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In this randomized phase II study, we evaluated the efficacy and safety of sorafenib in combination with capecitabine and cisplatin (XP) as first-line chemotherapy in advanced gastric cancer.Patients with metastatic gastric or gastroesophageal junction adenocarcinoma were randomized (1:1) to receive either sorafenib plus XP (S + XP) or XP alone. In cases of disease progression in the XP arm, crossover to sorafenib alone was allowed. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), response rates, safety profiles, and biomarkers, and the response rates and PFS with secondline sorafenib alone after progression in the XP arm.Between Jan 2011 and Feb 2013, a total of 195 patients were accrued (97 in the S + XP arm and 98 in the XP alone arm). The overall response rate was 54% with S + XP, and 52% with XP alone (p = 0.83). With a median follow-up of 12.6 months (range, 0.1-29.2), the median PFS assessed by independent review was 5.6 months in the S + XP arm and 5.3 months in the XP arm (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.67-1.27, p = 0.61). Overall survival was not different between the two arms (median 11.7 vs. 10.8 months; HR 0.93, 95% CI 0.65-1.31, p = 0.66). Frequencies of grade 3/4 toxicities were similar between the S + XP and XP alone arms, except for neutropenia (21% vs. 37%), anorexia (0% vs. 5%), and hand-foot skin reaction (7% vs. 1%). Among 51 patients who crossed over to sorafenib alone after disease progression in the XP arm, there was no objective response and their median PFS was 1.3 months (95% CI, 1.2-1.7).The addition of sorafenib to XP chemotherapy was safe but not more effective than XP alone for first-line treatment of metastatic gastric cancer.

PURPOSE The combination of oxaliplatin and fluoropyrimidine for 6 months is one of the standard options for adjuvant therapy for high-risk stage II and III colorectal cancers (CRCs). The optimal duration of oxaliplatin to diminish neurotoxicity without compromising efficacy needs to be clarified. PATIENTS AND METHODS This open-label, randomized, phase III, noninferiority trial randomly assigned patients with high-risk stage II and III CRC to 3 and 6 months of oxaliplatin with 6 months of fluoropyrimidine groups (3- and 6-month arms, respectively). The primary end point was disease-free survival (DFS), and the noninferiority margin was a hazard ratio (HR) of 1.25. RESULTS In total, 1,788 patients were randomly assigned to the 6-month (n = 895) and 3-month (n = 893) arms, and 83.6% in the 6-month arm and 85.7% in the 3-month arm completed the treatment. The neuropathy rates with any grade were higher in the 6-month arm than in the 3-month arm (69.5% v 58.3%; P < .0001). The 3-year DFS rates were 83.7% and 84.7% in the 6-month and 3-month arms, respectively, with an HR of 0.953 (95% CI, 0.769 to 1.180; test for noninferiority, P = .0065) within the noninferiority margin. Among patients with stage III CRC treated by capecitabine plus oxaliplatin, the 3-year DFS of the 3-month arm was noninferior as compared with that of the 6-month arm with an HR of 0.713 (95% CI, 0.530 to 0.959; P = .0009). However, among patients with high-risk stage II and stage III CRC treated by infusional fluorouracil, leucovorin, and oxaliplatin, the noninferiority of the 3-month arm compared with the 6-month arm was not proven. CONCLUSION This study suggests that adding 3 months of oxaliplatin to 6 months of capecitabine could be considered an alternative adjuvant treatment for stage III CRC (ClinicalTrials.gov identifier: NCT01092481 ).

Background Loss of PTEN function leads to increased PI3Kβ signaling. AZD8186, a selective PI3Kβ/δ inhibitor, has shown anti-tumor activity in PTEN-deficient preclinical models. Although the combination of AZD8186 and paclitaxel was well tolerated, limited clinical efficacy was observed in advanced gastric cancer with PTEN loss. Methods In the phase Ib dose-escalation, subjects with advanced solid tumors received oral AZD8186 (60 mg or 120 mg; twice daily (BID); 5 days on/2 days off) plus intravenous paclitaxel (70 mg/m2 or 80 mg/m2; days 1, 8, and 15) every 4 weeks. In the phase II part, MRGC patients with PTEN loss or PTEN/PIK3CB gene abnormality were enrolled and received recommended phase II dose (RP2D) of AZD8186 plus paclitaxel. Primary endpoints were to determine maximum tolerated dose (MTD) and RP2D in phase Ib and 4-month progression-free survival (PFS) rate in phase II. Results In phase Ib, both MTD and RP2D were determined at paclitaxel 80 mg/m2 and AZD8186 120 mg BID. In phase II, 18 patients were enrolled [PTEN loss (n = 18) and PIK3CB mutation (n = 1)]. The 4-month PFS rate was 18.8% (3 of 16 evaluable patients) and further enrollment stopped due to futility. Conclusion Although the combination of AZD8186 and paclitaxel was well tolerated, limited clinical efficacy was observed. ClinicalTrials.gov Identifier: NCT04001569.

To evaluate the safety and effectiveness of aflibercept in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI) in Korean patients with metastatic colorectal cancer (mCRC) who progressed with oxaliplatin-containing regimen.This was a prospective observational study conducted at 22 sites across Korea between February 2018 and September 2019. Patients aged 19 years with a diagnosis of mCRC who were prescribed aflibercept plus FOLFIRI, after progression with an oxaliplatin-containing regimen were included. Disease assessment was performed every 6 weeks.A total of 185 patients were included (males, 58.9%; right-sided tumors, 23.8%; and ECOG performance factor ≥ 1, 68.6%). A total of 514 adverse events (AEs) occurred in 134 patients, of which 206 (49.2%; 95% CI 42.0%, 56.4%) events were considered as adverse drug reactions (ADRs), 172 unexpected AEs (49.7%; 95% CI 42.5%, 56.9%), and 53 serious AEs (22.2%; 95% CI16.2%, 28.2%). The most common serious ADR was pneumonia (n = 2, 1.6%). The most common all grade hematological AE and non-hematological AE were neutropenia (21.6%) and nausea (16.2%), respectively. Over a median follow-up of 5.6 months, a total of five grade 5 (1.0%) AEs were reported. Median OS was 9.4 months, and median progression-free survival (PFS) was 7.3 months. The overall response rate was 14.6%. Right-sided tumor location and prior bevacizumab treatment were independent factors of poor PFS in multivariate analysis.Aflibercept in combination with FOLFIRI was effective and showed an acceptable safety profile in Korean patients with mCRC in daily clinical practice.

A subgroup analysis of data from a nationwide study (KCSG-ST19-16) was performed to evaluate the efficacy and safety of second-line ramucirumab plus paclitaxel treatment in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastro-esophageal junction (GEJ) adenocarcinoma.The KCSG-ST19-16 study enrolled a total of 1063 patients from 56 hospitals in South Korea with advanced gastric or GEJ adenocarcinoma, who had received second-line treatment with ramucirumab plus paclitaxel. HER2 status was known for 994 (93.5%) of these patients, who were thus included in the subgroup analysis.In total, 163 of 994 patients (16.4%), had HER2-positive gastric or GEJ adenocarcinoma. The objective response rate to ramucirumab plus paclitaxel treatment was significantly higher in patients with HER2-positive disease compared to those with HER2-negative disease (23.0% [95% confidence interval (CI), 15.9-30.1] vs. 15.1% [95% CI, 12.3-17.9], p = 0.025). The median progression-free survival was longer in patients with HER2-positive versus HER2-negative disease, but the difference was not statistically significant (4.3 months [95% CI, 3.7-5.3] vs 3.7 months [95% CI, 3.4-4.0], p = 0.054). There was no statistically significant difference in median overall survival (OS) between the groups (9.8 months [95% CI, 8.9-12.3] vs 10.1 months [95% CI, 9.2-10.9], p = 0.564).In patients with HER2-positive gastric or GEJ adenocarcinoma, the objective response rate to second-line treatment with ramucirumab plus paclitaxel was significantly higher compared to patients with HER2-negative disease. However, an increased response to treatment was not associated with an improvement in OS.

Background The efficacy of modified FOLFIRINOX (mFOLFIRINOX) as a second-line chemotherapy treatment for metastatic pancreatic adenocarcinoma (mPAC), remains unclear. This multi-center randomised phase III trial aimed to elucidate the efficacy of mFOLFIRINOX as a second-line chemotherapy treatment for mPAC patients with good performance status. Patients and methods Eighty mPAC patients (age, 19–75 years) refractory to first-line gemcitabine-based chemotherapy were randomly selected to receive mFOLFIRINOX or S-1. mFOLFIRINOX comprised oxaliplatin (65 mg/m2), irinotecan (135 mg/m2), and leucovorin (400 mg/m2) on day 1 and continuous 5-FU infusion (1000 mg/m2) over 24 h on days 1–2 every 2 weeks. S-1 comprised body surface area-dependent oral S-1, divided into two doses per day on days 1–28 every 6 weeks. Results Overall survival was the primary endpoint. The objective response and disease control rates were higher in the mFOLFIRINOX than in the S-1 group (15% versus 2%; p = .04 and 67% versus 37%; p = .007). The median progression-free survival rates were 5.2 and 2.2 months in the mFOLFIRINOX and S-1 groups, respectively (adjusted hazard ratio [HR]: .4; 95% confidence interval [CI]: .2-.6; p Conclusion Administration of mFOLFIRINOX as a second-line chemotherapy treatment for mPAC patients refractory to gemcitabine-based chemotherapy resulted in increased survival rates than S-1 treatment alone.

PURPOSE Adjuvant chemotherapy after D2 gastrectomy is standard for resectable locally advanced gastric cancer (LAGC) in Asia. Based on positive findings for perioperative chemotherapy in European phase III studies, the phase III PRODIGY study (ClinicalTrials.gov identifier: NCT01515748 ) investigated whether neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) followed by surgery and adjuvant S-1 could improve outcomes versus standard treatment in Korean patients with resectable LAGC. PATIENTS AND METHODS Patients 20-75 years of age, with Eastern Cooperative Oncology Group performance status 0-1, and with histologically confirmed primary gastric or gastroesophageal junction adenocarcinoma (clinical TNM staging: T2-3N+ or T4Nany) were randomly assigned to D2 surgery followed by adjuvant S-1 (40-60 mg orally twice a day, days 1-28 every 6 weeks for eight cycles; SC group) or neoadjuvant DOS (docetaxel 50 mg/m2, oxaliplatin 100 mg/m2 intravenously day 1, S-1 40 mg/m2 orally twice a day, days 1-14 every 3 weeks for three cycles) before D2 surgery, followed by adjuvant S-1 (CSC group). The primary objective was progression-free survival (PFS) with CSC versus SC. Two sensitivity analyses were performed: intent-to-treat and landmark PFS analysis. RESULTS Between January 18, 2012, and January 2, 2017, 266 patients were randomly assigned to CSC and 264 to SC at 18 Korean study sites; 238 and 246 patients, respectively, were treated (full analysis set). Follow-up was ongoing in 176 patients at data cutoff (January 21, 2019; median follow-up 38.6 months [interquartile range, 23.5-62.1]). CSC improved PFS versus SC (adjusted hazard ratio, 0.70; 95% CI, 0.52 to 0.95; stratified log-rank P = .023). Sensitivity analyses confirmed these findings. Treatments were well tolerated. Two grade 5 adverse events (febrile neutropenia and dyspnea) occurred during neoadjuvant treatment. CONCLUSION PRODIGY showed that neoadjuvant DOS chemotherapy, as part of perioperative chemotherapy, is effective and tolerable in Korean patients with LAGC.

Background Dasatinib is administered at a fixed starting dosage of 100 mg once daily regardless of patient-specific factors. However, such fixed dosing may not be optimal for the treatment of Asian patients with chronic myeloid leukemia in chronic phase (CP-CML). Patients and Methods The dose-limiting toxicities (DLTs) and molecular responses (MRs) of dasatinib therapy were evaluated using clinical data obtained from 102 patients newly diagnosed with CP-CML at 17 hospitals in South Korea. Results By 36 months after the initiation of a fixed dose regimen of dasatinib 100 mg once daily as the first-line therapy, 55.9% of patients experienced at least one type of DLT. The 3 most frequent DLTs were thrombocytopenia (45.5%), pericardial or pleural effusion (30.9%), and anemia (7.3%). Patients with higher dasatinib dose adjusted for body weight (Dose/BW) had a greater rate of DLT occurrence (logit [P] = 1.58 × [Dose/BW] − 2.27, P = .03). As median Dose/BW increased from 1.23 to 2.00 mg/kg, the rate of DLT occurrence increased from 43.5% to 66.7% (P = .03). However, Dose/BW did not affect the achievement rate of major MR (60.9% to 69.6%, P = .92). Conclusion The starting dosage of dasatinib may need to be reduced (eg, 80 mg once daily or lower) for Asian patients with CP-CML, especially with lighter BW, to alleviate the risk of DLT occurrence without compromising the achievement of MR.

Both MET exon 14 skipping mutation (METex14SM) and high copy-number variation (CNV) lead to enhanced carcinogenesis; additionally, programmed-death ligand 1 (PD-L1) is often upregulated in cancers. In this study, we characterized the expression of MET (including METex14SM), PD-L1, and CD44 in human gastric cancer (GC) cells as well as the differential susceptibility of these cells to tepotinib. Tepotinib treatments inhibited the growth of five GC cells in a dose-dependent manner with a concomitant induction of cell death. Tepotinib treatments also significantly reduced the expression of phospho-MET, total MET, c-Myc, VEGFR2, and Snail protein in SNU620, MKN45, and Hs746T cells. Notably, tepotinib significantly reduced the expression of CD44 and PD-L1 in METex14SM Hs746T cells. By contrast, tepotinib was only slightly active against SNU638 and KATO III cells. Migration was reduced to a greater extent in the tepotinib-treated group than in the control group. Tepotinib may have therapeutic effects on c-MET-amplified GC, a high expression of both PD-L1 and CD44, and METex14SM. Clinical studies are needed to confirm these therapeutic effects.

Gastric cancer (GC), a prevalent malignancy in Eastern Asia, is associated with aberrant transcriptional regulation. Here, we evaluated the mRNA and microRNA transcriptomes in patients with gastric cancer to gain insight into the molecular underpinnings of this disease. We observed upregulation of inhibin βA (INHBA), CDC7, SULF1, COL11A1, KIAA1199, and CLDN1 transcripts in gastric cancer and showed that INHBA upregulation was associated with cancer recurrence. Expression of has-miR-135a-5p was significantly lower in gastric cancer tissues compared with matched normal tissues and was inversely associated with INHBA expression. Our findings suggest that INHBA and has-miR-135a-5p expression serve as therapeutic markers of gastric cancer recurrence.

Background: Abnormal regulation of genes has been closely related to gastric cancer. The characterization of gastric cancer has necessitated the development of new therapeutics as well as the identification of prognostic markers to predict the response to novel drugs. In our study, we used RNA sequencing analyses to show that on gastric cancer tissues to identification of gastric cancer prognostic markers. We specifically chose to study RNF43 because it inhibits gastric cancer-related Wnt/β-catenin signaling by interacting with Wnt receptors. PWWP2B was chosen because it is a gene which is downregulated in gastric cancer. Methods: Utilizing RNA sequencing analysis, we evaluated the mRNA expression profile in gastric cancer patients. Also, we used HAP1 cells which is a human near-haploid cell line derived from the male chronic myelogenous leukemia cell line KBM-7. These cell line has one copy of each gene, ensuring the edited allele will not be masked by additional alleles. We investigated the screening of 1,449 FDA-approved drugs in HAP1, HAP1 RNF43 KO and HAP1 PWWP2B KO cells. RNA sequencing data reveals that RNF43 and PWWP2B expression were down-regulated in recurrence gastric cancer patients. Next, we investigated the anti-cancer effects of selected drugs in RNF43 and PWWP2B down-regulated MKN45 gastric cancer cells and xenograft model. Results: Among these FDA-approved drugs, three drugs (docetaxel trihydrate, pelitinib and uprosertib) showed strong inhibitory effects in RNF43 KO cells and PWWP2B KO cells. In MKN45 xenograft model, tumor volumes were significantly reduced in the docetaxel trihydrate, uprosertib or pelitinib-treated group. Our data demonstrated that RNF43 and PWWP2B are a biomarker that predict recurrence of gastric cancer. Conclusions: Our findings suggest that docetaxel trihydrate, uprosertib and pelitinib could be used as novel therapeutic agents for the prevention and treatment of gastric cancer with a decrease in RNF43 and PWWP2B expression.

Tropomyosin receptor kinase (TRK) fusion is one of the oncogenic driver causes of colon cancer, and tropomyosin 3-neurotrophic receptor tyrosine kinase 1 (TPM3-NTRK1) fusion has been detected in the KM12SM cell line. In the present study, we investigated anticancer mechanisms in the KM12SM cell line using three different form of dovitinib (dovitinib (free base), dovitinib lactate (mono acid), and dovitinib dilactic acid (diacid)) and four TRK inhibitors (LOXO-101, entrectinib, regorafenib, and crizotinib). Exposure of TRK inhibitors at concentrations of 10 nM resulted in the apoptosis of KM12SM cells, whereas regorafenib had no effect. Treatment with all inhibitors except regorafenib also significantly increased the expression levels of the genes nuclear factor-erythroid 2-related factor 2 (NRF2) and glutamyl cysteine ligase catalytic subunit (GCLC) in KM12SM. These drugs significantly reduced expression of the phosphorylated proteins NFκB and COX-2 in the KM12SM cell line, and significantly attenuated KM12SM cell migration, according to a Transwell migration assay. Together, these results suggest that TRK inhibitors block products of carcinogenesis by negatively regulating the NFκB signaling pathway and positively regulating the antioxidant NRF2 signaling pathway.

Purpose CD44 isoforms are highly expressed in cancer stem cells, initiating tumor growth and sustaining tumor self-renewal. Among these isoforms, CD44 variant 9 (CD44v9) is overexpressed in chronic inflammation-induced cancer. CD44 and the mesenchymal-to-epithelial transition (MET) receptor tyrosine kinase are coactivated in some gastric cancers (GCs). In this study, we characterized MET and CD44 expression and signaling in human GC cell lines and analyzed differences in the susceptibility of these lines to foretinib. Patients and methods We analyzed cell viability and the rate of apoptotic cells using MTS assays and flow cytometry, respectively. Gene and protein expression were assessed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and immunoblotting, respectively. Results Foretinib treatment resulted in dose-dependent inhibition of growth in c-MET-amplified MKN45 and SNU620 cells with concomitant induction of apoptosis, but not in c-MET-reduced MKN28 and AGS cells. Foretinib treatment also significantly reduced phosphor-c-MET, phosphor-AKT, beta-catenin, and COX-2 protein expression in MKN45 and SNU620 cells. Interestingly, foretinib significantly reduced CD44, CD44v9, COX-2, OCT3/4, CCND1, c-MYC, VEGFA, and HIF-1a gene expression in CD44 and MET coactivated MKN45 cells and increased CD44s gene expression; in contrast, these drugs were only slightly active against SNU620 cells. Conclusion The results of this study indicate that foretinib could be a therapeutic agent for the prevention or treatment of GCs positive for CD44v9 and c-MET.

401 Background: Currently, ramucirumab plus paclitaxel is the standard second-line chemotherapy in metastatic gastric cancer (mGC), however, its efficacy is very limited. MSI, PD-L1 (CD274), and EBV have been suggested as predictive biomarkers for immune checkpoint inhibitors in mGC. This study was conducted to evaluate efficacy and safety of the combination of durvalumab, tremelimumab, and paclitaxel as a second-line chemotherapy in mGC with potential biomarkers for immune checkpoint inhibitors. Methods: The combination of durvalumab, tremelimumab, and paclitaxel consisted of 1500 mg of i.v. durvalumab on day 1, every 4 weeks for 13 cycles, 75 mg of i.v. tremelimumab on day 1 every 4 weeks for 4 cycles, and 60 mg/m2 of i.v. paclitaxel on days 1, 8, and 15, every 4 weeks until disease progression or unacceptable toxicities. Patients (pts) with MSI-high mGC, EBV-positive mGC, or mGC with CD274 amplification, mutations of mismatch repair or POL gene, or tumor mutation burden (TMB) >5/Mb were included in second-line setting. Results: Forty-eight pts were enrolled. Overall response rate (ORR) was 52.1% with complete response in 4 (8.3%) pts, partial response in 21 (43.8%), stable disease in 14 (29.2%), and progressive disease in 8 (16.7%), and with response not evaluable in 1 (2.0%). With a median follow-up of 18.0 months (range, 7.1-39.4), the median progression-free survival (PFS) and overall survival (OS) were 5.3 months (95% CI, 3.7-6.9) and 13.1 months (95% CI, 5.2-21.0 ), respectively. Compared to mGC with other genetic alterations (n=25), mGC with TMB >20/Mb or MSI-high mGC (n=23) tended to have a higher ORR (56.5% vs 48%), and a prolonged PFS (median 7.2 vs 4.5 months; 44.0 vs 20.8% at 1 year). The combination chemotherapy was generally well tolerable; treatment-related grade 3 or 4 adverse events with frequency >5% included only neutropenia (10.4%) and anemia (8.3%), and there was no treatment-related death. Conclusions: The combination chemotherapy of durvalumab, tremelimumab, and paclitaxel showed encouraging efficacy, especially in mGC with TMB >20/Mb or MSI-high mGC, as a second-line chemotherapy with manageable toxicities in biomarker-selected mGC. Clinical trial information: NCT03751761 .

BackgroundRegulatory T-cells (Treg) are essential in maintaining self tolerance, but they can also suppress anti-tumor immunity in the tumor microenvironment (TME). Treg are recruited into tumors by C-C motif chemokine ligand 17 (CCL17), and 22 (CCL22), which are produced by tumor cells and other cells in the TME. These chemokines serve as a ”homing signal” to Treg by binding to their cognate receptor, C-C chemokine receptor type 4 (CCR4), the predominant chemokine receptor on human Treg.1 2 3 FLX475, is an orally available and selective small-molecule antagonist of CCR4. In preclinical studies it has demonstrated potent inhibition of CCL17- and CCL22-induced CCR4-mediated chemotaxis, an increase in the intratumoral Teff/Treg ratio, and anti-tumor efficacy as a single agent and in combination with checkpoint inhibitors. In a first-in-human healthy volunteer study, the orally-available CCR4 antagonist was well tolerated, with solid safety profile. A receptor occupancy (RO) pharmacodynamic (PD) assay using peripheral blood Treg demonstrated the ability to safely achieve exposure levels predicted to maximally inhibit Treg recruitment into tumors.4 The proposed mechanism of action, pharmacokinetics (PK), PD, and safety profile of FLX475 have enabled the optimized design of an ongoing Phase 2 study to assess the safety, efficacy of FLX475 in combination with pembrolizumab in patients with advanced or metastatic gastric cancer.MethodsThis clinical trial is a Phase 2, open-label study to assess the safety and efficacy of FLX475 in combination with pembrolizumab in patients with advanced or metastatic gastric cancer (NCT04768686). Approximately 90 subjects may be enrolled across 2 cohorts to examine the safety and efficacy when administered 100mg PO QD of FLX475 with 200mg IV Q3W of pembrolizumab. In cohort 1, checkpoint inhibitor naïve Epstein-Barr Virus (EBV)-negative gastric cancer subjects who have progressed on at least 2 prior systemic treatments for advanced or metastatic gastric cancer will be enrolled, and in cohort 2, checkpoint inhibitor naïve EBV-positive gastric cancer subjects who had at least 1 prior systemic treatment for advanced or metastatic gastric cancer will be enrolled. Both EBV negative and positive gastric cancer are predicted to express high levels of CCR4 ligands and enriched in Treg (i.e. ‘charged tumor’). The study is planned initially as a 2-stage design for each cohort, and an interim analysis reviewing efficacy and safety results as well as available PK and PD data for both cohorts will be performed prior to stage 2.AcknowledgementsThanks to the patients, and to their families and caregivers for allowing us to be part of the journey.RAPT Therapeutics, Inc., South San Francisco, CA, USA is providing FLX475 for the study.Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA is providing pembrolizumab for the study.Trial RegistrationNCT04768686ReferencesTalay O, et al. Potent and selective C-C chemokine receptor (CCR4) antagonists potentiate anti-tumor immune responses by inhibiting regulatory T cells (Treg). J Immunother Cancer 2017;5(Suppl 2):P467 (SITC 2017).Curiel, Tyler J, et al. Specific recruitment of regulatory T cells in ovarian carcinoma fosters immune privilege and predicts reduced survival. Nature medicine 10.9 (2004):942–949.Nakayama et al. Selective induction of Th2-attracting chemokines CCL17 and CCL22 in human B cells by latent membrane protein 1 of Epstein-Barr virus. J Virol 2004 February; 78(4):1665–74.van Marle S, et al. Pharmacokinetics, pharmacodynamics, and safety of FLX475, an orally-available, potent, and selective small-molecule antagonist of CCR4, in healthy volunteers. J Immunother Cancer 2018;6(Suppl 1):P484 (SITC 2018).

Next-generation sequencing (NGS) is becoming essential in the fields of precision oncology. With implementation of NGS in daily clinic, the needs for continued education, facilitated interpretation of NGS results and optimal treatment delivery based on NGS results have been addressed. Molecular tumor board (MTB) is multidisciplinary approach to keep pace with the growing knowledge of complex molecular alterations in patients with advanced solid cancer. Although guidelines for NGS use and MTB have been developed in western countries, there is limitation for reflection of Korea’s public health environment and daily clinical practice. These recommendations provide a critical guidance from NGS panel testing to final treatment decision based on MTB discussion.

Background Poziotinib (HM781-36B) is an irreversible pan-HER tyrosine kinase inhibitor which targets EGFR, HER2, and HER4. This prospective, multicenter, open-label, phase I/II study determined the maximum tolerated dose (MTD) and evaluated the safety and efficacy of poziotinib combined with paclitaxel and trastuzumab in patients with HER2-positive advanced gastric cancer (GC). Methods Patients with HER2-positive GC previously treated with one line of chemotherapy received oral poziotinib (8 mg or 12 mg) once daily for 14 days, followed by 7 days off. Paclitaxel (175 mg/m2 infusion) and trastuzumab (8 mg/kg loading dose, then 6 mg/kg infusion) were administered concomitantly with poziotinib on day 1 every 3 weeks. Results In the phase I part, 12 patients were enrolled (7 at dose level 1, 5 at dose level 2). One patient receiving poziotinib 8 mg and 2 receiving poziotinib 12 mg had dose-limiting toxicities (DLTs); all DLTs were grade 4 neutropenia, one with fever. The most common poziotinib-related adverse events were diarrhea, rash, stomatitis, pruritus and loss of appetite. The MTD of poziotinib was determined to be 8 mg/day and this was used in the phase II part which enrolled 32 patients. Two patients (6.3%) had complete responses and 5 (15.6%) had partial responses (objective response rate 21.9%). Median progression-free survival and overall survival were 13.0 weeks (95% CI 9.8-21.9) and 29.5 weeks (95% CI 17.9-59.2), respectively. Conclusions The MTD of poziotinib combined with paclitaxel and trastuzumab was 8 mg/day. This combination yielded promising anti-tumor efficacy with manageable toxicity in previously treated patients with HER2-positive GC.

Objective Gastric cancer is more open related to genetic predisposition. In our RNA sequencing study on gastric cancer patients, Runt-related transcription factor-3 (RUNX3) expression was significantly down-regulated in gastric cancer. We showed that decreased levels of RUNX3 are significantly associated with c-MET (r = − 0.4216, P = 0.0130). In addition, c-MET expression is a candidate for targeted therapy in gastric cancer. Therefore, in the present study, the anti-cancer effects of the c-MET inhibitor on gastric cancer cells from positive or negative for c-MET amplification were evaluated. Results INC280 treatment inhibits growth of a c-MET-amplified MKN45 (RUNX3-positive) and SNU620 (RUNX3-negative) diffuse type cells. Then, INC280 showed the highest inhibition and apoptotic rates with the lowest IC50s in MKN45 cells but not in c-MET-reduced MKN28 (intestinal type) cells. We also showed that INC280 inhibits the WNT signaling pathway and SNAIL expression in MKN45 cells. The data indicate that INC280 could be used as therapeutic agents for the prevention or treatment of diffuse gastric cancer positive for c-MET amplification. Electronic supplementary material The online version of this article (10.1186/s13104-019-4163-x) contains supplementary material, which is available to authorized users.

Purpose The purpose of this study was to evaluate chemotherapy patterns and changes in quality of life (QOL) during first-line palliative chemotherapy for Korean patients with unresectable or metastatic/recurrent gastric cancer (GC). Materials and Methods Thiswas a non-interventional, multi-center, prospective, observational study of 527 patients in Korea. QOL assessments were conducted using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires (QLQ)-C30 and QLQ-STO22 every 3 months over a 12-month period during first-line palliative chemotherapy. The specific chemotherapy regimens were selected by individual clinicians. Results Most patients (93.2%) received combination chemotherapy (mainly fluoropyrimidine plus platinum) as their first-line palliative chemotherapy. The median progression-free survival and overall survival were 8.2 and 14.8 months, respectively. Overall, “a little” changes (differences of 5-10 points from baseline)were observed in some of the functioning or symptom scales; none of the QOL scales showed either “moderate” or “very much” change (i.e., ≥ 11 point difference from baseline). When examining the best change in each QOL domain from baseline, scales related to some aspects of functioning, global health status/QOL, and most symptoms revealed significant improvements (p < 0.05). Throughout the course of first-line palliative chemotherapy, most patients’ QOL was maintained to a similar degree, regardless of their actual response to chemotherapy. Conclusion This observational study provides important information on the chemotherapy patterns and QOL changes in Korean patientswith advanced GC. Overall, first-line palliative chemotherapy was found to maintain QOL, and most parameters showed an improvement compared with the baseline at some point during the course.

Purpose We conducted a randomized, multicenter, phase III trial to compare S-1 plus docetaxel (DS) with S-1 plus cisplatin (SP) as adjuvant chemotherapy for stage III gastric cancer patients. Materials and Methods Stage III gastric cancer patients who had received curative gastrectomy with D2 lymphadenectomy were randomized into equal groups to receive adjuvant chemotherapy of eight cycles of DS (S-1 70 mg/m2/day on days 1-14 plus docetaxel 35 mg/m2on days 1 and 8) every 3 weeks or SP (S-1 70 mg/m2/day on days 1-14 plus cisplatin 60 mg/m2on day 1) every 3 weeks. The primary endpoint was 3-year disease-free survival (DFS) rate. Results Between November 2010 and July 2013, 153 patients (75 patients to DS and 78 patients to SP) were enrolled from 8 institutions in Korea. After the capecitabine plus oxaliplatin was approved based on the CLASSIC study, itwas decided to close the study early. With a median follow-up duration of 56.9 months, the 3-year DFS rate between two groups was not significantly different (49.14% in DS group vs. 52.5% in SP group). The most common grade 3-4 adverse event was neutropenia (42.7% in DS and 38.5% in SP, p=0.351). SP group had more grade 3-4 anemia (1.3% vs. 11.5%, p=0.037), whereas grade 3-4 hand-foot syndrome (4.1% vs. 0%, p=0.025) and mucositis (10.7% vs. 2.6%, p=0.001) were more common in DS group. Fifty-one patients (68%) in DS group and 52 (66.7%) in SP group finished planned treatment. Conclusion Our findings suggest that SP or DS is an effective and tolerable option for patients with curatively resected stage III gastric cancer.

e16037 Background: Aberrant expression of MET involving MET exon 14 (METex14) alteration and high CNV, which leads to enhanced tumorigenesis. In addition, the PD-L1 (CD274) is often upregulated in cancers. This study characterized expressions of MET (including METex14 skipping mutation), PD-L1 and CD44 in human gastric cancer (GC) cell lines, and further characterized the differential susceptibility of these cell lines to tepotinib. Methods: We assessed the antitumor activity of tepotinib in GC cell lines. CNV analysis using targeted next-generation sequencing (NGS) techniques. The effect of tepotinib on cell viability (IC50), apoptotic cell death, migration, the PD-L1, CD44 and c-MET signaling were evaluated by MTS assay, flow cytometry, wound-healing assay, western blotting, and qRT-PCR. Results: Tepotinib treatment showed dose-dependent growth inhibition of c-MET-amplified SNU620, MKN45, Hs746T, SNU638 and KATO III cells with concomitant induction of apoptosis. Tepotinib treatment also significantly reduced expressions of phospho-c-MET, total c-MET, VEGFR2, Snail and c-Myc protein in SNU620, MKN45 and Hs746T cells. Especially, tepotinib significantly reduced the expressions of CD44 and PD-L1 in METex14 skipping mutated Hs746T cells. In contrast, this drug was only slightly active against KATO III and SNU638 cells. Migrations were more reduced in the tepotinib-treated group than in the control group. Conclusions: These data show the possibility that tepotinib may have therapeutic effects in c-MET-amplified GC and both high PD-L1 expression and an MET exon 14 skipping mutation, suggesting that clinical studies need to confirm the therapeutic effect.

4001 Background: To explore proper agents for AGC patients as 2nd-line treatment based on optimal biomarker, we conducted K-Umbrella GC study with standard of care (SOC) controlled umbrella trial design. Methods: HER2-negative AGC patients from 6 Korean cancer centers were centrally screened for druggable targets by IHC and in situ hybridization. Patients were randomized to the biomarker vs. control group with SOC as 4:1 ratio. In the biomarker group, patients were treated with specific targeted agents in combination with weekly paclitaxel; 1) EGFR 2+/3+ patients for pan-ERBB inhibitor (afatinib; EGFR cohort), 2) PTEN loss/null (H-score

Tivantinib has been described as a selective inhibitor of c-Met and is being studied in various types of cancer. In this study, we evaluated the effects of tivantinib on the suppression of gastric cancer (GC) cell migration and apoptosis. We also examined the mechanism of action of tivantinib by oncogenic pathway analysis. We applied an RNA-sequencing approach in 34 GC patients to identify oncogenes that are differentially expressed in GC tissues. To examine the inhibitory effect of tivantinib on GC cells, we conducted apoptosis analysis using an annexin V-APC/PI apoptosis detection kit and trans-well migration assay with human GC cell lines. For oncogenic pathway analysis, Western blot and quantitative real-time PCR analysis were used to detect the expression of proteins and genes before and after tivantinib exposure. In the RNA-sequencing analysis of 34 GC patients, c-Met and VEGFA genes were expressed and positively correlated with each other. Cell migration and apoptosis analysis demonstrated that tivantinib induced the best inhibition effect in SNU620, MKN45 (carries VEGFB mutation), AGS, and MKN28 cells, but not in KATO III (carries VEGFB and VEGFC mutations) cells. Oncogenic pathway analysis showed that tivantinib, in addition to c-Met signaling pathway inhibition, also inhibits VEGF signaling and MYC expression in VEGFA-expressing GC cells. We found that tivantinib has anti-cancer activity not only in GC cells overexpressing c-Met but also in non-c-Met GC cells by inhibition of the VEGF signaling pathway.

330 Background: HER-RAM study is the phase Ib/II multicenter study to evaluate the safety and efficacy of adding trastuzumab to ramucirumab and paclitaxel as a second-line treatment in HER2-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer progressed from trastuzumab containing chemotherapy. We report survival follow up and exploratory biomarker results. Methods: Patients with HER2-positive advanced G/GEJ cancer who progressed after first-line trastuzumab containing chemotherapy were enrolled. Trastuzumab 4mg/kg on day 1 followed by 2mg/kg on days 8, 15, and 22, ramucirumab 8mg/kg on days 1 and 15, and paclitaxel (dose level 1: 80mg/m2, dose level -1: 70 mg/m2) on days 1, 8, and 15 of a 28-day cycle was tested. After safety analysis of lead-in safety cohort (phase 1b), phase 2 part was conducted to evaluate the primary endpoint of progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. Results: No dose limiting toxicity at the dose level 1 was observed at the phase Ib part, the dose level 1 with full dose combination was determined as recommended phase 2 dose. At the time of data lock on September 7th, 2021, 50 patients including 3 patients from the phase 1b part were evaluable for response and safety. Median age was 60 years old (range 29-82) and most patients were male (40/50). At baseline, 39 patients had tumors with HER-2 3+ by immunohistochemistry (IHC) and 11 had those with HER-2 2+ by IHC with ERBB2 amplification by in situ hybridization. With median follow-up duration of 18.8 months, median PFS and OS were 7.0 months (95% confidence interval [CI]: 4.9-9.2 months) and 13.6 months (95% CI: 9.5-17.6 months), respectively. ORR was 54% (27/50, complete response = 1, partial response = 26) and DCR was 96% (48/50), respectively. On the exploratory analysis, HER-2 positivity of tumor tissue was lost after fist-line chemotherapy in 8 of 23 patients (34.7%) without any definite association between loss of HER-2 and outcomes. Most common hematologic adverse event (AE) was neutropenia (all grade: 64%, grade 3/4: 52%) with 1 case of febrile neutropenia (2%). Most common non-hematologic AE was peripheral sensory neuropathy and anorexia (all grade: 32%, grade 3: 2%, respectively). Gastrointestinal (GI) bleeding occurred in 6 cases (grade 3 upper GI bleeding: 3 patients, grade 1/2 lower GI bleeding: 3 patients), whereas GI perforation was not observed. Hypertension occurred in 3 patients (grade 1/2: 1 patient, grade 3: 2 patients). No new or unexpected AEs were observed. Conclusions: The continuous use of trastuzumab in combination with ramucirumab and paclitaxel showed promising activity and manageable safety profile in HER2-positive G/GEJ cancer patients who progressed after trastuzumab containing chemotherapy. Clinical trial information: NCT04888663.

Radotinib is a second‐generation BCR‐ABL1 tyrosine kinase inhibitor approved for the treatment of chronic myeloid leukemia in chronic phase (CP‐CML). Here, using the data from a Phase 3 study conducted in patients with newly diagnosed CP‐CML, the dose–efficacy as well as dose–safety relationship analyses were performed to determine a safe and effective initial dosage regimen of radotinib. A significant positive association was detected between the starting dose of radotinib adjusted for body weight (Dose/BW) and the probability of dose‐limiting toxicity (≥grade 3 hematologic and nonhematologic toxicity) (P = 0.003). In contrast, a significant inverse association was discovered between Dose/BW and the probability of major molecular response (BCR‐ABL1/ABL1 ≤ 0.1%) when controlled for sex (P = 0.033). Moreover, frequent dose interruptions and reductions secondary to radotinib toxicities occurred in the Phase 3 study, resulting in nearly half (44%) of patients receiving a reduced dose at a 12‐month follow‐up. In conclusion, the results of this study demonstrate the need for initial radotinib dose attenuation to improve the long‐term efficacy and safety of radotinib. Hence, the authors suggest a new upfront radotinib dose of 400 mg once daily be tested in patients with newly diagnosed CP‐CML.

Purpose: Radotinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor (TKI) approved in Korea for chronic phase chronic myeloid leukemia (CML-CP) in patients newly diagnosed or with insufficient response to other TKIs. This study was conducted to evaluate the efficacy and safety of radotinib as first-line therapy for CML-CP. Experimental Design: This multinational, open-label study assigned patients (1:1:1) to one of two twice-daily radotinib doses, or imatinib daily. The primary endpoint was major molecular response (MMR) by 12 months. Results: Two hundred forty-one patients were randomized to receive radotinib 300 mg (n = 79) or 400 mg twice-daily (n = 81), or imatinib 400 mg daily (n = 81). MMR rates by 12 months were higher in patients receiving radotinib 300 mg (52%) or radotinib 400 mg twice-daily (46%) versus imatinib (30%; P = 0.0044 and P = 0.0342, respectively). Complete cytogenetic response (CCyR) rates by 12 months were higher for radotinib 300 mg (91%) versus imatinib (77%; P = 0.0120). Early molecular response at 3 months occurred in 86% and 87% of patients receiving radotinib 300 mg and radotinib 400 mg, respectively, and 71% of those receiving imatinib. By 12 months, no patients had progression to accelerated phase or blast crisis. Most adverse events were manageable with dose reduction. Conclusions: Radotinib demonstrated superiority over imatinib in CCyR and MMR in patients newly diagnosed with Philadelphia chromosome–positive CML-CP. This trial was registered at www.clinicaltrials.gov as NCT01511289. Clin Cancer Res; 23(23); 7180–8. ©2017 AACR.

Purpose We compared two induction regimens, idarubicin (12 mg/m2/d for 3 days) versus high-dose daunorubicin (90 mg/m2/d for 3 days), in young adults with newly diagnosed acute myeloid leukemia (AML). Patients and Methods A total of 299 patients (149 randomly assigned to cytarabine plus idarubicin [AI] and 150 assigned to cytarabine plus high-dose daunorubicin [AD]) were analyzed. All patients received cytarabine (200 mg/m2/d for 7 days). Results Complete remission (CR) was induced in 232 patients (77.6%), with no difference in CR rates between the AI and AD arms (80.5% v 74.7%, respectively; P = .224). At a median follow-up time of 34.9 months, survival and relapse rates did not differ between the AI and AD arms (4-year overall survival, 51.1% v 54.7%, respectively; P = .756; cumulative incidence of relapse, 35.2% v 25.1%, respectively; P = .194; event-free survival, 45.5% v 50.8%, respectively; P = .772). Toxicity profiles were also similar in the two arms. Interestingly, overall and event-free survival times of patients with FLT3 internal tandem duplication (ITD) mutation were significantly different (AI v AD: median overall survival, 15.5 months v not reached, respectively; P = .030; event-free survival, 11.9 months v not reached, respectively; P = .028). Conclusion This phase III trial comparing idarubicin with high-dose daunorubicin did not find significant differences in CR rates, relapse, and survival. Significant interaction between the treatment arm and the FLT3-ITD mutation was found, and high-dose daunorubicin was more effective than idarubicin in patients with FLT3-ITD mutation.

BACKGROUND Irinotecan-based chemotherapy is a standard backbone of therapy in patients with metastatic colorectal cancer (CRC) or gastric cancer (GC). However, there is still a paucity of information concerning the efficacy and safety of irinotecan-based regimens in elderly patients. PATIENTS AND METHODS Using the patient cohort (n = 1,545) from the UGT1A1 genotype study, we compared the efficacy and safety between elderly and nonelderly patients with metastatic CRC (n = 934) or GC (n = 611) who received first- or second-line FOLFIRI (irinotecan, leucovorin, and 5-fluorouracil) chemotherapy. RESULTS Despite lower relative dose intensity in elderly patients, progression-free survival and overall survival were similar between elderly (age ≥70 years) and nonelderly (

Anaplastic lymphoma kinase (ALK) fusion events lead to constitutive activation of the ALK kinase domain, thereby functioning as oncogenic drivers. These fusion proteins have been identified in numerous cancers. Crizotinib, a small molecule inhibitor of c-Met and ALK, is a Food and Drug Administration-approved drug with reported efficacy in the treatment of cancer. Tropomyosins (TPMs) are a family of actin filament-binding proteins. Altered TPM expression has been found in a variety of human tumors. Inhibitors of cancer-associated TPMs and actin-targeting compounds have been developed, but anti-actin agents have cardiac and respiratory muscle toxicities. In this study, we investigated the sensitivities of human TPM4 (hTPM4), human ALK (hALK), and their fusion gene (hTPM4-hALK) to crizotinib by measuring the lifespan of transgenic Drosophila. Flies overexpressing hTPM4-hALK, hTPM4 and hALK showed decreased lifespans compared with controls. Although crizotinib is an inhibitor of ALK, treatment with crizotinib significantly extended the lifespans of Drosophila expressing hTPM4 and hTPM4-hALK but had no effect on hALK-expressing flies. Autophosphorylation of Tyr1278 is necessary for full activation of the ALK domain. We confirmed that hTPM4-hALK was phosphorylated at Tyr1278 in a ligand-independent manner, and hTPM4-hALK-expressing flies treated with crizotinib showed a decreased level of Tyr1278 phosphorylation compared with untreated hTPM4-hALK-expressing flies, with a greater decrease induced by 1 µM compared with 200 nM crizotinib. Taken together, the results suggest that crizotinib is effective for treating ALK-driven cancer and might be a new therapeutic drug, without cardiac or respiratory muscle toxic effects, for TPM4-expressing cancers., Summary: In this study, we find that crizotinib extends the lifespan of Drosophila overexpressing hTPM4-ALK and hTPM4, which are linked with a variety of human tumors.

Myelodysplastic syndromes (MDS) with basophilia or eosinophilia are very rare and portend poor prognoses. We present a rare patient who had MDS with excess blasts as well as peripheral basophilia and concurrent bone marrow (BM) basophilia/eosinophilia. She had a complex karyotype including 5q and 7q deletions; however, no oncogenic mutations were observed on next-generation sequencing of 54 genes known to be frequently mutated in acute myeloid leukemia/MDS. Peripheral basophilia resolved after decitabine treatment. Ours is the first report to describe a genome-wide analysis and the use of decitabine to successfully treat basophilia in an MDS patient with concurrent BM basophilia/eosinophilia.

4119 Background: Modified FOLFIRINOX (mFOLFIRINOX) consisting of 5-fluorouracil/leucovorin, irinotecan, and oxaliplatin has been assessed as second-line treatment of patients with advanced pancreatic cancer in retrospective and phase II studies. However, the result was not confirmed by randomized controlled trial. Methods: A randomized, open-label, phase III trial was conducted at 9 institutions in Korea. Patients with metastatic pancreatic adenocarcinoma (mPAC) and Eastern Cooperative Oncology Group performance status of 0-1 who failed to first-line gemcitabine-based chemotherapy were randomly assigned to receive mFOLFIRINOX or S-1. The primary endpoint was overall survival. Results: A total of 80 patients were enrolled from March 2017 to December 2019. The accrual of patients was early terminated due to clear difference of efficacy in the interim analysis and expectation of poor recruitment due to conflicting adjuvant regimens. Objective response and disease control rates were 15.4% vs. 2.4% ( p= 0.041) and 66.7% vs. 36.6% ( p= 0.007) in the mFOLFIRINOX and S-1 arms, respectively. The median progression-free survival was 5.2 and 2.2 months in the mFOLFIRINOX and S-1 arms, respectively ( p= 0.002). The median overall survival was 9.2 and 4.9 months in the mFOLFIRINOX and S-1 arms, respectively ( p= 0.048). The adjusted hazard ratio of the mFOLFIRINOX arm to the S-1 arm for overall survival was 0.402 (95% confidence interval 0.223-0.725, p= 0.002). All grade 3-4 adverse events occurred in 56.5% and 17.1% in the mFOLFIRINOX and S-1 arms, respectively ( p< 0.001). However, only one patient in each arm prematurely discontinued treatment due to toxicity and there was no treatment-related mortality in both arms. Minimally important differences in the health-related quality of life were not observed in both arms. Conclusions: mFOLFIRINOX as second-line treatment in mPAC patients failed to gemcitabine-based chemotherapy demonstrated a survival benefit versus S-1 alone with acceptable toxicities. Clinical trial information: KCT0003534.

4063 Background: We evaluated the safety and efficacy of adding trastuzumab to ramucirumab and paclitaxel (TRP) as a second line treatment in human epidermal growth factor receptor 2 (HER-2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer progressed from trastuzumab containing chemotherapy. Methods: Patients with HER-2-positive advanced G/GEJ cancer who progressed after first-line chemotherapy with trastuzumab in combination with fluoropyrimidine and platinum were eligible. Trastuzumab (Herzuma[CT-P6], Celltrion Inc.) 4mg/kg on day 1 followed by 2mg/kg on days 8, 15, and 22, ramucirumab 8mg/kg on days 1 and 15, and paclitaxel (dose level 1: 80mg/m2, dose level -1: 70 mg/m2) on days 1, 8, and 15 of a 28-day cycle was tested. After safety analysis of lead-in safety cohort (phase 1b), phase 2 part was conducted to evaluate the primary endpoint of progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. Results: At the phase 1b part, as there was no dose limiting toxicity in 3 patients at the dose level 1, dose level 1 with full dose combination was determined as recommended phase 2 dose. At the time of data lock on Jan. 31, 2021, 45 patients among enrolled 50 patients were evaluable for response and safety including 3 patients from phase 1b part. Median age was 59 years old (range 30-82) and most patients were male (37/45). At baseline, 33 patients had tumors with HER-2 3+ by immunohistochemistry (IHC) and 12 had those with HER-2 2+ by IHC with ERBB2 amplification by in situ hybridization. With median follow-up duration of 11.6 months, median PFS and OS were 7.2 months (95% confidence interval [CI]: 6.0-8.5 months) and 13.6 months (95% CI: 10.3-16.9 months), respectively. ORR was 55.6% (25/45, complete response = 1, partial response = 24) and DCR was 95.6% (43/45), respectively. Most common hematologic adverse event (AE) was neutropenia (all grade: 64.4%, grade 3/4: 51.1%) with 1 case of febrile neutropenia (2.2%). Most common non-hematologic AE was peripheral sensory neuropathy (all grade: 33.3%, grade 3: 2.2%). Gastrointestinal (GI) bleeding occurred in 4 patients (grade 3 upper GI bleeding: 6.7%, grade 1 lower GI bleeding: 2.2%), whereas GI perforation was not observed. Hypertension occurred in 3 patients (all grade: 6.7%, grade 3: 4.4%). No new or unexpected AEs resulting in treatment cessation were observed with this combination regimen. Conclusions: The continuous use of trastuzumab beyond progression in combination with ramucirumab and paclitaxel showed promising activity and manageable safety profile in HER2 positive G/GEJ cancer patients who progressed after trastuzumab containing chemotherapy. Updated outcomes for ongoing patients will be presented.

4056 Background: Ramucirumab as monotherapy or in combination with paclitaxel is a second-line treatment option recommended for patients with locally advanced unresectable or metastatic gastroesophageal junction (GEJ) or gastric adenocarcinoma. However, real-world data of large samples focused on ramucirumab plus paclitaxel in gastric cancer are limited. We conducted a nationwide retrospective study to evaluate the efficacy, safety, and factors potentially associated with survival in patients with gastric or GEJ adenocarcinoma who received second-line ramucirumab plus paclitaxel in a real-world setting. Methods: The study population comprised all patients with gastric or GEJ cancer who received ramucirumab plus paclitaxel in South Korea between May 1, 2018, and December 31, 2018. We included patients with advanced gastric or GEJ adenocarcinoma and disease progression after first-line platinum and fluoropyrimidine-containing combination chemotherapy. Results: A total of 1,063 patients with advanced gastric or GEJ adenocarcinoma who received ramucirumab plus paclitaxel were included. The objective response rate and disease control rate were 15.1% and 57.7%, respectively; the median progression-free survival was 4.03 months (95% CI, 3.80–4.27), and the median overall survival was 10.3 months (95% CI, 9.33–10.73). The common treatment-related adverse events (TRAEs) at any grade were neutropenia (44.7%), anemia (41.8%), neuropathy (29.1%), fatigue (25.9%), and anorexia (25.0%). Grade 3 or higher TRAEs with incidences of ≥5% were neutropenia (35.1%) and anemia (10.5%). Adverse events of special interest were infrequent, including hypertension (2.1%) and proteinuria (3.0%). Based on multivariate analysis, overall survival was negatively associated with Eastern Cooperative Oncology Group performance status ≥2, weight loss in the previous 3 months ≥10%, GEJ of primary tumor, poor or unknown histology grade, number of metastatic sites ≥3, presence of peritoneal metastasis, no prior gastrectomy, and time to second-line since first-line treatment < 6 months. Conclusions: Our large-scale, nationwide, real-world data analysis of an unselected real-world population added evidence for the efficacy and safety of second-line ramucirumab plus paclitaxel in patients with locally advanced unresectable or metastatic gastric or GEJ adenocarcinoma. Clinical trial information: NCT04192734.

218 Background: We report the updated clinical data and molecular profiling results of a multi-institutional phase Ib/II trial of triple combination (pembrolizumab, trastuzumab, and chempotherapy) as first line therapy for HER2 positive advanced gastric and gastroesophageal junction (AGC/GEJ) cancer. (PANTHERA trial; NCT02901301). Methods: Pembrolizumab 200mg IV D1, Trastuzumab 6mg/kg (after 8mg/kg load) D1, Capecitabine 1000mg/m2 bid D1-14, and Cisplatin 80mg/m2 D1 every 3 weeks was selected as recommended phase II dose. The primary endpoint for phase II was ORR per RECIST v1.1. Secondary endpoints included PFS, OS, DOR, safety, and predictive biomarker analysis by targeted NGS. Results: At the time of data lock on Aug 31, 2020, total of 43 patients were treated with median follow up of 18.2 months, and 3 patients remained on the treatment, and 6 patients finished 2-year treatment without progression. ORR was 76.7% (CR 16.3%, PR 60.5%, conversion surgery 4.6%) with 26 pts (56.6%) showing more than 50% of tumor burden reduction. Median PFS was 8.6 months (95% CI 7.2-16.5) and median OS was 19.3 months (95% CI 16.5-NR). There were no MSI-H/dMMR or EBV-positive pts. No patient discontinued pembrolizumab because of immune-related adverse events. Clinical features including PD-L1 status (55.3% of pts ≥ CPS 1 and 13.2% of pts ≥ CPS 10 among available 38 pts), metastatic organ or baseline tumor burden was not related to the survival. Ninety-eight tumor tissues from 39 pts (paired tumor tissues from 22 pts) were analyzed with targeted NGS. Although every pts were HER2 IHC-positive, baseline HER2 amplification by NGS was related to the survival ( HER2 amp (n=8) vs HER2 non-amp (n=23); mPFS, not reached vs 7.7 months, P=0.0178; mOS, not reached vs 17.9 months, P=0.044) but no other signaling pathways predicted pts’ survival. HER2 mutations including L869R or D769H were related to the acquired resistance. High TMB showed a tendency toward better survival (mPFS; High (n=7) vs Low (n=24) TMB, 22.0 vs 8.2, P=0.2835) due to small number of patients. Updated immune markers and serial NGS analyses will be presented. Conclusions: First-line triplet regimen (Pembrolizumab, Trastuzumab, and Chemotherapy) showed promising efficacy based on HER2 amplification by NGS regardless of PD-L1 status in AGC/GEJ cancer. Correlative biomarkers found from NGS study need to be validated through on-going phase III Keynote-811 study. Clinical trial information: NCT02901301. [Table: see text]

Aberrant expression of mucins (MUCs) can promote the epithelial&ndash, mesenchymal transition (EMT), which leads to enhanced tumorigenesis. Carcinogenesis-related pathways involving c-MET and &beta, catenin are associated with MUCs. In this study, we characterized the expression of EMT-relevant proteins including MET, &beta, catenin, and E-cadherin in human gastric cancer (GC) cell lines, and further characterized the differential susceptibility of these cell lines compared with the c-MET inhibitor tepotinib. We assessed the antitumor activity of tepotinib in GC cell lines. The effects of tepotinib on cell viability, apoptotic cell death, EMT, and c-MET and &beta, catenin signaling were evaluated by 3-(4,5 dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl)-2H-tetrazolium (MTS), flow cytometry, Western blotting, and qRT-PCR. The antitumor efficacy was assessed in MKN45 xenograft mice. Tepotinib treatment induced apoptosis in c-MET-amplified SNU620, MKN45, and KATO III cells, but had no effect on c-MET-reduced MKN28 or AGS cells. Tepotinib treatment also significantly reduced the protein levels of phosphorylated and total c-MET, phosphorylated and total ERK, &beta, catenin, and c-MYC in SNU620 and MKN45 cells. In contrast, this drug was only slightly active against KATO III cells. Notably, tepotinib significantly reduced the expression of EMT-promoting genes such as MMP7, COX-2, WNT1, MUC5B, and c-MYC in c-MET-amplified GC cells and increased the expression of EMT-suppressing genes such as MUC5AC, MUC6, GSK3&beta, and E-cadherin. In a mouse model, tepotinib exhibited good antitumor growth activity along with increased E-cadherin and decreased phosphorylated c-MET (phospho-c-MET) protein levels. Collectively, these results suggest that tepotinib suppresses tumor growth and migration by negatively regulating c-MET-induced EMT. These findings provide new insights into the mechanism by which MUC5AC and MUC6 contribute to GC progression.

3081 Background: Combining anti-PD-1 agent and trastuzumab has shown synergy in HER2 positive preclinical cancer models. We first report the result of a multi-institutional phase Ib/II trial of triple combination (pembrolizumab, trastuzumab, and chempotherapy) as first line therapy for HER2 positive AGC. (PANTHERA trial; NCT02901301). Methods: Pembrolizumab 200mg IV D1, Trastuzumab 6mg/kg (after 8mg/kg load) D1, Capecitabine 1000mg/m2 bid D1-14, and Cisplatin 80mg/m2 D1 every 3 weeks was selected as recommended phase II dose. The primary endpoint for phase II was ORR per RECIST v1.1. Secondary endpoints included PFS, OS, DoR, safety, and molecular analysis by targeted NGS. Results: Total of 43 patients were treated with median follow up of 16.1 months, and 11 pts remained on the treatment (treatment duration range: 1.4 to 24 months). There was significant tumor shrinkage of 95.3% with 54.6% median depth of response, with 76.7% ORR (CR 16.3%, PR 60.5%, conversion surgery 4.6%), and 97.7% DCR. Median PFS was 8.6 months (95% CI 7.2-22.0) and median OS was 18.4 months (95% CI 17.9-NA). Subsequent chemotherapy was given to 83.3% of 30 progressed pts. There were no MSI-H/dMMR or EBV-positive pts. PD-L1 status (57.1% of pts ≥ CPS 1 and 14.3% of pts ≥ CPS 10 among 35 pts), metastatic organ or baseline tumor burden was not related to the survival. Treatment-related AE (≥G3) occurred in 32 pts (74.4%) including 17 pts (39.5%) with neutropenia G3-4. Immune-related AEs (≥G3) occurred in 4 pts (10%). Ninety-six tumor tissues from 32 pts (paired tumor tissues from 25 pts) were analyzed with targeted NGS. TMB (median 12.7 mut/MB with range of 9.45-16.71) was not related to the PD-L1 expression or survival. Conclusions: First-line triplet regimen (Pembrolizumab, Trastuzumab, and Chemotherapy) confers a significant tumor shrinkage for HER2 positive AGC, regardless of PD-L1 status. Phase III Keynote-811 study (NCT03615326) is ongoing based on the protocol of this study. Clinical trial information: NCT02901301 . [Table: see text]

4551 Background: Neoadjuvant or perioperative chemotherapy has been accepted as a standard treatment globally in patients (pts) with locally advanced gastric cancer (LAGC). In PRODIGY phase III study (n = 530), we have demonstrated that neoadjuvant chemotherapy with DOS regimen (docetaxel, oxaliplatin, S-1) led to significant tumor downstaging and improved PFS in Korean LAGC pts (Kang, et al. ESMO 2019). Although CT has been performed to re-stage the tumor after neoadjuvant chemotherapy, there has been a relative paucity of diagnostic accuracy data. This study is to evaluate the diagnostic performance of restaging of LAGC after neoadjuvant chemotherapy using CT in PRODIGY study population. Methods: Of 266 pts, who had been diagnosed LAGC of T2-4 or N+ stage as assessed with CT and randomized to neoadjuvant chemotherapy arm (CSC) in PRODIGY study, 214 pts underwent gastrectomy were included in this analysis. The post-chemotherapy T- and N- stage was determined based on CT scan taken just prior to surgery and compared with the pathologic stage (AJCC 7th edition). Two experienced radiologists independently evaluated depth of primary tumor and reached consensus if any discrepancy between two readers. Diameter of short axis of the largest regional lymph node was measured to predict metastatic lymph node. Result of histopathologic T- and N-staging using surgical specimen was used as reference standard. Results: The study cohort consisted of pathologic T0 (n = 22), T1(n = 39), T2(n = 31), T3(n = 79), and T4(n = 43). The overall diagnostic accuracy of CT was 45%. For each T-stage, accuracy of T0,T1,T2,T3, and T4 was 0%, 26%, 29%, 55% and 79%, respectively. Rate of over- and under- staging was 47% and 8%, respectively. Accuracy for prediction of downstaging to early gastric cancer (T0-T1) was 83%. Interobserver agreement of T-staging was moderate (k = 0.41). There were 98 patients of N+ and 116 patients of N- at histopathology. Area under the curve of receiver operating characteristics to differentiate lymph node metastasis was 0.63. Sensitivity and specificity of size criteria of the largest lymph node (cut off value: > 6mm, > 7mm, and > 8mm) to predict pathologic N+ were 90% and 17%, 78% and 34%, and 68% and 51%, respectively. Conclusions: Re-staging using CT after neoadjuvant chemotherapy showed suboptimal accuracy and over-staged residual tumor. However, it predicted downstaging of gastric cancer with high accuracy.

e16562 Background: Aberrant expression of mucins can promote the epithelial-mesenchymal transition (EMT), which leads to enhanced tumorigenesis. Carcinogenesis-related pathways involving c-MET and beta-catenin involve mucins. This study characterized expressions of MET, MUC5AC, MUC5B, and MUC6 EMT signaling in human gastric cancer (GC) cell lines, and further characterized the differential susceptibility of these cell lines to tepotinib. Methods: We assessed the antitumor activity of tepotinib in GC cell lines. The effect of tepotinib on cell viability (IC50), apoptotic cell death, the EMT, and c-MET and beta-catenin signaling were evaluated by MTS assay, flow cytometry, western blotting, and qRT-PCR. Antitumor efficacy was assessed in MKN45 xenograft mice. Results: Tepotinib treatment showed dose-dependent growth inhibition of c-MET-amplified SNU620, MKN45, and KATO III cells with concomitant induction of apoptosis, but tepotinib treatment did not have an effect on c-MET-reduced MKN28 and AGS cells. Tepotinib treatment also significantly reduced expressions of phospho-c-MET, total c-MET, phospho-ERK, total ERK, beta-catenin, and c-Myc protein in SNU620 and MKN45 cells. In contrast, this drug was only slightly active against KATO III cells. Notably, tepotinib significantly reduced the expressions of EMT promotion genes such as MMP7, COX-2, WNT1, MUC5B, and c-Myc in c-MET-expressed GC cells, and increased expressions of EMT suppression genes such as MUC5AC, MUC6, GSK3beta, and ECAD. In a murine xenograft model, tumor volumes were significantly reduced in the tepotinib-treated group, when administered by daily oral gavage at a dose of 10mg/kg/day. Histologically, tepotinib induced more necrosis than in the control group. Conclusions: These data show the possibility that tepotinib may have therapeutic effects in c-MET-amplified GC, suggesting that clinical studies need to confirm the therapeutic effect.

Lessons Learned Irinotecan could not be proven noninferior to paclitaxel as a second-line treatment for patients with metastatic or recurrent gastric cancer. The failure to demonstrate noninferiority may have been a result of insufficient patient enrollment. Both agents were tolerable but showed different toxicity profiles. Background This phase III study compared the efficacy and safety of paclitaxel versus irinotecan in patients with metastatic or recurrent gastric cancer (MRGC) who had experienced disease progression following first-line chemotherapy. Methods Patients were randomized to receive either paclitaxel (70 mg/m2; days 1, 8, 15, every 4 weeks) or irinotecan (150 mg/m2 every other week). The primary endpoint was progression-free survival (PFS). Results This study was stopped early due to low accrual rate. A total of 112 patients were enrolled; 54 were allocated to paclitaxel and 58 to irinotecan. Median PFS for the paclitaxel and irinotecan groups was 3.5 and 2.1 months, respectively (hazard ratio [HR], 1.27; 95% confidence interval [CI], 0.86–1.88; p = .234). Noninferiority of irinotecan to paclitaxel was not proved because the upper boundary of the 95% CI (1.88) exceeded the predefined upper margin of noninferiority (1.32). Median overall survival (OS) was 8.6 months in the paclitaxel group and 7.0 months in the irinotecan group (HR, 1.39; 95% CI, 0.91–2.11; p = .126). Among toxicities greater than or equal to grade 3, neutropenia (11.5%) was the most common, followed by peripheral neuropathy (7.7%) in the paclitaxel group, and neutropenia (34.5%) followed by nausea, vomiting, and anemia (8.6%, respectively) in the irinotecan group. Conclusion Although paclitaxel showed numerically longer PFS and OS compared with irinotecan, this was statistically insignificant. Both irinotecan and paclitaxel are valid second-line treatment options in MRGC.

A phase II study was conducted to evaluate the efficacy and safety of gemcitabine and S-1 combination chemotherapy in patients with metastatic biliary tract cancer (BTC). Patients with pathologically confirmed, unresectable, recurrent, or metastatic adenocarcinoma that originated from the intrahepatic or extrahepatic biliary ducts or gallbladder were assessed for eligibility. The primary end point was the overall response rate (ORR). The treatment consisted of 1,000 mg/m2 intravenous gemcitabine administered over 30 min on days 1 and 8, and 80 mg/m2 oral S-1 on days 1–14 of each cycle. The treatment was repeated every 3 weeks. Thirty-eight patients were enrolled between November 2005 and 2010. All patients had metastatic disease, and the primary sites of cancer were as follows: gallbladder in 12 (31.6 %), intrahepatic and extrahepatic bile ducts in 23 (60.5 %), and the ampulla of Vater in 3 (7.9 %) patients. One patient achieved a complete response, and six experienced a partial response. The ORR was 20.6 % (95 % CI 8.5–36.7] in the per-protocol (PP) population, and 18.4 % (95 %CI 6.1–30.7) in the intention-to-treat (ITT) population; the median response duration was 10.8 months. Nineteen patients had stable disease, and the disease control rate was 76.5 % (95 %CI 60.6–87.6) in the PP population. The median progression-free survival was 4.4 months (95 %CI 1.8–6.9), and the median overall survival was 9.0 months (95 %CI 4.0–13.9) with a 1-year survival rate of 44.7 % (95 %CI 29.0–61.5) in the ITT population. Grade 3/4 hematologic toxicities, neutropenia, anemia, and thrombocytopenia were observed in 13 (37.1 %), 9 (25.7 %), 2 (5.7 %), and 2 (5.7 %) patients, respectively. One patient experienced a grade 3 febrile neutropenia without any documented infection. The grade 3/4 non-hematologic toxicities were hepatic toxicity (11.4 %), anorexia (2.9 %), and renal toxicity (2.9 %). Gemcitabine and S-1 combination chemotherapy showed acceptable efficacy and favorable toxicity profiles. Therefore, it might offer an alternative therapeutic strategy in patients with BTC.

Doublet chemotherapy of platinum and 5-fluorouracil is a standard first-line treatment for patients with unresectable gastric cancer. Although the addition of taxane or irinotecan to this regimen has yielded promising efficacy, its use has been limited due to severe toxicities. To overcome this limitation, we evaluated the efficacy and safety of the combination of irinotecan, oxaliplatin, and S-1 (OIS) for the treatment of advanced gastric cancer. Chemotherapy-naive patients with pathologically proven advanced gastric adenocarcinoma were assessed for eligibility. Irinotecan (135 mg/m2) and oxaliplatin (65 mg/m2) were administered intravenously on day 1, and S-1 (80 mg/m2/day) was administered orally on days 1–7 of every 2-week cycle. Forty-four patients (median age 57 years) were enrolled and all but one patient had a good performance status (ECOG 0 or 1). A total of 529 cycles were administered, with a median of 9.5 (range 1–31) cycles per patient. The overall response rate was 61.4% (95% confidence interval [CI] 46.6–74.3). The median progression-free survival and overall survival were 10.8 months (95% CI 7.6–14.0) and 15.4 months (95% CI 12.6–18.2), respectively. Major toxicities included grade 3/4 neutropenia (38.6%), febrile neutropenia (13.6%), abdominal pain (9.1%), and diarrhea (9.1%). These data suggest that the OIS regimen is effective and relatively well tolerated in patients with advanced gastric cancer. Given that all the patients treated, but one, had a good performance status, these results must be confirmed in a patient population more representative of regular clinical practice. ClinicalTrials.gov Identifier: NCT02527785.

Purpose Preoperative chemoradiation therapy (CRT) followed by total mesorectal excision (TME) in locally advanced rectal cancer is the standard of care. To date, the role of consolidation chemotherapy after CRT has rarely been addressed through randomized trials. This study aimed to evaluate the efficacy of CRT followed by consolidation chemotherapy compared with CRT alone. Methods and Materials This study enrolled patients with adenocarcinoma of the rectum and cT3 or cT4 disease with any N category and no metastasis. In arm A (control arm), we planned CRT (50.4 Gy in 28 fractions) with capecitabine followed by TME. In arm B, 2 cycles of capecitabine and oxaliplatin were administered 1 week after the completion of CRT before TME (capecitabine, 1700 mg/m2 per day from day 1 to 14, and oxaliplatin, 100 mg/m2 on day 1, every 3 weeks). The downstaging rate (the proportion of ypT0 to ypT2 and ypN0M0) was the primary endpoint, which was to be tested with a 1-sided type I error of 15% and with 85% power. Results From September 2014 to February 2016, 110 patients (56 in arm A and 54 in arm B) were randomized and 108 (55 in arm A and 53 in arm B) started CRT. TME was conducted per protocol in 96 patients (52 in arm A and 44 in arm B). In arms A and B, downstaging was achieved in 21.2% and 36.4% (P = .077), respectively, and the pathologic complete response rate was 5.8% and 13.6% (P = .167), respectively. Grade ≥3 adverse events occurred in 3.6% of patients in arm A and 9.4% of patients in arm B during the preoperative treatment phase and in 1.9% and 9.0%, respectively, during the postoperative recovery phase. Conclusions Consolidation chemotherapy with 2 cycles of capecitabine and oxaliplatin demonstrated a marginal improvement in the downstaging rate. However, a phase 3 trial of this strategy is discouraged because of the high dropout rate and safety issues.

Ramucirumab improves survival in gastric cancer patients. The efficacy and safety of ramucirumab outside of a clinical trial were evaluated using an expanded access program (EAP). Advanced gastric cancer patients treated with ramucirumab in combination with paclitaxel or with ramucirumab monotherapy in a Korean EAP were evaluated. Baseline characteristics were assessed for progression-free survival (PFS) and overall survival (OS), and adverse events were evaluated according to the treatment regimen. Of 265 patients, 228 received ramucirumab plus paclitaxel, and 37 received ramucirumab monotherapy. Grade 3 or 4 neutropenia was more common with ramucirumab plus paclitaxel than with ramucirumab monotherapy (46.7 vs. 8.1%). Gastrointestinal (GI) perforation developed in seven patients (3.1%) in the ramucirumab plus paclitaxel group. The overall response and disease control rates were 16.6 and 66.3% in the ramucirumab plus paclitaxel group, and 5.4 and 37.8% in the ramucirumab monotherapy group, respectively. PFS and OS were 3.8 and 8.6 months in the ramucirumab plus paclitaxel group, and 1.8 and 6.4 months in the ramucirumab monotherapy group, respectively. In multivariate analysis, alkaline phosphatase, albumin, and neutrophil-to-lymphocyte ratio (NLR) were the independent prognostic factors for PFS, while albumin, NLR, number of metastatic sites, and large amount of ascites were independent prognostic factors for OS. In the Korean EAP cohort, ramucirumab showed similar efficacy to the results of the previous trials for gastric cancer. However, the level of GI perforation was slightly increased in the ramucirumab plus paclitaxel group.

Purpose Bone marrow biopsy is a standard method for the evaluation of bone marrow infiltration by lymphoma; however, it is an invasive and painful procedure. Fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET-CT) is a noninvasive imaging technique with the potential to detect bone marrow involvement by lymphoma. Materials and Methods We retrospectively reviewed medical records of lymphoma patients. All patients were examined by FDG PET-CT and iliac crest bone marrow biopsy for initial staging work-up. Results The study population comprised 94 patients (median age, 60 years; 56 males) with Hodgkin’s lymphoma (n=8) or non-Hodgkin’s lymphoma (n=86). Maximum standardized uptake values on the iliac crest of patients with lymphoma infiltrated bone marrow were significantly higher than those of patients with intact bone marrow (2.2±1.2 g/mL vs. 1.3±0.4 g/mL; p=0.001). The calculated values for FDG PET-CT during evaluation of bone marrow involvement were as follows: sensitivity 50%, specificity 96%, positive predictive value 80%, negative predictive value 85%, and positive likelihood ratio (LR+) 11.7. The value of LR+ was 16.0 in patients with aggressive subtypes of non-Hodgkin’s lymphoma (NHL). Conclusion FDG PET-CT could not replace bone marrow biopsy due to the low sensitivity of FDG PET-CT for detection of bone marrow infiltration in lymphoma patients. Conversely, FDG PET-CT had high specificity and LR+; therefore, it could be a useful tool for image-guided biopsy for lymphoma staging, especially for aggressive subtypes of NHL. In addition, unilateral bone marrow biopsy could be substituted for bilateral bone marrow biopsy in lymphoma patients with increased FDG uptake on any iliac crest.

ABC-02 trial of gemcitabine plus cisplatin combination showed prolongation of overall survival in biliary tract cancer (BTC) patients. In this multicenter retrospective study, we evaluated the treatment outcome of gemcitabine combined with platinum (GP) compared to that of gemcitabine (G) alone in Korean BTC patients. One hundred and fifty-one patients with histologically confirmed biliary tract adenocarcinoma were enrolled at nine institutions between July 2003 and May 2011, including 100 treated with GP and 51 treated with G. With a median follow-up of 7.7 months (range 0.4–38.3 months), the median overall survival (OS) was 12.4 months [95 % confidence interval (CI) 9.4–15.6 months] of the G group, which was not significantly different for the median OS of 11.0 months (95 % CI 9.7–12.3 months) of the GP group (p = 0.599). The median progression-free survival (PFS) was 3.9 months (95 % CI 0.8–7.0 months) in the G group and 3.3 months (95 % CI 2.6–4.0 months) in the GP group (p = 0.504). Overall response rates (ORR) were 18.8 % in G group and 23.9 % in GP group (p = 0.485). There was no significant difference in ORR, PFS, or OS for patients between the G group and the GP group, which was different from the ABC-02 trial. Therefore, gemcitabine monotherapy and GP combination are both effective regimens for Korean BTC patients.

Although gastric cancer is quite common in Korea, the treatment outcome is relatively favorable compared to those in western countries. However, there are currently no Korean multidisciplinary guidelines for gastric cancer. Experts from related societies developed guidelines de novo to meet Korean circumstances and requirements, including 23 recommendation statements for diagnosis (n=9) and treatment (n=14) based on relevant key questions. The quality of the evidence was rated according to the GRADE evidence evaluation framework: the evidence levels were based on a systematic review of the literature, and the recommendation grades were classified as either strong or weak. The applicability of the guidelines was considered to meet patients' view and preferences in the context of Korea. The topics of the guidelines cover diagnostic modalities (endoscopy, endoscopic ultrasound, and radiologic diagnosis), treatment modalities (surgery, therapeutic endoscopy, chemotherapy, and radiotherapy), and pathologic evaluation. An external review of the guidelines was conducted during the finalization phase.

e13023 Background: Next generation sequencing (NGS) in hematological tumors is increasingly shaping clinical treatment decisions at the point of care. While the impact of NGS panels in solid tumors is largely therapeutic, targeted sequencing in hematological tumors can additionally provide diagnostic and prognostic insights. Additional data generated in hematological tumor sequencing makes manual interpretation and annotation of variants tedious and non-scalable. In this study we compared hematological tumor variant interpretation using an artificial intelligence decision-support system, Watsonä for Genomics (WfG), with expert guided manual curation. Methods: Patients with hematological tumors at Hallym University, College of Medicine between December 2017 and December 2018, were sequenced using the 54 gene Illumina TruSight Myeloid Panel. WfG interpreted and annotated all patients’ sequencing results, a subset of which were assessed manually to ascertain concordance. Results: 54 South Korean patients with hematological malignancies were analyzed (23 Acute Myeloid Leukemia, 12 myeloproliferative neoplasm, 5 myelodysplastic syndrome, 5 multiple myeloma and 9 others). Comparison of manual and WfG interpretation of 10 randomly selected cases yielded 90% (9/10) concordance and identification of 9 clinically actionable variants (33%) not found in manual interpretation. In total, WfG identified that 71% (38/54) of all cases had at least one clinically actionable therapeutic alteration (a variant targeted by a US FDA approved drug, off-label drug, or clinical trial). 33% (18/54) of cases had genes that were targeted by a US FDA approved therapy including JAK2, IDH1, IDH2, and FLT3. In cases without therapeutic alterations, WfG identified diagnostic or prognostic insights in an additional 20% (11/54) of patients. 9% (5/54) had no clinically actionable information. Conclusions: WfG variant interpretation correlated well with manually curated expert opinion and identified clinically actionable insights missed by manual interpretation. WfG has obviated the need for labor-intensive manual curation of clinical trials and therapy, enabling our center to exponentially scale our NGS operations.

e13025 Background: Next generation sequencing (NGS) studies on various cancer types have revealed clinical insights on the molecular etiology of tumors and defined new treatment paradigms. However, the genomic landscape of a tumor type may be predicated on race. Application of broad-brush findings from one population to another may lead to erroneous treatment decisions. While the majority of published NGS cancer studies focus on Caucasian populations, few studies evaluate the molecular profiles of a tumor type between different demographies. In this study, acute myeloid leukemia (AML) patients of East Asian descent were sequenced at a South Korean hospital, interpreted, and compared with the Caucasian population from The Cancer Genome Atlas (TCGA). Methods: 23 South Korean AML patients were sequenced in 2018 using the 54 gene Illumina TruSight Myeloid Panel at Hallym University, College of Medicine. Orthogonal testing for FLT3-internal tandem duplication (ITD) was done by Sanger sequencing. Watsonä for Genomics (WfG), an artificial intelligence decision-support system, was used for variant interpretation and annotation. Additionally, 181 AML patients of Caucasian descent from the TCGA dataset were analyzed for comparison. Results: WfG identified at least 1 clinically actionable therapeutic alteration in 70% (16/23) of all Asian cohort cases. FLT3-ITD or tyrosine kinase domain (TKD) mutations were reported in 27% (49/181) of cases in the TCGA cohort but only 9% (2/23) of the Asian cohort. DNMT3A mutations were detected in 25% (45/181) and 74% (17/23) of the TCGA and Asian cohorts, respectively. Other oncogenic mutations in AML including NRAS, IDH1, IDH2, CEBPA, TET2, and NPM1 were represented at comparable frequencies between the two populations. Conclusions: Tumor biomarkers that affect prognosis can be informative in the clinical setting. In our study, FLT3 and DNMT3A, predictors of poor prognosis in AML, demonstrated decreased and increased respective frequencies in South Koreans compared to Caucasians, suggesting that some mutational signatures that predict cancer outcome may vary by race.