Citations

TPS468 Background: Intrahepatic cholangiocarcinoma (iCCA) is a cancer arising from the intrahepatic bile duct. Standard treatment of unresectable, recurrent, or metastatic iCCA is with cytotoxic chemotherapy. FGFR2 gene fusions have been identified as oncogenic drivers in 10–20% of iCCA tumors, but no targeted agents have been established to date. TAS-120 is an investigational irreversible FGFR1–4 inhibitor in development as a once-daily oral treatment for iCCA. Based on initial studies in multiple tumor types expressing FGFR abnormalities, iCCA was identified as a tumor type with potential susceptibility to FGFR inhibition and high unmet need. A phase I portion of the trial with an iCCA expansion cohort demonstrated tolerability and preliminary evidence of clinical efficacy with TAS-120 as a continuous, once-daily oral treatment in patients with iCCA. The most common AEs in the phase I portion of the trial were hyperphosphatemia, a mechanism-based on-target side effect, cutaneous AEs, and gastrointestinal AEs. The phase I portion of the study is continuing to enroll, and final results are anticipated in early 2019. Based on preliminary findings, a phase II portion of the study (FOENIX-101; clinicaltrials.gov registration NCT02052778) has been initiated. Methods: The phase II portion of the trial is a global, single-arm study of TAS-120 in patients with iCCA harboring FGFR2 gene rearrangements. The study will enroll approximately 100 adult patients with locally advanced or metastatic iCCA that progressed after ≥ 1 systemic therapies and with an ECOG PS of 0 or 1. Prior systemic therapy must include gemcitabine plus platinum-based chemotherapy. Screening for FGFR2 gene rearrangements will be performed at a central laboratory. The primary endpoint is objective response rate based on RECIST v1.1. Secondary endpoints include duration of response, disease control rate, overall survival, progression-free survival, safety, and health-related quality of life. Clinical trial information: NCT02052778.

TPS462 Background: Dysregulation of fibroblast growth factor receptor (FGFR) signaling by FGFR genetic alterations is implicated in many cancers, including cholangiocarcinoma (CCA). FGFR2 translocations with fusion partners occur in ≈10% to 20% of intrahepatic CCA tumors. Pemigatinib is a selective oral inhibitor of FGFR-1, 2, 3. Preliminary data from the ongoing phase 2 study show efficacy and tolerable safety in patients (pts) with CCA with FGFR2 translocations. We present the design for a phase 3, open-label, randomized trial investigating pemigatinib monotherapy versus gemcitabine plus cisplatin chemotherapy in the first-line treatment of pts with advanced/metastatic or unresectable CCA with FGFR2 rearrangement. Methods: Eligible pts (target, N = 432) are ≥ 18 years (≥ 20 years for Japanese pts) and have ECOG performance status ≤ 1 and histologically confirmed advanced (locally advanced, metastatic, or recurrent) CCA with a documented FGFR2 rearrangement. Key exclusion criteria include prior systemic therapy, excluding adjuvant/neoadjuvant treatment completed ≥ 6 months before enrollment; current evidence of clinically significant corneal or retinal disorder; history of calcium and phosphate homeostasis disorder or systemic mineral imbalance with ectopic calcification of soft tissues; and known, untreated CNS metastases or history of uncontrolled seizures. Pts are randomized 1:1 and stratified by geographic region and tumor burden into 2 treatment groups: pemigatinib starting dose 13.5 mg once daily continuously on a 3-week cycle; or gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) administered intravenously on days 1 and 8 of every 3-week cycle for up to 8 cycles until disease progression or unacceptable toxicity. Crossover to pemigatinib may be allowed once progressive disease is confirmed. The primary endpoint is progression-free survival (based on independent central review using RECIST v1.1). Secondary endpoints include overall response rate, overall survival, duration of response, disease control rate, safety and tolerability, and impact on quality of life. Clinical trial information: NCT03656536.

442 Background: Neutrophil to lymphocyte ratio (NLR) has been used as an inflammation-based prognostic marker for various malignancies. The aim of our study was to determine whether NLR can independently predict the overall survival in patients with metastatic gallbladder cancer (GBC). Methods: We identified patients diagnosed with GBC who were treated at Mayo Clinic between the years 2000 and 2016. Patients who had nonmetastatic GBC were excluded along with the patients who did not have data for neutrophils and lymphocytes. Optimal cutoff point for NLR was identified by plotting martingale residuals against NLR and patients were divided into two groups, ≥ 5 or < 5. Demographic, follow-up data and outcomes were collected by retrospective review of electronic medical records. Fisher’s exact test was used to compare categorical variables, while The Mann- Whitney U test was used to compare continuous variables. Kaplan-Meier curves were plotted for NLR ≥ 5 and NLR < 5 and overall survival (OS) between the two groups were compared using log rank test. Multivariate survival analysis was performed using Cox-proportional hazard regression. Results: A total of 231 patients met our inclusion criteria, of which, 138 (60%) had NLR < 5 and 93 (40%) had NLR ≥ 5. Patients with NLR ≥ 5 were more likely to be older and have poor performance score, lower albumin level, higher alkaline phosphatase level, and higher platelet count. There were no significant differences noted in gender, race and administration of chemotherapy between the two groups. In univariate analysis, patients with NLR ≥ 5 at presentation had a significantly worse OS compared to those with NLR < 5 (Median survival: 3.6 vs. 8.8 months, p < 0.001). In multivariate analysis, adjusting for age, ECOG status, albumin, ALP, AST, ALT, bilirubin, platelet count and administration of chemotherapy, NLR of ≥ 5 was associated with a worse OS compared to NLR < 5 (HR: 1.70, 95% CI:1.20 – 2.39. p < 0.05). Conclusions: Our study demonstrates that NLR ≥ 5 is an independent predictor of poor prognosis in patients with metastatic gallbladder cancer.

408 Background: Standard of care for CCA/GBC is C-G therapy. MAbs (ATZ, pembrolizumab) targeting PD-L1 show promise in treating CCA/GBC. Hyaluronan (HA), which may impede drug and immune cell access, is high (67%) in CCA/GBC tumors. PEGPH20 enzymatically degrades HA. HALO 110-101 (NCT03267940) evaluates safety and activity of PEG-C-G-ATZ or PEG-C-G versus C-G in CCA/GBC pts. Methods: This study comprises two parts. In Run-In (RI) six pts were enrolled in PEG-C-G arm, then six pts in PEG-C-G-ATZ arm. Eight additional pts may be enrolled for tolerability. In Expansion (EX), up to 50 pts will be enrolled for efficacy. Treatment (Tx) cycle is 21 days (d). PEGPH20 dose is 3 μg/kg on d1, eight and 15 and ATZ dose is 1200 mg (one–three hours after PEGPH20) on d1 (PEG-C-G-ATZ only). C-G is dosed at 25 mg/m2 C and 1000 mg/m2 G on d2 and nine. In C-G arm (EX only), C-G is dosed on d1 and 8. Primary endpoints are ORR (RECIST v1.1), AEs (NCI CTCAE v4.03), laboratory/safety (RI only); secondary endpoints are PK; DOR, DCR, PFS; OS, OS by PD-L1 expression; ORR and DOR (imRECIST). Results: Eighteen pts have been enrolled (nine in each arm). The mean (SD) age is 57 (12.2) yrs in PEG-C-G and 69 (8.8) yrs in PEG-C-G-ATZ. 56% were men. All pts experienced ≥ 1 AE. The most common AEs are nausea, fatigue (50% each); decreased appetite (44%); anemia, constipation (39% each); thrombocytopenia, oedema peripheral, AST increased, myalgia (33% each). To date, there has been one dose-limiting toxicity (febrile neutropenia) in the PEG-C-G arm. There have been no deaths due to AEs. Conclusions: The overall safety profile of PEGPH20 + C + G ± ATZ is acceptable and consistent with safety observed for the individual components. There were no DLTs resulting in a dose reduction of PEGPH20, which is being dosed at 3 μg/kg in the EX phase. Clinical trial information: NCT03267940. [Table: see text]

393 Background: Clinicopathological features and the outcomes of patients with fibrolamellar hepatocellular carcinoma (FLHCC) are not clearly defined. Methods: Data were collected by retrospective chart review on 42 patients with FLHCC treated between 1990 and 2017 at the Mayo Clinic. Clinicopathological characteristics, response to treatment, recurrence pattern and survival were analyzed. Results: Of 42 patients (17 males and 25 females; median age at diagnosis 22 years, range 15 to 39), 10 patients (23%) had stage I disease and 32 patients (77%) had stage II to IVB disease. All 10 patients with stage I disease and 21 of 32 patients with stage II-IVB disease underwent resection at presentation. In stage I patient group, 6 patients experienced recurrence with a median time to recurrence of 30.5 months, resulting in a 5 year overall survival (OS) of 86%. Patients with stage II to IVB disease who underwent resection (n=21) at presentation had a median OS of 32.5 months and 5 year OS of 44%. In the upfront surgery group, 71% of the patients experienced recurrent disease. The median OS of patients with unresectable disease (n=11) was 10 months. Systemic therapy was given to 17 patients which included sorafenib, FOLFOX (5-fluorouracil/leucovorin and oxaliplatin), gemcitabine plus oxaliplatin, single agent adriamycin or gemcitabine, capecitabine plus interferon alfa, gemcitabine plus cisplatin, cisplatin plus adriamycin and nivolumab . Sorafenib was given to 9 patients and 4 patients achieved stable disease (SD) with duration ranging from 5 months to 5 years. One programmed cell death receptor positive-1 patient had a durable complete response after 2 months of therapy with nivolumab. Conclusions: In FLHCC, surgical resection was associated with prolonged OS. However, recurrences were common after the surgery. Limited benefit was derived from the systemic treatment. In rare cases, therapy with a checkpoint inhibitor may provide a viable treatment option.

291 Background: Cholangiocarcinoma (CCA) has limited treatment options. Genomic analyses have led to development of targeted therapies now in clinical trials, and may enable discovery of new treatment options. However, biopsy often yields limited tissue, thus hampering tissue-based profiling opportunities. Comparative data regarding circulating tumor DNA (ctDNA) analysis and tissue based profiling in CCA are limited. Methods: We performed ctDNA NGS analysis along with tissue based profiling in pts with advanced CCA (January 2015- February 2018). ctDNA analysis was performed using Guardant 360 (Guardant Health, CA) which detects single nucleotide variants, amplifications, fusions, and specific insertion/deletion mutations in up to 73 different genes and the majority of tissue based profiling using Foundation One. The mutant allele fraction (MAF) for detected alterations was calculated relative to wild type in ctDNA. Therapeutic relevance was defined as alterations within OncoKB levels 1-3B and R1. The study was conducted in accordance with Mayo Clinic IRB requirements. Results: Among 124 pts and 139 total samples, ctDNA NGS revealed at least one genomic alteration (excluding variants of uncertain significance and synonymous mutations) in 89% of pts. Median number of alterations per pt was 3 [range, 1-15], with a median MAF of 0.42% (range, 0.1% - 94.2%). The total number of unique alterations was 321. The most commonly altered genes: TP53 (31%), KRAS (11%), FGFR2 (7%), APC and PIK3CA (each 5%) and ARID1A (3%). Amplifications were noted in 14 genes: BRAF, CCND1, CCND2, CCNE1, CDK4, CDK6, EGFR, ERBB2, FGFR1, FGFR2, MET, MYC, PDGFRA, and PIK3CA. Tissue-based profiling was available in 57 (46%) pts, with a median of 63 days between liquid and tissue biopsy. IDH1, FGFR2, TP53 and KRAS were most common gene mutations found in pts who had both liquid and tissue biopsy done. (Comparative results to be shown). Conclusions: ctDNA plasma profiling of pts with advanced CCA is a feasible alternative method to gather comprehensive genomic data. Further larger cohort studies comparing landscape of alterations seen on ctDNA versus tissue-based assays are needed.

289 Background: PDAC has limited treatment options. Genomic analyses have led to development of targeted therapies now in several clinical trials, and may enable the discovery of new treatment options. However, biopsy often yields limited tissue, thus hampering tissue-based profiling opportunities. Data regarding circulating tumor DNA (ctDNA) profiling in PDAC during real time clinical practice is limited. Methods: We performed ctDNA NGS analysis in pts with advanced PDAC (December 2014–August 2018). ctDNA analysis was performed using Guardant 360 (Guardant Health, CA), which detects single nucleotide variants, amplifications, fusions, and specific insertion/deletion mutations in up to 73 different genes. The mutant allele fraction (MAF) for detected alterations was calculated relative to wild type in ctDNA. Therapeutic relevance (TR) was defined as possible treatments within OncoKB levels 1-3B and R1. The study was conducted in accordance with Mayo Clinic Institutional Review Board requirements. Results: Among 171 pts and 206 total samples, ctDNA NGS revealed at least one genomic alteration in 150 pts (88%). Median number of alterations per patient was 3 [range, 1-15]. The total number of unique alterations was 450 with the most commonly altered genes being: TP53 (181 alterations, 40%), followed by KRAS (118 alterations, 26%), CDKN2A (23 alterations, 5%), SMAD4 (15 alterations, 3%), EGFR (11 alterations, 2.4%), PIK3CA (9 alterations, 2%), GNAS (8 alterations, 1.5%). Amplifications were noted in 16 genes, including BRAF, CCND2, CCNE1, CDK4, CDK6, EGFR, ERBB2, FGFR1, FGFR2, KIT, KRAS, MET, MYC, PDGFRA, PIK3CA and RAF1. Therapeutically relevant alterations were seen in 95 pts of the 150 pts (63%). Tissue based profiling (Results to be shown) was done in 56 (33%) pts of total 171 pts with a median of 130 days between ctDNA and tissue biopsy. KRAS and TP53 were the most common gene mutations found in patients with both liquid and tissue biopsy results. Conclusions: ctDNA plasma profiling of pts with advanced PDAC is a feasible alternative method to gather comprehensive genomic data.

236 Background: Hepatobiliary cancer (HBC), including cholangiocarcinoma, affects over 40,000 people in the U.S. each year, and results in over 30,000 cancer deaths annually. Despite continuing advances in next-generation sequencing (NGS), the understanding of germline genetic risk as it relates to these malignancies remains limited, and guidelines for the germline testing of these patients are lacking. We report the spectrum of pathogenic/likely pathogenic (P/LP) germline genetic variants observed in patients with HBC, and the clinical utility related to germline genetic test results. Methods: We retrospectively studied a consecutive series of 267 patients referred to Invitae for germline genetic testing based on a personal history of HBC, per an IRB approved protocol. Patients were evaluated with a multigene panel of up to 135 genes chosen by the ordering providers. De-identified clinical and family history information were reviewed as provided by clinicians. Results: Among 267 HBC patients 15% (n = 41) had P/LP variants identified in genes including MUTYH, ATM, CHEK2, BAP1, BRCA1, MLH1, BRCA2, PALB2, TP53, APC, CDH1, MSH6, and PMS2 (12% excluding MUTYH heterozygotes). Amongst patients with a family history (FH) of HBC, P/LP rate was 13%; for patients with a FH of cancers other than HBC, P/LP rate was 16%; for patients with no reported FH, P/LP rate was 13%. Conclusions: In this study, 15% of HBC patients had P/LP variants in cancer-risk genes. The clinical utility of these germline P/LP variants includes 32% of patients who were eligible for ongoing clinical treatment trials based on their germline test results (NCT02286687), 60% with clinical management recommendations per current NCCN guidelines, and cascade testing of at risk family members. These data justify comprehensive germline multigene panel testing in all HBC patients, in view of the potential impact on clinical management for a substantial fraction of positive patients as well as facilitating cascade testing for risk assessment of family members.