Dose Of Gemcitabine Research Articles

Obinutuzumab Plus Gemcitabine, Dexamethasone and Cisplatin (O-GDP) As Salvage Chemotherapy Prior to Autologous Stem Cell Transplant in Aggressive B Cell Lymphoma

Background: CCTG LY.12 defined GDP (gemcitabine, dexamethasone and cisplatin) (GDP) as an effective outpatient salvage chemotherapy regimen in relapsed/refractory (R/R) patients with aggressive lymphomas who are candidates for autologous stem cell transplant (ASCT) (Crump et al. JCO 2014). Obinutuzumab (O) is an alternative anti-CD20 that may produce responses in rituximab-refractory lymphomas. Head-to-head, O did not improve efficacy compared to R when combined with CHOP as initial therapy (Vitolo JCO 2017). However, salvage therapy differs from initial therapy in that patients have been previously exposed to, and have relapsed after, prior R. We therefore performed a single centre, single arm clinical trial of O-GDP to assess safety and efficacy in R/R aggressive B cell lymphoma as a salvage regimen prior to consolidation with ASCT. Methods: Transplant eligible patients with DLBCL and transformed indolent lymphoma were treated with O-GDP for two cycles, followed by response assessment by CT. Non-progressers received a third cycle of O-GDP for stem cell mobilization and final response assessed by CT-PET prior to ASCT. O was given at 1000 mg weekly during the first cycle of GDP and then on day 1 of cycles 2 and 3. Responses were determined by Lugano criteria using investigator assessment. The primary outcome is ORR by CT imaging after 2 cycles. The pre-specified statistical analysis stated that the trial will be declared positive if the ORR is >60%, negative if the ORR is <40% and indeterminate if in-between. Secondary outcomes included complete metabolic response rate after 3 cycles of O-GDP and the rate of proceeding to ASCT. Exploratory outcomes included measurements of circulating tumor (ct) DNA during protocol therapy, and analysis of individual mutations. Double-hit score and cell of origin assessments were as previously described (Ennishi et al. JCO 2019). Outcomes: 30 patients were enrolled with a median age of 59.5 years (range 30 - 70). 20 patients had DLBCL, 9 had transformed indolent lymphoma (TRIL; all but one patient having transformed follicular lymphoma) and 1 patient had follicular lymphoma grade 3B. IPI at diagnosis was 0-1 (20% of patients), 2 (30%) or 3+ (50%). Dose delays of O during cycle 1 occurred in 10% of patients due to toxicity with delays in cycle 2 or 3 of O-GDP in 30% of patients. 87% of patients had a dose reduction of chemotherapy with 46% of day 8 gemcitabine doses being held or reduced. Grade 3-4 AEs were seen in 87% of patients (grade 3-4 neutropenia: 77% [febrile neutropenia: 13%]; grade 3 anemia: 13%; grade 3-4 thrombocytopenia: 43%). The ORR (CR + PR) by CT imaging after 2 cycles of study therapy was 60% (95% CI 41-77%). The best ORR (by Lugano criteria including PET/CT) after 3 cycles of study therapy was 70% (51-85%; CMR in 33%) of patients. Of all enrolled patients, 67% (47-83%) proceeded to ASCT. With a median follow up 1.3 years for all enrolled patients, the estimated 1 year OS was 76% (62-93%) and PFS was 59% (44-80%). The OS and PFS in transplanted patients at 1 year was 90% (77-100) and 70% (53-93%) respectively with a median follow-up of 1 year. In post hoc subset analysis, de novo DLBCL had a best ORR of 55% while TRIL/FL3B had an ORR of 100%. The presence of the double hit (DHIT) signature and cell of origin (COO) by gene expression was analyzed in 26/30 patients. Best ORR for DHIT positive was 3/4 patients (75%), DHIT negative was 11/16 (69%) and DHIT indeterminate was 5/6 (83%). Best ORR for ABC-type was 7/10 (70%), GCB-type was 9/13 (69%), unclassified was 1/1 (100%) and PMBL was 1/2 (50%). Conclusions: O-GDP is a feasible outpatient salvage regimen that enables ASCT in patients with R/R aggressive B cell lymphoma across histological and molecular subtypes. Higher rates of cytopenias with O-GDP contributed to treatment delays and dose reductions or holds. Further mutational analysis will be presented. The ORR of 60% met the study primary endpoint and the 1 year OS and PFS are encouraging. Disclosures Jain: Kite/Gilead: Consultancy. Prica:Celgene: Honoraria; Janssen: Honoraria. Kukreti:Amgen: Honoraria; Takeda: Honoraria; Celgene: Honoraria. Kridel:Gilead Sciences: Research Funding. Crump:Servier: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Kite/Gilead: Consultancy. Scott:Roche/Genentech: Research Funding; Celgene: Consultancy; Janssen: Consultancy, Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding. Kuruvilla:Abbvie: Consultancy; Seattle Genetics: Consultancy; Merck: Consultancy; Janssen: Honoraria; Karyopharm: Honoraria; Celgene: Honoraria; Gilead: Honoraria; Seattle Genetics: Honoraria; Roche: Honoraria; Roche: Consultancy; Karyopharm: Consultancy; Novartis: Honoraria; Gilead: Consultancy; Janssen: Research Funding; Roche: Research Funding; BMS: Consultancy; Merck: Honoraria; BMS: Honoraria; Astra Zeneca: Honoraria; Amgen: Honoraria. OffLabel Disclosure: Obinutuzumab is an anti-CD20 antibody being tested here in a prospective clinical trial for relapsed/refractory aggressive B cell lymphomas

Niveau, a Phase 3 Study for Pts with B- or T-Cell Aggressive Non-Hodgkin Lymphoma in First Relapse or Progression Not Eligible for High-Dose Chemotherapy (HDT), Testing Nivolumab in Combination with Gemcitabine, Oxaliplatin (GemOx), Plus Rituximab (R) in Case of B-Cell Lymphoma

Niveau, a Phase 3 Study for Pts with B- or T-Cell Aggressive Non-Hodgkin Lymphoma in First Relapse or Progression Not Eligible for High-Dose Chemotherapy (HDT), Testing Nivolumab in Combination with Gemcitabine, Oxaliplatin (GemOx), Plus Rituximab (R) in Case of B-Cell Lymphoma

Oncogenic ADAM28 induces gemcitabine resistance and predicts a poor prognosis in pancreatic cancer.

BACKGROUNDPancreatic cancer is a major cause of cancer-related death, with a 5-year overall survival rate being below 5%. The main causes of poor prognosis in pancreatic cancer include easy metastasis, high recurrence rate, and robust drug resistance. Gemcitabine is a first-line drug for patients with unresectable pancreatic cancer. However, due to drug resistance, the clinical effect is not satisfactory. ADAM28 is reported as a tumor promoter in some cancers, but its role in pancreatic cancer and gemcitabine chemoresistance in pancreatic cancer has not been elucidated.AIMTo identify if ADAM28 can act as an important target to reverse the gemcitabine drug resistance in pancreatic cancer.METHODSRNA-sequence analysis was applied to explore the potential targets involved in the gemcitabine of pancreatic cancer. SW1990 pancreatic cancer cells were treated with an increased dose of gemcitabine, and the mRNA levels of ADAM28 were evaluated by RT-PCR. The protein and mRNA levels of ADAM28 were confirmed in the gemcitabine resistant and parallel SW1990 cells. The ADAM28 expression was also assessed in TCGA and GEO databases, and the results were confirmed in the collected tumor and adjacent normal tissues. The overall survival (OS) rate and relapse-free survival (RFS) rate of pancreatic cancer patients with high ADAM28 level and low ADAM28 level in TCGA were evaluated with Kaplan-Meier Plotter. Furthermore, the OS rate was calculated in pancreatic cancer patients with high tumor mutation burden (TMB) and low TMB. CCK-8 assay was used to examine the effect of ADAM28 on the viability of SW1990 cells. The ADAM28 and its co-expressed genes were analyzed in the cBioPortal for cancer genomics and subjected to GSEA pathway analysis. The correlations of ADAM28 with GSTP1, ABCC1, GSTM4, and BCL2 were analyzed based on TCGA data on pancreatic cancer.RESULTSRNA-sequence analysis identified that ADAM28 was overexpressed in gemcitabine-resistant cells, and gemcitabine treatment could induce the expression of ADAM28. The mRNA and protein levels of ADAM28 were elevated in gemcitabine-resistant SW1990 cells compared with parallel cells. Also, the expression of ADAM28 was upregulated in pancreatic tumor tissues against normal pancreatic tissues. Notably, ADAM28 was highly expressed in the classical type than in the basal tumor type. Furthermore, the high expression of ADAM28 was associated with low OS and RFS rates. Interestingly, the high levels of ADAM28 was associated with a significantly lower OS rate in the high TMB patients, but not in the low TMB patients. Moreover, overexpression of ADAM28 could reduce the cell viability inhibition by gemcitabine, and knockdown of ADAM28 could enhance the proliferation inhibition by gemcitabine. The GSEA analysis showed that ADAM28 was related to the regulation of drug metabolism, and ADAM28 was significantly positively correlated with GSTP1, ABCC1, GSTM4, and BCL2.CONCLUSIONThis study demonstrates that ADAM28 is overexpressed in pancreatic cancer, and closely involved in the regulation of gemcitabine resistance. Overexpression of ADAM28 is a novel prognostic biomarker in pancreatic cancer.

Phase Ib trial of gemcitabine with yttrium-90 in patients with hepatic metastasis of pancreatobiliary origin.

Gemcitabine, a chemotherapy for hepatic metastasis with pancreatic cancer (PC) or intrahepatic cholangiocarcinoma (ICC) origin, may radiosensitize the targeted tumor cells for yttrium-90 radioembolization (90Y-RE). This clinical trial was designed to investigate the effects of a combination of 90Y-RE and gemcitabine in hepatic metastasis of PC or ICC origin. Fourteen patients who had histopathologic diagnosis of unresectable hepatic metastasis of PC or ICC origin were enrolled into the open-label phase Ib clinical trial. Induction dose of gemcitabine on day 1 was followed by 90Y-RE on day 2 with predetermined doses of gemcitabine to follow till week 12. Maximal tolerated dose (MTD) of gemcitabine in combination with 90Y-RE, associated toxicities and hepatic progression free survival (HPFS) were assessed. The tumor response rate was evaluated using both RECIST and PERCIST criteria. Eight patients met the study criteria; three with PC and five with ICC. The mean age of the patients was 69.4 years. Seven out of 8 patients tolerated predetermined gemcitabine regime (dose level 1 at 400 mg/m2 and dose level 2 at 600 mg/m2). All of the patients developed grade 1 toxicities. Three patients (37.5%) had grade 2 hepatobiliary toxicity and one patient (12.5%) had grade 3 hepatobiliary toxicity, who was hospitalized for a short-term. The median HPFS was 8.7 months for all patients. The objective response rate was 62%. A combination of 90Y-RE and gemcitabine at 600 mg/m2 is a safe and potential treatment option for hepatic metastasis of pancreaticobiliary origin.

Gemcitabine/Cisplatin therapy for an urothelial carcinoma patient undergoing hemodialysis: a case report

Abstract Background Gemcitabine/Cisplatin (GC) therapy is first-line chemotherapy for advanced urothelial carcinoma (UC). The Renal Impairment Clinical Practice Guidelines 2016 suggest that, Cisplatin (CDDP) may be administered by up to 50% of standard dose for patients with hemodialysis (HD) because of the renal toxicity. The evidence is, however, scanty to evaluate safety. We report a case of GC therapy for a UC patient undergoing HD. Patient A 80-years old male with bilateral papillary UC had a total renal ureteral resection and underwent HD. Two courses of adjuvant GC therapy were to be performed. The standard dose of Gemcitabine (GEM) and 50% of standard dose of CDDP were administered on the same day based on CDDP and GEM interview form and literature for HD patients. HD started 6 hours after GEM administration and 1 hour after CDDP administration. The volume of infusion was 600 mL; diuretics were not used. Side effects were evaluated according to Common Terminology Criteria for Adverse Events v4.0. Results In first course, Grade 4 side effects were observed: leukopenia, neutropenia and thrombocytopenia. They were treated by granulocyte-colony stimulating factor (G-CSF) administration and platelet transfusion. No febrile neutropenia was observed. Because the second course was administered without reducing the doses, G-CSF was prophylactically administered, and the Grade 4 side effects were reduced to Grade 3. No relapse was observed by now. Conclusion We could performed GC therapy safety for a patient with advanced UC undergoing HD by managing adverse event adequately.

The synergism of Clinacanthus nutans Lindau extracts with gemcitabine: downregulation of anti-apoptotic markers in squamous pancreatic ductal adenocarcinoma

BackgroundClinacanthus nutans extracts have been consumed by the cancer patients with the hope that the extracts can kill cancers more effectively than conventional chemotherapies. Our previous study reported its anti-inflammatory effects were caused by inhibiting Toll-like Receptor-4 (TLR-4) activation. However, we are unsure of its anticancer effect, and its interaction with existing chemotherapy.MethodsWe investigated the anti-proliferative efficacy of polar leaf extracts (LP), non-polar leaf extracts (LN), polar stem extract (SP) and non-polar stem extracts (SN) in human breast, colorectal, lung, endometrial, nasopharyngeal, and pancreatic cancer cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assay. The most potent extracts was tested along with gemcitabine using our established drug combination analysis. The effect of the combinatory treatment in apoptosis were quantified using enzyme-linked immunosorbent assay (ELISA), Annexin V assay, antibody array and immunoblotting. Statistical significance was analysed using one-way analysis of variance (ANOVA) and post hoc Dunnett’s test. A p-value of less than 0.05 (p < 0.05) was considered statistical significance.ResultsAll extracts tested were not able to induce potent anti-proliferative effects. However, it was found that pancreatic ductal adenocarcinoma, PDAC (AsPC1, BxPC3 and SW1990) were the cell lines most sensitive cell lines to SN extracts. This is the first report of C. nutans SN extracts acting in synergy with gemcitabine, the first line chemotherapy for pancreatic cancer, as compared to conventional monotherapy. In the presence of SN extracts, we can reduce the dose of gemcitabine 2.38–5.28 folds but still maintain the effects of gemcitabine in PDAC. SN extracts potentiated the killing of gemcitabine in PDAC by apoptosis. Bax was upregulated while bcl-2, cIAP-2, and XIAP levels were downregulated in SW1990 and BxPC3 cells treated with gemcitabine and SN extracts. The synergism was independent of TLR-4 expression in pancreatic cancer cells.ConclusionThese results provide strong evidence of C. nutans extracts being inefficacious as monotherapy for cancer. Hence, it should not be used as a total substitution for any chemotherapy agents. However, SN extracts may synergise with gemcitabine in the anti-tumor mechanism.

Combination Treatment of the Oral CHK1 Inhibitor, SRA737, and Low-Dose Gemcitabine Enhances the Effect of Programmed Death Ligand 1 Blockade by Modulating the Immune Microenvironment in SCLC

IntroductionDespite the enthusiasm surrounding cancer immunotherapy, most SCLC patients show very modest response to immune checkpoint inhibitor monotherapy treatment. Therefore, there is growing interest in combining immune checkpoint blockade with chemotherapy and other treatments to enhance immune checkpoint blockade efficacy. Based on favorable clinical trial results, chemotherapy and immunotherapy combinations have been recently approved by the U.S. Food and Drug Administration for frontline treatment for SCLC. Methods and ResultsHere, we show that combined treatment of SRA737, an oral CHK1 inhibitor, and anti–programmed death ligand 1 (PD-L1) leads to an antitumor response in multiple cancer models, including SCLC. We further show that combining low, non-cytotoxic doses of gemcitabine with SRA737 + anti–PD-L1/anti–PD-1 significantly increased antitumorigenic CD8+ cytotoxic T cells, dendritic cells, and M1 macrophage populations in an SCLC model. This regimen also led to a significant decrease in immunosuppressive M2 macrophage and myeloid-derived suppressor cell populations, as well as an increase in the expression of the type I interferon beta 1 gene, IFNβ, and chemokines, CCL5 and CXCL10. ConclusionsGiven that anti–PD-L1/anti–PD-1 drugs have recently been approved as monotherapy and in combination with chemotherapy for the treatment of SCLC, and that the SRA737 + low dose gemcitabine regimen is currently in clinical trials for SCLC and other malignancies, our preclinical data provide a strong rational for combining this regimen with inhibitors of the PD-L1/PD-1 pathway.

A phase 1b dose escalation study of Wnt pathway inhibitor vantictumab in combination with nab-paclitaxel and gemcitabine in patients with previously untreated metastatic pancreatic cancer

SummaryVantictumab is a fully human monoclonal antibody that inhibits Wnt pathway signaling through binding FZD1, 2, 5, 7, and 8 receptors. This phase Ib study evaluated vantictumab in combination with nab-paclitaxel and gemcitabine in patients with untreated metastatic pancreatic adenocarcinoma. Patients received vantictumab at escalating doses in combination with standard dosing of nab-paclitaxel and gemcitabine according to a 3 + 3 design. A total of 31 patients were treated in 5 dosing cohorts. Fragility fractures attributed to vantictumab occurred in 2 patients in Cohort 2 (7 mg/kg every 2 weeks), and this maximum administered dose (MAD) on study was considered unsafe. The dosing schedule was revised to every 4 weeks for Cohorts 3 through 5, with additional bone safety parameters added. Sequential dosing of vantictumab followed by nab-paclitaxel and gemcitabine was also explored. No fragility fractures attributed to vantictumab occurred in these cohorts; pathologic fracture not attributed to vantictumab was documented in 2 patients. The study was ultimately terminated due to concerns around bone-related safety, and thus the maximum tolerated dose (MTD) of the combination was not determined. The MAD of vantictumab according to the revised dosing schedule was 5 mg/kg (n = 16).

Tumor-specific delivery of gemcitabine with activatable liposomes

Gemcitabine delivery to pancreatic ductal adenocarcinoma is limited by poor pharmacokinetics, dense fibrosis and hypo-vascularization. Activatable liposomes, with drug release resulting from local heating, enhance serum stability and circulation, and the released drug retains the ability to diffuse within the tumor. A limitation of liposomal gemcitabine has been the low loading efficiency. To address this limitation, we used the superior solubilizing potential of copper (II) gluconate to form a complex with gemcitabine at copper:gemcitabine (1:4). Thermosensitive liposomes composed of DPPC:DSPC:DSPE-PEG2k (80:15:5, mole%) then reached 12 wt% loading, 4-fold greater than previously reported values. Cryo transmission electron microscopy confirmed the presence of a liquid crystalline gemcitabine‑copper mixture. The optimized gemcitabine liposomes released 60% and 80% of the gemcitabine within 1 and 5 min, respectively, at 42 °C. Liposomal encapsulation resulted in a circulation half-life of ~2 h in vivo (compared to reported circulation of 16 min for free gemcitabine in mice), and free drug was not detected within the plasma. The resulting gemcitabine liposomes were efficacious against both murine breast cancer and pancreatic cancer in vitro. Three repeated treatments of activatable gemcitabine liposomes plus ultrasound hyperthermia regressed or eliminated tumors in the neu deletion model of murine breast cancer with limited toxicity, enhancing survival when compared to treatment with gemcitabine alone. With 5% of the free gemcitabine dose (5 rather than 100 mg/kg), tumor growth was suppressed to the same degree as gemcitabine. Additionally, in a more aggressive tumor model of murine pancreatic cancer, liposomal gemcitabine combined with local hyperthermia induced cell death and regions of apoptosis and necrosis.

Abstract CT176: Phase III PANOVA study of tumor treating fields (150 kHz) in combination with nab-paclitaxel and gemcitabine for front-line treatment of locally-advanced pancreatic adenocarcinoma (LAPC)

Abstract Background: Tumor Treating Fields (TTFields) are a non-invasive, regional antimitotic treatment modality, which has been approved for the treatment of patients with glioblastoma by the FDA. TTFields predominantly act by disrupting the formation of the mitotic spindle during metaphase. TTFields were effective in multiple preclinical models of pancreatic cancer. The Phase II PANOVA study [NCT01971281] of TTFields in pancreatic cancer (metastatic and LAPC) combined with nab-paclitaxel and gemcitabine, demonstrated no TTFields-related serious adverse events; key TTFields-related AEs was manageable skin toxicity. TTFields plus gemcitabine and nab-paclitaxel showed median PFS was 12.7 months. The Phase III PANOVA-3 trial [NCT03377491] is designed to test the efficacy of adding TTFields to nab-paclitaxel and gemcitabine combination in LAPC. Methods: Patients (N = 556) with unresectable, LAPC (per NCCN guidelines) will be enrolled in this prospective, randomized trial. Patients should have an ECOG score of 0-2 and no prior progression or treatment. Patients will be stratified based on their performance status and geographical region, and will be randomized 1:1 to TTFields plus nab-paclitaxel and gemcitabine or to nab-paclitaxel and gemcitabine alone. Chemotherapy will be administered at standard dose of nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2 once weekly). TTFields (150kHz) will be delivered at least 18 hours/day until local disease progression per RECIST Criteria V1.1. Follow up will be performed q8w, including a CT scan of the chest and abdomen. Following local disease progression, patients will be followed monthly for survival. Overall survival will be the primary endpoint and progression-free survival, objective response rate, rate of resectability, quality of life and toxicity will all be secondary endpoints. Sample size was calculated using a log-rank test comparing time to event in patients treated with TTFields plus chemotherapy with control patients on chemotherapy alone. The PANOVA-3 study is designed to detect a hazard ratio 0.75 in overall survival. Type I error is set to 0.05 (two-sided) and power to 80%. Citation Format: Uri Weinberg, Ori Farber, Moshe Giladi, Zeev Bomzon, Eilon Kirson. Phase III PANOVA study of tumor treating fields (150 kHz) in combination with nab-paclitaxel and gemcitabine for front-line treatment of locally-advanced pancreatic adenocarcinoma (LAPC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT176.

Abstract 117: Pharmacological targeting of activated PSC decreases resistance to gemcitabine and increases survival in murine PDA

Abstract Background: Pancreatic ductal adenocarcinoma (PDA) is the most lethal form of cancer owing to its insensitivity to many chemotherapeutic drugs. Gemcitabine remains a cornerstone of PDA treatment despite suboptimal efficacy in clinics. One major mechanism by which PDA becomes resistant to gemcitabine is its conversion to inactive derivative, dFdU by upregulation of the enzyme, cytidine deaminase (Cda) in cancer cells. Activated pancreatic stellate cells (PSC) are the major source of IGF1 in the tumor microenvironment, which may be responsible for an increase in Cda expression in cancer cells. We previously reported a rationally designed protein, ProAgio that targets integrin αVβ3 at a novel site. Here we demonstrate that ProAgio specifically induces apoptosis of integrin αVβ3-expressing activated PSC and therefore circumvents gemcitabine resistance in murine PDA models. Objective: To test whether targeting activated PSC restores chemotherapeutic sensitivity in previously unresponsive PDA tumors in a murine model. Methods: To study the effect of ProAgio and gemcitabine combination in PDA, we used two murine PDA models: a) KP orthotopic mouse model where KPC cells were orthotopically injected into the pancreas and, b) LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) mouse model. Mice were treated with 20 doses of ProAgio (10mg/kg; i.p.) and 10 doses of gemcitabine twice weekly (50mg/kg; i.p.). IGF1 and Cda levels were analyzed by ELISA and immunohistochemistry. The intratumoral levels of the gemcitabine prodrug 2′,2′-difluorodeoxcytidine (dFdC) and the inactivated and activated metabolites (2′,2′-difluorodeoxyuridine (dFdU) and gemcitabine triphosphate (dFdCTP) respectively were determined by LCMS. Results: Our data in murine PDA models clearly demonstrate that pharmacological targeting of activated PSC by ProAgio can stabilize PDA, and when combined with gemcitabine significantly increased the survival benefit by 3-fold (p&amp;lt;0.001). Pharmacological targeting of activated PSC by ProAgio consequently decreases IGF1R signaling in cancer cells. As a result, there is a decrease in Cda expression leading to an increase in active metabolite, dfdCTP in the tumor, which contributes to the enhanced efficacy of gemcitabine. In conclusion, our findings for the first time demonstrate the mechanistic approach to target activated PSC, resulting in decreased Cda expression and enhanced gemcitabine delivery, thereby restoring chemotherapeutic sensitivity in murine PDA models. Citation Format: Ravi Chakra Turaga, Malvika Sharma, Falguni Mishra, Zhi-Ren Liu. Pharmacological targeting of activated PSC decreases resistance to gemcitabine and increases survival in murine PDA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 117.

Abstract LB-148: Combination treatment of the CHK1 inhibitor, SRA737, and low dose gemcitabine demonstrates profound synergy with anti-PDL1 inducing durable tumor regressions and modulating the immune microenvironment in small cell lung cancer

Abstract Background: Small cell lung cancer (SCLC), the most aggressive form of lung cancer, shows poor response rates to immunotherapy targeting the programmed cell death protein 1 pathway (PD-(L)1). Our group previously discovered that SCLC exhibits high expression of checkpoint kinase 1 (CHK1) and that the CHK1 inhibitor SRA737 activates the innate immune STING pathway, demonstrating robust anti-tumor activity and synergy in combination with anti-PD-L1 in an SCLC model. As SRA737 is being tested in SCLC patients in combination with low dose gemcitabine (LDG), we evaluated the efficacy and immune correlates (including macrophages associated with resistance to immune checkpoint blockade) of the SRA737+LDG regimen in combination with anti-PD-L1 in an SCLC model. Results: Trp53, Rb1 and p130 (RPP) triple knockout SCLC cells were implanted into the flank of B6129F1 immunocompetent mice. After the mice developed tumors, they were treated with single agents or various drug combinations. Anti-PD-L1 and LDG demonstrated minimal effect on tumor growth as single agents and only a modest effect as a combination. Moderate to strong anti-tumor activity was however observed with SRA737 monotherapy which directly correlated with dosing intensity. The most profound and synergistic anti-tumor activity was observed when anti-PD-L1 was combined with the SRA737+LDG regimen, with all animals showing durable regressions. Analysis of tumor infiltrating immune cells at the end of this treatment regimen showed a dramatic induction of cytotoxic T-cells and a reduction of exhausted and regulatory T cells. Similarly, pro-inflammatory M1 type macrophages and dendritic cells were increased while immunosuppressive M2 type macrophages and MDSC cells were dramatically decreased. As monotherapy, the more dose intensive SRA737 schedule resulted in similar effects on lymphocytes when combined with anti-PD-L1. These effects are consistent with our previous data showing that SRA737 treatment leads to an induction of STING and type I interferon signaling in tumors, which is associated with the establishment of an anti-tumor immune microenvironment. Discussion: Our findings suggest that the combination of anti-PD-L1 with the SRA737+LDG regimen may represent the optimal implementation of these agents, leading to a dramatic anti-tumor activity accompanied by the establishment of a strong anti-tumor immune microenvironment. Given that anti-PD-(L)1 drugs are approved but show limited efficacy in SCLC, our preclinical data provide a strong rationale for combining these agents with the SRA737+LDG regimen to enhance clinical response rates. Citation Format: Triparna Sen, Carminia M. Della Corte, Snezana Milutinovic, Lixia Diao, Robert J. Cardnell, Ryan J. Hansen, Bryan Strouse, Michael P. Hedrick, Christian Hassig, Jing Wang, Lauren A. Byers. Combination treatment of the CHK1 inhibitor, SRA737, and low dose gemcitabine demonstrates profound synergy with anti-PDL1 inducing durable tumor regressions and modulating the immune microenvironment in small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-148.

Abstract 1421: Low dose gemcitabine increases the sensitivity of human Vgamma9Vdelta2T cell mediated cytotoxicity through NKG2D-NKG2D ligands axis in bladder cancer cells

Abstract INTRODUCTION AND OBJECTIVES: In clinical trials, Zoledronic acid (ZOL) pretreatment in cancer cells is widely used to improve the efficacy of human γδT cell immunotherapy. We herein provide new strategies for the enhancement of γδT cell function by anticancer pretreatment in urinary bladder cancer (UBC) cells. The aim of this study was whether pretreatment of cancer cells with standard anticancer agents would increase the cytotoxicity of γδT cells. METHODS: The surface expression of NKG2D, TCRVγ9, TCRVδ2 and the intracellular levels of perforin and Granzyme B in γδT cells were examined. In in vitro assays, UBC cell lines T24, TCCSUP, and UMUC3 were used. Flow cytometric analysis of Carboxyfluorescein diacetate succinimidyl ester (CFSE) /propidium iodide (PI) staining was used in in vitro cytotoxicity assays. Imaging of cancer cells lysed by human γδT cell was captured by laser microscopy. UBC cells were treated with various standard anticancer agents at sub-lethal concentrations, including cisplatin (CDDP), gemcitabine (GEM), methotrexate (MTX), vinblastine (VBL), adriamycin (ADR), and mitomycin C (MMC). The expressions of MICA/B, ULBP1, and ULBP2/5/6 in UBC cells were investigated. In in vivo experiments, the efficacy of intravesical administration of ex vivo-expanded γδT cells was examined in an orthotopic xenograft model using In Vivo Imaging System (IVIS). RESULTS: Ex vivo-expanded γδT cell expressed NKG2D receptor on the cell surface and both TCRVγ9, TCRVδ2 positive lineage were well expanded. Activation of ex vivo-expanded γδT cell was confirmed by intracellular staining of granules, containing perforin and Granzyme B. We examined the synergistic effects of anticancer agents and γδT cells in vitro. We found that these anticancer agents upregulated the expressions of MICA/B and ULBP family in UBC cells, which γδT cells use to recognize cancer cells and resulted in the increased cytotoxicity of γδT cells. The cytotoxicity was abrogated by induction of siRNA against MICA/B. These findings were also confirmed in MICA/B or NKG2D blocking experiments. We also found that intravesical administration of γδT cells showed potent cytotoxicity using an orthotopic xenograft. Finally, we revealed that low dose gemcitabine pretreatment synergistically increased the cytotoxicity of γδT cells in vivo. CONCLUSIONS: These results indicated that γδT cell adoptive immunotherapy in combination with standard anticancer agents is an effective strategy and may be a promising approach to the treatment of UBC. Citation Format: Teruki Shimizu, Mako Tomogane, Yusuke Sano, Daiki Shimizu, Masatsugu Miyashita, Atsuko Fujihara, Fumiya Hongo, Osamu Ukimura, Eishi Ashihara. Low dose gemcitabine increases the sensitivity of human Vgamma9Vdelta2T cell mediated cytotoxicity through NKG2D-NKG2D ligands axis in bladder cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1421.

Secretion of fibronectin by human pancreatic stellate cells promotes chemoresistance to gemcitabine in pancreatic cancer cells

BackgroundGemcitabine remains a cornerstone in chemotherapy of pancreatic ductal adenocarcinoma (PDAC) despite suboptimal clinical effects that are partly due to the development of chemoresistance. Pancreatic stellate cells (PSCs) of the tumor stroma are known to interact with pancreatic cancer cells (PCCs) and influence the progression of PDAC through a complex network of signaling molecules that involve extracellular matrix (ECM) proteins. To understand tumor-stroma interactions regulating chemosensitivity, the role of PSC-secreted fibronectin (FN) in the development of gemcitabine resistance in PDAC was examined.MethodsPSC cultures obtained from ten different human PDAC tumors were co-cultured with PCC lines (AsPC-1, BxPC-3, Capan-2, HPAF-II, MIA PaCa-2, PANC-1 and SW-1990) either directly, or indirectly via incubation with PSC-conditioned medium (PSC-CM). Gemcitabine dose response cytotoxicity was determined using MTT based cell viability assays. Protein expression was assessed by western blotting and immunofluorescence. PSC-CM secretome analysis was performed by proteomics-based LC-MS/MS, and FN content in PSC-CM was determined with ELISA. Radiolabeled gemcitabine was used to determine the capacity of PCCs to uptake the drug.ResultsIn both direct and indirect co-culture, PSCs induced varying degrees of resistance to the cytotoxic effects of gemcitabine among all cancer cell lines examined. A variable degree of increased phosphorylation of ERK1/2 was observed across all PCC lines upon incubation with PSC-CM, while activation of AKT was not detected. Secretome analysis of PSC-CM identified 796 different proteins, including several ECM-related proteins such as FN and collagens. Soluble FN content in PSC-CM was detected in the range 175–350 ng/ml. Neither FN nor PSC-CM showed any effect on PCC uptake capacity of gemcitabine. PCCs grown on FN-coated surface displayed higher resistance to gemcitabine compared to cells grown on non-coated surface. Furthermore, a FN inhibitor, synthetic Arg-Gly-Asp-Ser (RGDS) peptide significantly inhibited PSC-CM-induced chemoresistance in PCCs via downregulation of ERK1/2 phosphorylation.ConclusionsThe findings of this study suggest that FN secreted by PSCs in the ECM plays a key role in the development of resistance to gemcitabine via activation of ERK1/2. FN-blocking agents added to gemcitabine-based chemotherapy might counteract chemoresistance in PDAC and provide better clinical outcomes.

Prolonged low-dose infusion for gemcitabine: a systematic review.

BackgroundThe present standard dose of gemcitabine (Gem), a pyrimidine antimetabolite, is 1,000–1,250 mg/m2, and the infusion time is 30 min. However, pharmacological studies have demonstrated that Gem with prolonged infusion could attain a better accumulation rate of Gem triphosphate (active metabolites of Gem), indicating that Gem with prolonged infusion is superior to 30-min infusion. Thus, this systematic review aims to provide some references for Gem administered as a prolonged infusion.MethodsWe searched electronic databases, including PubMed, EMBASE, Cochrane Library, and CNKI, for trials. Keywords were “Gem,” “prolonged infusion,” and “low-dose.” In addition, we used the Cochrane Handbook V5.1.0 and methodological index for non-randomized studies to evaluate the quality of randomized controlled trials (RCTs) and non-RCTs, respectively. Furthermore, Cochrane Collaboration guidelines and the PRISMA statement were adopted.ResultsWe systematically reviewed 19 studies (5 RCTs and 14 non-RCTs). All studies assessed the efficacy and safety of Gem administered as a prolonged low-dose infusion (P-LDI) and reported that Gem administered as P-LDI was effective and well tolerated.ConclusionGem administered as P-LDI is effective, safe, and economical, especially suited for patients with poor performance status or without good economic condition.

PF752 AUTOLOGOUS STEM CELL TRANSPLANT CONDITIONING WITH CHIDAMIDE, CLADRIBINE, GEMCITABINE AND BUSULFAN AS CONSOLIDATION MAY OVERCOME POOR PROGNOSIS OF PATIENTS WITH DOUBLE EXPRESSER LYMPHOMA

Background:Double‐protein‐expression lymphomas (DEL) is a unique sub‐group of diffuse large B‐cell lymphoma (DLBCL) with co‐expression of MYC and BCL‐2 on immunohistochemistry. Compared with classic DLBCL, DEL has a lower response to standard induction chemoimmunotherapy with rituximab added to cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP) and poorer prognosis. Autologous stem cell transplant (ASCT) is a potentially curative treatment of high‐risk of relapsed/refractory lymphomas. However, the role of ASCT in patients with DEL is controversy. Our pre‐clinic and clinic studies showed the combination of chidamide, cladribine, gemcitabine and busulfan (ChiCGB) worked synergistically against lymphomas.Aims:So, in this study, we used ASCT conditioning with ChiCGB as consolidation in patients with DEL in first or second complete remission.Methods:This study was a phase 2 trial done at the West China Hospital of Sichuan University from May. 2016 to Dec. 2018. Eligible patients were aged 16–65 years and had received R‐CHOP or chidamide‐R‐CHOP as first‐line or any second‐line therapies. They achieve first or second complete remission (CR) before transplant. The DEL was diagnosed as MYC expression ≥ 40% and BCL‐2 ≥ 50% on immunohistochemistry. Additional eligibility criteria were an Eastern Cooperative Oncology Group (ECOG) performance status of 0–2, adequate major organs function, no active hepatitis bacteria, fungal or virus infection. Patients provided written informed consent to participate in the trial. Patients with DLBCL without MYC and BCL‐2 over‐expression were assigned to the control group (non‐DEL).Patients received ChiCGB conditioning regimen consisting of oral chidamide 30 mg on days −7, −4, 0, +3, intravenous cladribine at a dose of 6 mg/m2 from days −6 to −2, intravenous gemcitabine 4 hours after cladribine at a dose of 2500 mg/m2 on days −6 and −2, and intravenous busulfan at a fixed dose of 3.2 mg/kg from days −6 to −2. Dexamethasone was prophylactically given for adverse effect of high dose gemcitabine from the day −6 to −2. Peripheral‐blood stem‐cells were infused on day 0.Results:A total of 44 patients with DLBCL were enrolled, with 22 DEL and 22 non‐DEL. The median age was 46 (range, 23 to 61) and 34.5 (range, 16 to 61) years in DEL and non‐DEL groups. There were 8 (36.3%) and 12 (54.5%) patients in second CR in DEL and non‐DEL group respectively. In DEL group, 5 patients receive chidamide‐R‐CHOP as first‐line therapy. Stem cells source was peripheral blood. Median infused CD34+cells count was 2.2 × 106/Kg (range, 1.0 to 11.6 × 106/Kg). Neutrophils and platelets were engrafted on a median day +10 (+8 to +14) and day +12 (range, days +8 to +38), respectively. The median follow‐up was 17.8 (range, 4.1 to 34.9) and 20 (range, 3 to 46.3) months in DEL and non‐DEL group. The 2‐year progression free survival of patients with DEL or non‐DEL was 94.4% and 84.2% (P = 0.3731), while the 2‐year overall survival of tow groups was 94.1% and 100% (P = 0.2904) (Figure‐1).Summary/Conclusion:Our study showed ChiCGB efficiently prevented relapse of DEL. Compared with the survival of patients with non‐DEL, ChiCGB with ASCT may overcome poor prognosis of patients with diffuse large B‐cell lymphoma with co‐expression of MYC and BCL‐2.image

Comparison of salvage therapies for relapsed or refractory diffuse large B-cell lymphoma (DLBCL): Network meta-analysis.

e19037 Background: Salvage chemotherapy followed by autologous stem cell transplantation(ASCT) is the standard second-line treatment for relapsed or refractory diffuse large b-cell lymphoma(DLBCL). Rituximab plus ifosfamide, carboplatin, and etoposide(R-ICE) and rituximab plus dexamethasone, high dose cytarabine, cisplatin(R-DHAP) are the two widely used regimens worldwide but quest for optimal regimen continues. Our objective is to compare currently available salvage therapies based on complete response and adverse events. Methods: Pubmed, EMBASE and Clinicaltrials.gov were queried for salvage therapies in relapsed or refractory DLBCL. Only randomized clinical trials including phase 2 and 3 trials involving salvage therapies for relapsed or refractory DLBCL were selected. Data was extracted based on meta-analysis guidelines by two independent reviewers. Network meta-analyses of treatment effects and adverse outcomes were calculated with a frequentist approach. Results: Overall, 5 studies(1480 patients) were included. The salvage therapies investigated were rituximab plus ifosfamide, carboplatin, and etoposide(R-ICE), rituximab plus dexamethasone, high dose cytarabine, cisplatin(R-DHAP), rituximab plus gemcitabine, dexamethasone, cisplatin(R-GDP), ofatumumab plus dexamethasone, cytarabine, and cisplatin(O-DHAP), ifosfamide plus ofatumunab, carboplatin, and etoposide(O-ICE), dacetuzumab plus rituximab, ifosfamide, carboplatin and etoposide(DR-ICE). Of the 6 regimens in the network, treatment with R-DHAP (OR:0.36,95%CI:0.24-0.54), R-GDP(OR:0.37,95%CI: 0.21-0.65), O-ICE(OR:0.16,95%CI: 0.05-0.53), O-DHAP(OR:0.30,95%CI:0.17-0.52), DR-ICE(OR:0.77,95%CI:0.40-1.49) were not superior against network placebo(R-ICE) in achieving complete response. Higher odds of occurring severe adverse events was observed in R-DHAP(OR:2.02,95%CI: 1.35-3.01) and O-DHAP(OR:2.15,95%CI: 1.24-3.72) salvage regimens when compared to R-ICE. Conclusions: R-DHAP, R-GDP, O-ICE and O-DHAP were found to have no difference in treatment effect in achieving complete response in comparison to R-ICE. R-DHAP and O-DHAP are associated with higher number of severe adverse events in comparison with R-ICE. Outcomes mentioned above should be interpreted in the context of drugs and other factors involved in the disease.

SOPHIA primary analysis: A phase 3 (P3) study of margetuximab (M) + chemotherapy (C) versus trastuzumab (T) + C in patients (pts) with HER2+ metastatic (met) breast cancer (MBC) after prior anti-HER2 therapies (Tx).

1000 Background: Pretreated HER2+ MBC lacks a defined standard of care, although T is commonly used. M has similar HER2 binding and antiproliferative effects as T. By contrast, M’s Fc region is engineered to increase affinity for both alleles of the activating Fc receptor (FcR), CD16A, and decrease affinity for the inhibitory FcR, CD32B. The low affinity CD16A-158F allele (~85% of population) has been associated with diminished clinical response to T. In a Phase 1 trial, M demonstrated acceptable safety, anti-tumor activity, and evidence of HER2-specific antibody and T-cell responses. Methods: SOPHIA (NCT02492711), a randomized, open-label P3 trial, enrolled pts with HER2+ MBC after pertuzumab and 1–3 lines of prior Tx for MBC. Pts were randomized 1:1 to M (15 mg/kg IV q3w + C) or T (6 [8 for loading dose] mg/kg IV q3w + C), stratified by met sites (≤2, &gt; 2), lines of Tx for met disease (≤2, &gt; 2), and C choice (standard dose capecitabine, eribulin, gemcitabine, or vinorelbine). Primary endpoints are central blinded PFS and OS, assessed sequentially using the stratified log-rank test. Objective response rate (ORR) was a secondary endpoint. 257 PFS events were required to provide 90% power to show PFS superiority at 2-sided α = 0.05. Results: Intent-to-treat analysis (536 pts: M 266; T 270) occurred after 265 PFS events. M prolonged PFS over T (median 5.8 vs 4.9 mo, hazard ratio [HR], 0.76; 95% CI, 0.59–0.98; P= 0.033). Treatment effects were more pronounced in pts with CD16A genotypes containing a 158F allele (median PFS 6.9 vs 5.1 mo, HR, 0.68; 95% CI, 0.52–0.90; P= 0.005). In 524 pts with baseline measurable disease (M 262; T 262), ORR was higher with M (22%; 95% CI, 17.3-27.7%) vs T (16%; 95% CI 11.8-21.0%). Safety profiles were comparable in 529 pts who received study therapy. Grade ≥3 AEs and serious AEs occurred in 138 (52%) and 39 (15%) vs 128 (48%) and 46 (17%) pts on M vs T, respectively. PFS data cutoff: 10/10/18. Conclusions: In combination with chemotherapy in pretreated HER2+ MBC, M improves PFS over T with comparable safety. CD16A genotyping suggests a differential benefit in patients with a 158F allele. OS data are maturing. Clinical trial information: NCT02492711.

A phase I/II first-in-human trial of oral SRA737 (a Chk1 inhibitor) given in combination with low-dose gemcitabine in subjects with advanced cancer.

3095 Background: SRA737 is a potent, highly selective and orally-bioavailable inhibitor of checkpoint kinase 1 (Chk1). SRA737-02 was designed to investigate the safety, tolerability and preliminary activity of SRA737 in a novel combination with sub-therapeutic doses of gemcitabine (low dose gemcitabine; LDG) utilized to potentiate SRA737’s activity by induction of replication stress in subjects with advanced solid tumors. Methods: Phase 1 dose escalation investigated cohorts of 3 to 6 subjects receiving escalating doses of SRA737 for 2 days after LDG administration on days 1, 8, 15 of 28-day cycles. Phase 2 expansion cohorts explored the hypothesis that LDG strongly synergizes with SRA737 in subjects with genetically-defined tumors hypothesized to be sensitive to Chk1 inhibition: urothelial, high grade serous ovarian, small cell lung, soft tissue sarcoma, and cervical or anogenital cancers. Results: A total of 55 subjects received SRA737 in 13 dose escalation cohorts at doses of 40 to 600 mg SRA737 combined with LDG doses of 50 to 300 mg/m2. No protocol-defined dose limiting toxicities (DLTs) have been observed. The pharmacokinetic profile of SRA737 revealed an AUC0-24 and Cmax of 3550 ng∙h/mL and 548 ng/mL at 150 mg SRA737. At this dose, the Cmin (52 ng/mL) exceeded that determined in preclinical models to be effective. Enrollment into expansion cohorts was initiated at 500 mg SRA737 plus 100 mg/m2 LDG with intra-patient dose escalation permitted to 250 mg/m2 LDG. Approximately 80 subjects were planned and 82 have been treated. Median treatment duration was 51 days (range 1 to 358). The most common treatment-emergent adverse events were nausea (53%), vomiting (45%), fatigue (40%), diarrhea (38%), and anemia (28%); the majority were of mild to moderate severity. Proof-of-concept clinical activity has been seen in tumor types such as anal, cervical, and rectal. Conclusions: The combination of LDG and SRA737 has been well tolerated. This first-in-human clinical study provides proof-of-concept that sub-therapeutic LDG effectively potentiates SRA737. This novel replication stress-targeted therapy warrants further evaluation in genetically pre-defined solid tumors. Clinical trial information: NCT02797977.

A pilot safety study of gemcitabine and cisplatin (GC) with atezolizumab (A) as first-line therapy in patients (pts) with metastatic urothelial cancer (mUC).

4559 Background: GC has a high overall response rate (ORR) but a high relapse rate in pts with untreated mUC. Inhibition of programmed death-ligand 1 (PD-L1) with A can lead to long-term survival, but single-agent ORR is modest. We report the outcomes of GC+A in a cohort pts with mUC. Methods: This study was designed to assess the safety of GC + A in 10 pts with untreated mUC prior to testing GC + A in a neoadjuvant study in pts with muscle-invasive disease. The primary endpoint was safety as assessed by a predefined dose limiting toxicity (DLT) rate during the first cycle in the first 6 pts. Total accrual goal was 10 pts to collect preliminary data on ORR and progression-free survival (PFS). RECIST 1.1 assessments were performed every 9 wks. Pts received 6 cycles of GC + A induction and then A maintenance every 3 wks. Results: No DLTs occurred during the first cycle in the first 6 pts. Grades 3-4 neutropenia and anemia occurred in 6/10 and 7/10 pts, respectively. Three pts required gemcitabine dose reductions for hematologic toxicity and 2 pts had febrile neutropenia. One pt discontinued cisplatin after 2 cycles for grade 3 hearing impairment but completed induction with gemcitabine and A. Only 1 pt discontinued study therapy due to treatment-related adverse events (AEs), including A-related grade 4 encephalopathy and grade 3 polyneuropathy. Three of 10 pts had visceral (liver or bone) metastases. Of the 10 pts, 1 pt is completing induction but meets initial criteria for partial response (PR), 8 pts had confirmed PR, and 1 pt had progressive disease (PD). Of 9 pts with confirmatory scans, the median PFS was 10.6 months (95% CI 6.7, N/A). Of 8 pts with confirmed PR, 5 eventually had PD, 1 has just completed induction, 1 remains without PD at 25 months, and 1 had consolidation surgery with a pathologic complete response and remains disease-free at 21 months. Conclusions: This 10 pt study met its primary safety endpoint. The neoadjuvant study is ongoing (NCT02989584). Although there were a substantial number of grade 3-4 toxicities, therapy was discontinued due to treatment-related AEs in only 1 pt. Immune correlative studies are ongoing. Clinical trial information: NCT02989584.