of all therapy was defined as the receipt of neoadjuvant therapy followed by surgical resection. Results: We identified 77 (42.5%) R and 104 (57.5%) BLR pt; 29 (16%) were ≥ 75 years. Higher Charlson Comorbidity Index (CCI) (median CCI 4 vs. 2, p<0.01) and more hospitalizations during neoadjuvant therapy (50% vs. 28%, p=0.04) were associated with O vs. Y pt. Older pt were less likely to complete all therapy as compared to Y pt (72.4 vs. 89.5%, p<0.01). Poor performance status was the most common reason for failure to complete all therapy in O vs. Y pt (17.2% vs. 0.7%; p<0.01). Higher CCI (OR 0.25; 95% CI: 0.08-0.74, p=0.01) and higher clinical stage (OR 0.17; 95%CI: 0.06-0.48, p<0.01) were associated with failure to complete all therapy. Of the 138 pt that completed all therapy, no significant differences in complication rates (15 vs. 15.3%, p=0.33), median length of hospital stay (10 vs. 9 days, p=0.29), 30 day readmission rates (10 vs. 11.9%, p=0.81), or median overall survival (24.3 mo vs. 36.7 mo, p=0.20) were observed between O vs. Y pt. Conclusions: After neoadjuvant therapy, 25% of pt ≥ 75 years of age will not undergo surgical resection. The most common reason for not completing all therapy is a decline in performance status. Whether neoadjuvant therapy improves the selection of older pts who should not undergo an operation or prevents successful resection of pt who may have tolerated an operation is unclear. With evolving paradigms of treatment sequencing, the management of PC pt with advanced age will require further assessment.

Phase II clinical trial of biomarker-directed therapy for localized pancreatic cancer

TPS4147

Background: Several candidate biomarkers exist for the common chemotherapeutic agents used to treat pancreatic cancer (PC) (Table). The predictive value of these markers in the treatment of PC has not been established. This is the first prospective clinical trial utilizing biomarker-directed therapy for localized pancreatic cancer. Methods: Patients with localized pancreatic cancer undergo endoscopic ultrasound-guided fine needle aspiration (FNA) for confirmation of diagnosis and immunohistochemical profiling . Six biomarkers (STREET profile) were selected based on their relevance to accepted pancreatic chemotherapy regimens (table). The treatment algorithm selected for each individual patient is based on the clinical stage of resectability (resectable/borderline resectable) and the STREET profile results. Neoadjuvant therapy is followed by restaging (CT and serum Ca19-9) and in the absence of disease progression, patients undergo surgery. Post-surgical (adjuvant) therapy is determined by the STREET profile of the resected specimen. The primary endpoint is an increase in the rate of surgical resection 20% compared with historical controls treated with best available neoadjuvant therapy which was not biomarker-directed. Secondary endpoints include assessment of overall and progression-free survival, comparative STREET profiling of pre- and post-treatment specimens, and changes in radiographic response. Eligbility Criteria: Patients with resectable or borderline resectable pancreatic cancer undergo endoscopic ultrasound-guided fine needle aspiration (FNA) for confirmation of diagnosis and immunohistochemical profiling. Enrollment: 26 of planned 100 patients have been enrolled. Clinical trial information: NCT01726582. [Table: see text]

Association of decline in serum Ca19-9 after neoadjuvant therapy with improved survival among borderline resectable pancreatic cancer patients

e15082

Background: Serum Ca19-9 (19-9) decline in response to therapy has been associated with an increased overall survival in metastatic pancreatic cancer patients (pts). However, the prognostic value of a 19-9 decline after neoadjuvant therapy in pts with localized disease is less well defined. Methods: We evaluated 73 pts with NCCN defined BRPC who received neoadjuvant therapy with induction chemotherapy (CRX) followed by chemoradiation (CRT). Staging with CT and 19-9 was obtained at three defined time points: baseline (bilirubin normal), after CRX, and following CRT (pre-surgical). Change in 19-9 (δ19-9) was defined as: (baseline 19-9- pre-surgical 19-9)/baseline 19-9. δ19-9 was classified as: absent (δ19-9<0) or minimal (0 <δ19-9<0.25), low (0.25<δ19-9<0.50), moderate (0.50<δ19-9<0.75), high (δ19-9> 0.75). Results: Of the 73 pts, 20 pts had normal/undetectable 19-9 and were excluded from the analysis. Of the remaining 53 pts, mean 19-9 levels at baseline, after CRX, and after CRT were 956, 164, and 139 U/mL, respectively. The mean change in 19-9 after CRX was 44%. Changes in 19-9 after CRX correlated with continued decline in 19-9 after CRT (Spearman rho = 0.81, p<0.001). δ19-9 was high in 38 (71%), moderate in 9 (17%), min/low in 1 (2%), and absent in 5 (9%). Of the 53 pts, 49 (92%) were considered for surgery after neoadjuvant therapy and 38 (72%) underwent pancreatectomy. In a multivariate logistic regression, higher δ19-9 was associated with a 5.4 fold increased odds of completing all neoadjuvant therapy including surgery as compared to pts with no change in 19-9 (absent δ19-9; HR 5.4, p=0.12). Patients with absent δ19-9 had a worse overall survival than pts with minimal to high δ19-9 (median survival 11.5 mo vs. 30.1 mo, p = 0.0002). In a multivariate Cox proportional hazard, a decline in pre-surgical 19-9 from baseline was associated with improved survival (HR 0.21, p =0.02). Conclusions: Following neoadjuvant therapy, a decline in 19-9 is associated with surgical resection and improved overall survival. An increase in 19-9 above baseline (the absent δ19-9 group) prior to surgery is a poor prognostic marker and such patients may benefit from additional systemic therapy.

Local control in resectable and borderline resectable pancreatic cancer (PCa) treated with preoperative chemoradiation using IMRT or chemotherapy alone

282

Background: The primary objective is to review local control and failure patterns in PCa patients treated with preoperative chemoradiation (chemoXRT) using IMRT compared to patients treated with chemotherapy alone. Methods: All patients with resectable and borderline resectable PCa treated between 1/1/2009 -11/1/2011 were reviewed. During the study period, 68 patients (40 borderline resectable, 28 resectable) were treated with preoperative chemoXRT (50.4 Gy [1.8 Gy/fx] with concurrent gemcitabine [n=59] or capecitabine [n=7]). 12 patients with resectable tumors received gemcitabine based chemotherapy alone and did not receive radiation therapy due to enrollment on chemotherapy only protocols (n=10) or to patient preference (n=2). Radiation was delivered to a CTV that includes the primary mass, the SMA and SMV, +/- the celiac axis. A 4D-CT and daily image guidance were used in all patients. The local failure free interval was defined as the time from surgical resection to local failure or last documented CT scan of the abdomen with no evidence of local disease progression. Results: Following preoperative chemoXRT, 48/68 patients underwent resection with 47(98%) R0 resections. 11/12 patients in the No XRT group undwerent resection with 10 (91%) R0 resections. In the No XRT group, 8/11 (73%) patients failed locally at the SMA/SMV or resection bed as a component of first failure compared to 1/48 (2%) patients who received preoperative chemoXRT (p<0.001). Local failure was the sole site of first failure in 5/11 patients in the No XRT group and 0/48 patients who received preoperative chemoXRT. The actuarial rate of local failure 1 year from surgery was 5% in the preoperative chemoXRT group vs 27% in the No XRT group (p<0.001). All local failures in the No XRT group would have been encompassed using the CTV target volumes used in patients treated with preoperative chemoXRT. Conclusions: IMRT-based, conformal, preoperative chemoXRT for resectable and borderline resectable PCa may facilitate margin negative resection and increase local control. Omission of radiation therapy may result in high rates of local failures at the SMA/SMV vasculature or in the pancreatic bed.

5-FU/leucovorin, irinotecan, oxaliplatin (FOLFIRINOX) induction followed by chemoXRT in borderline resectable pancreatic cancer

e14613

Background: FOLFIRINOX improves overall survival compared to gemcitabine in patients with metastatic PCa. We retrospectively evaluated the feasibility of using induction FOLFIRINOX followed by chemoXRT to improve resectability in borderline resectable PCa. Methods: All patients with borderline resectable, biopsy-proven PCa treated with the FOLFIRINOX between 1/2009 -11/2011 were reviewed. Borderline resectable PCa was defined by computerized tomography (CT) imaging as tumor-induced SMA abutment of <180 degrees, SMV occlusion, or findings suspicious but not diagnostic for metastatic disease. CT imaging was obtained following induction chemotherapy and after chemoXRT prior to surgery. Results: Twelve patients with borderline resectable disease were treated with FOLFIRINOX induction (median of 4 cycles [range 3-8]). Chemotherapy details are listed in table 1. Tumors in 9 patients had SMA abutment or SMV occlusion and the median pre-treatment CA 19-9 was 297 U/ml (1-3432 U/ml ). Following induction chemotherapy, all patients proceeded to chemoXRT (50.4 Gy [1.8 Gy/fx] with concurrent gemcitabine [n=8] or capecitabine [n=4]). The median CA 19-9 reduction following systemic therapy alone was 58%. One patient did not complete chemoXRT due to infectious and hematologic toxicities. Following all neoadjuvant treatment, 7 (58%) of the 12 patients underwent successful PD. All 7 patients who underwent PD had an RO resection and only one patient had lymph node metastases. The median survival has not been met with median follow up of 13 months. Conclusions: In medically fit patients with borderline resectable PCa, induction FOLFIRINOX followed by chemoXRT is feasible and may facilitate a margin negative resection and histologic response in regional lymph nodes. [Table: see text]

Multicenter, randomized phase II trial of bevacizumab plus folinic acid, fluorouracil, gemcitabine (FFG) versus bevacizumab plus folinic acid, fluorouracil, oxaliplatin (FOLFOX4) as first-line therapy for patients with advanced colorectal cancer

PURPOSE

To assess safety and efficacy of folinic acid, 5-fluorouracil, gemcitabine (FFG) and folinic acid, fluorouracil, oxaliplatin (FOLFOX4) regimens with added bevacizumab as first-line treatment in patients with advanced colorectal cancer (CRC).

PATIENTS AND METHODS

Patients with Stage III unresectable or Stage IV adenocarcinoma of the colon or rectum were randomly assigned to either FFG weekly for 6 weeks of an 8-week cycle or FOLFOX4 every 2 weeks. After FDA approval, bevacizumab 5 mg/kg was added every 2 weeks. Treatment continued until disease progression. Planned enrollment was 190 patients. Primary endpoint was overall response rate (ORR); secondary endpoints included evaluation of adverse events, time to progression (TTP), and overall survival (OS). Disease Control Rate (DCR; % of patients with complete or partial responses or stable disease) was a post hoc analysis.

RESULTS

The trial was stopped prematurely due to low enrollment. Of 84 enrolled patients (42 to each arm), 36 patients (18 in each arm) received bevacizumab. ORR was greater (P = .002) for FOLFOX4 (17/42; 40.5%) than for FFG (4/42; 9.5%); however, TTP, OS, and DCR results were not statistically different comparing FOLFOX4 and FFG. Peripheral neuropathy was more frequent (P = <.001) with FOLFOX4 (18/42; 42.9%) than with FFG (1/42; 2.4%).

CONCLUSIONS

FFG and FOLFOX4 were generally well tolerated. Based on ORR, FOLFOX4 was superior to FFG. However, differences in TTP and OS comparing regimens were inconclusive. General use of gemcitabine as a biomodulator of 5-fluorouracil in CRC cannot be recommended at this time and the regimen remains investigational.

Palliative stenting for late malignant gastric outlet obstruction

Malignant gastric outlet obstruction (MGO) is a late complication of pancreatobiliary and gastric cancers. Although surgical gastrojejunostomy provides good palliation, many of these patients may be nonoperative candidates or underwent previous extensive resection such as a Whipple procedure. Recently, endoscopically placed self-expanding metallic stents (SEMS) have been used to palliate MGO. The aim of this study was to evaluate the efficacy of SEMS for palliation of late MGO. Medical records of patients with endoscopic placement of SEMS for palliation of MGO were reviewed. Results showed that 30 patients with MGO had SEMS placed for late gastroduodenal (n = 20) or jejunal (n = 10) obstruction. Twenty-one patients (70%) had previous surgery. Return to oral feeding was observed in 90% of patients who presented with recurrent obstruction after prior bypass surgery and in 88% of nonoperative patients in whom SEMS were placed as the primary therapy for obstruction. No major complications were observed, and median survival after SEMS was 4.1 months (0.1 to 10.5 months). SEMS also did not interfere with biliary drainage. In conclusion, endoscopically placed SEMS are safe and provide good palliation for late malignant gastroduodenal and jejunal strictures and are an excellent complement to recurrent obstruction after surgical gastrojejunostomy.

Modulation of glioma BK channels via erbB2

Glioma cells show up-regulation and constitutive activation of erbB2, and its expression correlates positively with increased malignancy. A similar correlation has been demonstrated for the expression of gBK, a calcium-sensitive, large-conductance K(+) channel. We show here that glioma BK channels are a downstream target of erbB2/neuregulin signaling. Tyrphostin AG825 was able to disrupt the constituitive erbB2 activation in a dose-dependent manner, causing a 30-mV positive shift in gBK channel activation in cell-attached patches. Conversely, maximal stimulation of erbB2 with a recombinant neuregulin (NRG-1beta) caused a 12-mV shift in the opposite direction. RT-PCR studies reveal no change in the BK splice variants expressed in treated glioma cells. Furthermore, isolation of surface proteins through biotinylation did not show a change in gBK channel expression, and probing with phospho-specific antibodies showed no alteration in channel phosphorylation. However, fura-II Ca(2+) fluorescence imaging revealed a 35% decrease in the free intracellular Ca(2+) concentration after erbB2 inhibition and an increase in NRG-1beta-treated cells, suggesting that the observed changes most likely were due to alterations in [Ca(2+)](i). Consistent with this conclusion, neither tyrphostin AG825 nor NRG-1beta was able to modulate gBK channels under inside-out or whole-cell recording conditions when intracellular Ca(2+) was fixed. Thus, gBK channels are a downstream target for the abundantly expressed neuregulin-1 receptor erbB2 in glioma cells. However, unlike the case in other systems, this modulation appears to occur via changes in [Ca(2+)](i) without changes in channel expression or phosphorylation. The enhanced sensitivity of gBK channels in glioma cells to small, physiological Ca(2+) changes appears to be a prerequisite for this modulation.

Improved survival in resected biliary malignancies

BACKGROUND

For many years the prognosis for patients with biliary malignancies has been poor. However, recent advances in radiology and laparoscopy have improved staging, and active biliary stent management may improve outcome in these patients. In the past the goal with surgery was to excise all gross tumor. Now, the surgical goal is to achieve negative microscopic margins even if a major hepatic resection is required. Similarly, chemotherapy or radiation was frequently given in isolation, but chemoradiation has become the standard. Therefore, the aim of this analysis was to determine whether survival has improved with better staging, active stent management, more aggressive surgery, and chemoradiation.

METHODS

From 1990 through 2001, 140 patients with biliary malignancies were treated at the Medical College of Wisconsin. One hundred eleven malignancies were cholangiocarcinomas (intrahepatic, 22%; perihilar, 65%; and distal, 13%), and 29 were gallbladder (GB) cancers. Eighty-six of the 140 patients (61%) underwent exploration (intrahepatic, 58%; perihilar, 57%; distal, 67%, and GB, 72%). Forty-four of these 86 patients (51%) underwent resection (intrahepatic, 64%; perihilar, 41%; distal, 70%; and GB, 52%). Chemoradiation with confocal radiation, 5-fluorouracil, and gemcitabine was used more frequently in the patients resected since 1998.

RESULTS

Thirty-day operative mortality was 4%. In the resected patients (n = 44) the 5-year actuarial survival was 31% and the median survival was 27.8 months. Patients resected between 1998 and 2001 (n = 25) had a median survival longer than 44 months with a 3-year actuarial survival of 70% as compared to patients resected between 1990 and 1997 (n = 19), who had a median survival of 13 months and a 3-year actuarial survival of 21% (P <.01).

CONCLUSIONS

These data suggest that (1) approximately one third of patients with biliary malignancies have resectable disease and (2) surgery in carefully selected patients with adjuvant chemoradiation has improved survival in resected patients. We suspect that a combination of improved staging, active biliary stenting, safe but extensive surgery to obtain negative margins, and newer techniques for chemoradiation have resulted in improved outcomes for patients with biliary malignancies.