Low-dose Irinotecan Research Articles

SARC037: Phase II results of trabectedin given as a 1-hour (h) infusion in combination with low dose irinotecan in patients (pts) with relapsed/refractory Ewing sarcoma (ES).

SARC037: Phase II results of trabectedin given as a 1-hour (h) infusion in combination with low dose irinotecan in patients (pts) with relapsed/refractory Ewing sarcoma (ES).

Targeting Methionine Addiction Combined With Low-dose Irinotecan Arrested Colon Cancer in Contrast to High-dose Irinotecan Alone, Which Was Ineffective, in a Nude-mouse Model.

Colorectal cancer (CRC) is the third-leading cause of death in the world. Although the prognosis has improved due to improvement of chemotherapy, metastatic CRC is still a recalcitrant disease, with a 5-year survival of only 13%. Irinotecan (IRN) is used as first-line chemotherapy for patients with unresectable CRC. However, there are severe side effects, such as neutropenia and diarrhea, which are dose-limiting. We have previously shown that methionine restriction (MR), effected by recombinant methioninase (rMETase), lowered the effective dose of IRN of colon-cancer cells in vitro. The aim of the present study was to evaluate the efficacy of the combination of low-dose IRN and MR on colon-cancer in nude mice. HCT-116 colon-cancer cells were cultured and subcutaneously injected into the flank of nude mice. After the tumor size reached approximately 100 mm3, 18 mice were randomized into three groups; Group 1: untreated control on a normal diet; Group 2: high-dose IRN on a normal diet (2 mg/kg, i.p.); Group 3: low-dose IRN (1 mg/kg i.p.) on MR effected by a methionine-depleted diet. There was no significant difference between the control mice and the mice treated with high-dose IRN, without MR. However, low-dose IRN combined with MR was significantly more effective than the control and arrested colon-cancer growth (p=0.03). Body weight loss was reversible in the mice treated by low-dose IRN combined with MR. The combination of low-dose IRN and MR acted synergistically in arresting HCT-116 colon-cancer grown in nude mice. The present study indicates the MR has the potential to reduce the effective dose of IRN in the clinic.

SARC037: Results of phase I study of trabectedin given as a 1-hour (h) infusion in combination with low dose irinotecan in relapsed/refractory Ewing sarcoma (ES).

11519 Background: Recurrent ES carries a poor prognosis, and systemic therapies have limited efficacy. Preclinical models suggested that trabectedin (T) could achieve serum concentrations high enough to suppress the dominant oncogene of ES (i.e. EWS::FLI1 transcription factor), and that this effect is sustained by subsequent administration of low dose irinotecan (I). We conducted a phase I study of T+I in patients (pts) with ES. Methods: This multicenter dose escalation study employed a standard 3+3 design. T was given as a 1-h infusion on day (D)1 with low dose I intravenously on D2 and 4 of a 21D cycle. Dose limiting toxicities (DLTs) were evaluated in cycle one. Eligibility required confirmed EWS::FLI1 fusion transcript, age ≥10 years, ECOG performance status ≤2, adequate organ function and willing to have a research biopsy if safely accessible. Primary objectives were to determine the recommended dose (RD) and safety of T+I. Secondary objectives comprised efficacy of T+I and avidity of ES for 3'-Deoxy-3'-18F Fluorothymidine (18F-FLT) PET. Results: 20 pts enrolled from 1/2021-12/2022 across 5 sites, 5F/15M, median age 18 years (range 10-59). Pts had received a median of 4 (range 2-9) prior therapy lines including irinotecan in 60% of pts. Grade (G) 3/4 treatment-emergent adverse events (TEAEs) occurring in ≥10% of pts were: elevated ALT/AST, elevated creatinine phosphokinase, febrile neutropenia, anemia, lymphopenia, neutropenia, and thrombocytopenia. There were 2 G5 respiratory TEAEs. 18F-FLT PET scans were obtained in 5 pts. ES tumors were 18F-FLT PET avid. Dose level (DL)2 was the RD. At DL 2 and above, there were 4 PRs, 6 SD in 14 evaluable pts (Table). Conclusions: T+I can be safely administered to heavily pretreated pts with ES, demonstrating activity at the RD with 3 PRs (n=5 evaluable). The 18F-FLT PET may be useful to understand patterns of disease progression in ES. Correlative studies will be critical to understanding the mechanism of drug activity. Given the clinical benefit seen with T+I at RD, a phase II portion in pts with ES ≥6 years old is actively accruing. Clinical trial information: NCT04067115 . [Table: see text]

Abstract CT088: Phase I/II study of the PARP inhibitor olaparib in combination with irinotecan in children with advanced malignancies: arm D of the AcSé-ESMART trial

Abstract Background: AcSé-ESMART is a proof-of-concept, phase I/II, platform trial, designed to explore targeted agents in a molecularly enriched relapsed/refractory pediatric population. Arm D was evaluating the PARP inhibitor (PARPi) olaparib (ola) in combination with irinotecan (iri). In contrast to other PARPi/chemotherapy combination studies, we opted for a prolonged course of PARPi and low dose irinotecan as sensitizer. The Phase I part previously established the recommended Phase II dose (RP2D) (Gatz ASCO 2019). This is the report of the Phase II part of the trial assessing the activity in two separate expansion cohorts: cohort 1: homologous recombination repair defect (HRD) and cohort 2: Ewing sarcoma (ES). Methods: Ola was administered orally twice daily at 90 mg/m2 on Days 1 to 10 and iri intravenously at 20 mg/m2 on Days 4 to 8 of a 21-day cycle. Activity assessment followed a Minimax Simon 2-stage design. Each cohort was to progress to the second stage (additional 9 patients) if 2 or more confirmed responses were observed in the first 16 patients. Patients treated in the Phase I part at the RP2D were counting towards the respective expansion cohorts. Results: Seventy patients (median age: 14 years, range 5-23) were included in the whole study, 67 received treatment; 27 patients were treated in the dose escalation part, including 10 at the RP2D (8 in cohort 1 and 2 in cohort 2). Both cohorts passed the 1st stage and a total of 24 and 26 patients were recruited to cohort 1 and 2, respectively. Main diagnoses in cohort 1 were sarcoma (n=10), brain tumor (n=9), neuroblastoma (n=4). In cohort 1, 15 of 24 patients were considered enriched based on molecular alteration at relapse (ATM n=6; BRCA1 n=2; DNA signature 3 n=3; FANCD2, CHEK2, FANCA, ATRX all n=1); all patients in cohort 2 had presence of a ES fusion (ESWR1::FLI1 n=22; EWSR1::ERG n=4). Median number of treatment cycles were 2, range 1;51 in cohort 1 and 1;32+ in cohort 2. In cohort 1, 3 patients had a partial response (PR) (pinealoblastoma, neuroblastoma, choroid plexus carcinoma; treated with 12, 51, 25 cycles), 1 patient an unconfirmed PR (rhabdomyosarcoma, 6 cycles) and 7 patients stable disease (SD) (2 prolonged with 6 and 8 cycles). In cohort 2, 1 patient had a complete response (10 cycles) and 1 a PR (32+ cycles), 7 patients had SD (3 prolonged with 6, 10, 16 cycles). Molecular enrichment did not predict response. Retrospective correlative analysis of the molecular profiling data and tumor tissue expression analysis are ongoing to identify predictive biomarkers for PARPi combination trials and data will be presented. Conclusions: Encouraging clinical benefit was observed with the protracted ola-iri schedule in a subset of patients. Current molecular hypothesis is insufficient for patient selection and better biomarkers are needed. Citation Format: Susanne A. Gatz, Pablo Berlanga, Baptiste Archambaud, Yassine Bouchoucha, Nicolas André, Nadege Corradini, Windy Rondof, Jonathan Rubino, Souad Nebchi, Antonin Marchais, Estelle Thebaud, Alba Rubio San Simón, Natasha K. van Eijkelenburg, Lynley V. Marshall, Anne-Sophie Defachelles, Adela Canyete, Stephane Ducassou, Guy Makin, Michela Casanova, Emilie De Carli, Arnaud Petit, Gwenael Le Teuff, Xavier Paoletti, Peter G. Mortimer, Gilles Vassal, Birgit Geoerger. Phase I/II study of the PARP inhibitor olaparib in combination with irinotecan in children with advanced malignancies: arm D of the AcSé-ESMART trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT088.

FOLFOXIRI vs FOLFIRINOX as first-line chemotherapy in patients with advanced pancreatic cancer: A population-based cohort study.

BACKGROUNDFOLFIRINOX regimen is the first-line reference chemotherapy (L1) in advanced pancreatic ductal adenocarcinoma (aPDAC). FOLFOXIRI, a schedule with a lower dose of irinotecan and no bolus 5-fluorouracil, has demonstrated efficacy and feasibility in colorectal cancer.AIMTo investigate the potential clinical value of FOLFOXIRI in patients with aPDAC in routine clinical practice.METHODSAnalyses were derived from all consecutive aPDAC patients treated in L1 between January 2011 and December 2017 in two French institutions, with either FOLFOXIRI (n = 165) or FOLFIRINOX (n = 124) regimens. FOLFOXIRI consisted of irinotecan (165 mg/m2), oxaliplatin (85 mg/m2), leucovorin (200 mg/m2) and 5-fluorouracil (3200 mg/m2 as a 48-h continuous infusion) every 2 wk. Ninety-six pairs of patients were selected through propensity score matching, and clinical outcomes of the two treatment regimens were compared.RESULTSMedian overall survival was 11.1 mo in the FOLFOXIRI and 11.6 mo in the FOLFIRINOX cohorts, respectively. After propensity score matching, survival rates remained similar between the two regimens in terms of overall survival (hazard ratio = 1.22; P = 0.219) and progression-free survival (hazard ratio = 1.27; P = 0.120). The objective response rate was 37.1% in the FOLFOXIRI group vs 47.8% in the FOLFIRINOX group (P = 0.187). Grade 3/4 toxicities occurred in 28.7% of patients in the FOLFOXIRI cohort vs 19.5% in the FOLFIRINOX cohort (P = 0.079). FOLFOXIRI was associated with a higher incidence of grade 3/4 digestive adverse events. Hematopoietic growth factors were used after each chemotherapy cycle and the low hematological toxicity rates were below 5% with both regimens.CONCLUSIONFOLFOXIRI is feasible in L1 in patients with aPDAC but does not confer any therapeutic benefit as compared with FOLFIRINOX. The low hematological toxicity rates strengthened the relevance of primary prophylaxis with hematopoietic growth factors.

Ultrasound-triggered therapeutic microbubbles enhance the efficacy of cytotoxic drugs by increasing circulation and tumor drug accumulation and limiting bioavailability and toxicity in normal tissues.

Most cancer patients receive chemotherapy at some stage of their treatment which makes improving the efficacy of cytotoxic drugs an ongoing and important goal. Despite large numbers of potent anti-cancer agents being developed, a major obstacle to clinical translation remains the inability to deliver therapeutic doses to a tumor without causing intolerable side effects. To address this problem, there has been intense interest in nanoformulations and targeted delivery to improve cancer outcomes. The aim of this work was to demonstrate how vascular endothelial growth factor receptor 2 (VEGFR2)-targeted, ultrasound-triggered delivery with therapeutic microbubbles (thMBs) could improve the therapeutic range of cytotoxic drugs.Methods: Using a microfluidic microbubble production platform, we generated thMBs comprising VEGFR2-targeted microbubbles with attached liposomal payloads for localised ultrasound-triggered delivery of irinotecan and SN38 in mouse models of colorectal cancer. Intravenous injection into tumor-bearing mice was used to examine targeting efficiency and tumor pharmacodynamics. High-frequency ultrasound and bioluminescent imaging were used to visualise microbubbles in real-time. Tandem mass spectrometry (LC-MS/MS) was used to quantitate intratumoral drug delivery and tissue biodistribution. Finally, 89Zr PET radiotracing was used to compare biodistribution and tumor accumulation of ultrasound-triggered SN38 thMBs with VEGFR2-targeted SN38 liposomes alone.Results: ThMBs specifically bound VEGFR2 in vitro and significantly improved tumor responses to low dose irinotecan and SN38 in human colorectal cancer xenografts. An ultrasound trigger was essential to achieve the selective effects of thMBs as without it, thMBs failed to extend intratumoral drug delivery or demonstrate enhanced tumor responses. Sensitive LC-MS/MS quantification of drugs and their metabolites demonstrated that thMBs extended drug exposure in tumors but limited exposure in healthy tissues, not exposed to ultrasound, by persistent encapsulation of drug prior to elimination. 89Zr PET radiotracing showed that the percentage injected dose in tumors achieved with thMBs was twice that of VEGFR2-targeted SN38 liposomes alone.Conclusions: thMBs provide a generic platform for the targeted, ultrasound-triggered delivery of cytotoxic drugs by enhancing tumor responses to low dose drug delivery via combined effects on circulation, tumor drug accumulation and exposure and altered metabolism in normal tissues.

Synergistic Anti-Tumor Effect of mTOR Inhibitors with Irinotecan on Colon Cancer Cells.

Advanced colorectal cancer has a poor prognosis because of metastasis formation and resistance to combined therapies. Downstream of PI3K/Akt and Ras/MAPK pathways, the mTOR kinase plays a decisive role in treatment failure. We previously established that irinotecan has antiangiogenic properties and it is known that new mammalian target of rapamycin (mTOR) catalytic AZD inhibitors, unlike rapamycin, target both mTORC1 and mTORC2. Thus, we hypothesized that the complete inhibition of the PI3K/AKT/mTOR/HIF-1α axis with mTOR catalytic inhibitors and low doses of irinotecan may have antitumor effects. We showed that the AZD8055 and AZD2014 inhibitors were much more potent than rapamycin to reduce cell viability of four colon cell lines. On the other hand, whereas AZD2014 alone inhibits migration by 40%, the drug combination led to 70% inhibition. Similarly, neither irinotecan nor AZD2014 significantly reduced cell invasion, whereas a combination of the two inhibits invasion by 70%. In vivo, irinotecan and AZD2014 combination drastically reduced ectopic patient-derived colon tumor growth and this combination was more potent than Folfox or Folfiri. Finally, the combination totally inhibited liver and lung metastases developed from orthotopic implantation of SW480 cells. Thus, the use of mTOR catalytic inhibitors, in association with other chemotherapeutic agents like irinotecan at low doses, is potentially a hope for colon cancer treatment.

716P - FOLFOXIRI versus FOLFIRINOX in first-line chemotherapy in patients with advanced pancreatic cancer: A propensity score analysis

BackgroundAdvanced pancreatic ductal adenocarcinoma (aPDAC) remains a challenging, non-curable disease. FOLFIRINOX regimen is the standard in first-line chemotherapy (L1) in this setting. FOLFOXIRI, a similar schedule with a lower dose of irinotecan and no bolus 5-fluorouracil, has demonstrated efficacy and good tolerance in metastatic colorectal cancer. We aimed to compare clinical outcomes of this two regimens in patients with aPDAC in routine clinical practice. MethodsAnalyses were derived from all consecutive aPDAC patients treated in L1, between 2011 and 2017 in two French institutions, with FOLFOXIRI (n=165) or standard (n=124) regimens. FOLFOXIRI consisted of irinotecan (165mg/m2), oxaliplatin (85mg/m2), leucovorin (200mg/m2) and 5-fluorouracil (3200mg/m2 as a 48-hour continuous infusion) every two weeks. One hundred pairs of patients were selected through propensity score matching (PSM) analysis and clinical outcomes of the two treatments were compared. ResultsAfter a median follow up of 44.1 months, median overall survival (OS) was 11.1 months (95% confidence interval [CI], 9.8 to 13.1) in the FOLFOXIRI group and 11.6 months (95% CI, 10.8 to 15.5) in the FOLFIRINOX group. Median progression free survival (PFS) was 5.8 months (95% CI, 3.9 to 6.9) in the FOLFOXIRI group and 6.7 months (95% CI, 6.0 to 7.7) in the FOLFIRINOX group. After PSM, the survival of patients remained similar between the two regimens in OS (hazard ratio [HR], 0.79; 95% CI, 0.58 to 1.08; P=0.137) and PFS (HR, 0.80; 95% CI, 0.60 to 1.08; P=0.139). The objective response rate was 33.3% in the FOLFOXIRI group versus 47.2% in the FOLFIRINOX group, while disease-control rates were 62.8% and 75.3%, respectively (P=0.129). The grade 3 or 4 toxicities were occurring in 29.0% of patients in FOLFOXIRI group versus 21.3% in FOLFIRINOX group (P=0.216). FOLFOXIRI was associated with a higher incidence of grade 3 or 4 digestive adverse events compared to FOLFIRINOX group (11.0% versus 5.0%, respectively) but was similar to the safety profile of FOLFIRINOX previously reported in the PRODIGE 4/ACCORD 11 trial. ConclusionsFOLFOXIRI is feasible in L1 in patients with aPDAC but does not confer any therapeutic benefit as compared with FOLFIRINOX regimen. Legal entity responsible for the studyBesançon University Hospital. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Functional mismatch repair and inactive p53 drive sensitization of colorectal cancer cells to irinotecan via the IAP antagonist BV6

A common strategy to overcome acquired chemotherapy resistance is the combination of a specific anticancer drug (e.g., topoisomerase I inhibitor irinotecan) together with a putative sensitizer. The purpose of this study was to analyze the cytostatic/cytotoxic response of colorectal carcinoma (CRC) cells to irinotecan, depending on the mismatch repair (MMR) and p53 status and to examine the impact of BV6, a bivalent antagonist of inhibitors of apoptosis c-IAP1/c-IAP2, alone or combined with irinotecan. Therefore, several MSH2- or MSH6-deficient cell lines were complemented for MMR deficiency, or MSH6 was knocked out/down in MMR-proficient cells. Upon irinotecan, MMR-deficient/p53-mutated lines repaired DNA double-strand breaks by homologous recombination less efficiently than MMR-proficient/p53-mutated lines and underwent elevated caspase-9-dependent apoptosis. Opposite, BV6-mediated sensitization was achieved only in MMR-proficient/p53-mutated cells. In those cells, c-IAP1 and c-IAP2 were effectively degraded by BV6, caspase-8 was fully activated, and both canonical and non-canonical NF-κB signaling were triggered. The results were confirmed ex vivo in tumor organoids from CRC patients. Therefore, the particular MMR+/p53mt signature, often found in non-metastasizing (stage II) CRC might be used as a prognostic factor for an adjuvant therapy using low-dose irinotecan combined with a bivalent IAP antagonist.

Trabectedin Inhibits EWS-FLI1 and Evicts SWI/SNF from Chromatin in a Schedule-dependent Manner

The successful clinical translation of compounds that target specific oncogenic transcription factors will require an understanding of the mechanism of target suppression to optimize the dose and schedule of administration. We have previously shown trabectedin reverses the gene signature of the EWS-FLI1 transcription factor. In this report, we establish the mechanism of suppression and use it to justify the reevaluation of this drug in the clinic in patients with Ewing sarcoma.Experimental Design: We demonstrate a novel epigenetic mechanism of trabectedin using biochemical fractionation and chromatin immunoprecipitation sequencing. We link the effect to drug schedule and EWS-FLI1 downstream target expression using confocal microscopy, qPCR, Western blot analysis, and cell viability assays. Finally, we quantitate target suppression within the three-dimensional architecture of the tumor in vivo using 18F-FLT imaging. Trabectedin evicts the SWI/SNF chromatin-remodeling complex from chromatin and redistributes EWS-FLI1 in the nucleus leading to a marked increase in H3K27me3 and H3K9me3 at EWS-FLI1 target genes. These effects only occur at high concentrations of trabectedin leading to suppression of EWS-FLI1 target genes and a loss of cell viability. In vivo, low-dose irinotecan is required to improve the magnitude, penetrance, and duration of target suppression in the three-dimensional architecture of the tumor leading to differentiation of the Ewing sarcoma xenograft into benign mesenchymal tissue. These data provide the justification to evaluate trabectedin in the clinic on a short infusion schedule in combination with low-dose irinotecan with 18F-FLT PET imaging in patients with Ewing sarcoma.

Modified-FOLFIRINOX combined with deep regional hyperthermia in pancreatic cancer: a retrospective study in Chinese patients

Background: FOLFIRINOX chemotherapy displays significant survival improvements in patients with pancreatic cancer. However, toxicities have hampered enthusiasm for the use of FOLFIRINOX in full dose. In order to increase the tolerability, many researchers focused on the modification of FOLFIRINOX. On the other hand, hyperthermia (HT) has been considered as an effective ancillary treatment for cancer therapy. Up to now, there is no report evaluating combining deep regional hyperthermia (DRHT) with modified-FOLFIRINOX for pancreatic cancer patients.Methods: In this study, we conducted a retrospective review of pancreatic cancer patients treated with the combination of new form modified-FOLFIRINOX and DRHT (BSD2000). Patients underwent chemotherapy that included low-dose irinotecan (70–130 mg/m2), oxaliplatin (65–70 mg/m2) on day 1 and 5-FU (2400 mg/m2 as a 46 h continuous infusion, no bolus) or capecitabine (CAP) (1000 mg/m2 twice daily on days 1–10) or tegafur, gimeracil and oteracil potassium (TS-1) (80–120 mg/d twice daily on days 1–10), 2-week schedule. Generally, DRHT treatment was performed weekly, 45 min for each time during chemotherapy.Results: The patients receiving mFOLFIRINOX as the first line chemotherapy combining with DRHT, obtained an improvement in OS and PFS, 17 months (95% CI 1.97–32.03 months) and 4 months (95% CI 0–8.29 months) respectively. Overall, this combination regimen was safe; 17.6% patients suffered from grade 3/4 toxicities.Conclusions: In conclusion, we conducted a retrospective study combining mFOLFIRINOX and DRHT, which was well tolerated. The efficacy in the treatment of pancreatic cancer was encouraging, but further studies would be required to prove its merit, compared with conventional treatment.

Abstract 5477: Targeting nicotinamide phosphoribosyltransferase (NAMPT) with OT-82 in Ewing sarcoma

Abstract EWS is an aggressive malignancy affecting adolescents and young adults, for which novel therapies are critically needed. Recent insights have revealed that NAMPT is a potential therapeutic target, mediating the rate limiting step of the NAD salvage pathway which converts nicotinamide (NAM) to nicotinamide mononucleotide (NMN). This pathway is preferentially utilized in tumor cells where it is essential for maintaining cellular bioenergetics and provides the necessary substrate for NAD-dependent proteins. OT-82 (OncoTartis) is a novel NAMPT inhibitor expected to enter early phase clinical trials in the near future. The purpose of this study was to evaluate the efficacy and mechanism of action of OT-82 as a single agent and in rational combinations in EWS. Proliferation of EWS cells lines was assessed after treatment with OT-82 as a single agent and in combinations with PARP inhibitors and DNA damaging agents using IncuCyte live cell analysis and MTS assays. Targeted activity of OT-82 was evaluated via NAD/NADH-Glo assays and rescue experiments with metabolic intermediates. Protein expression of targets was assessed with Western blot. For in vivo studies, SCID mice underwent orthotopic injection of EWS cells from established cell lines and PDX cells. When tumors reached a desired size, mice were randomized and treated with vehicle, OT-82, irinotecan, niraparib or combinations of OT-82 plus niraparib or irinotecan. Tumors were measured semiweekly with calipers and harvested at midpoints and at study endpoint for biology studies. EWS cell lines were sensitive to OT-82 in a dose-dependent manner, with IC50 values in the low nanomolar range for all cell lines tested, consistent with the known activity of NAMPT inhibitors in EWS cell lines. While NAMPT expression in EWS cell lines was high, the level of expression did not correlate with sensitivity to OT-82. OT-82 activity was on-target, demonstrated by dose-dependent reduction in NAD/NADH levels in EWS cells after treatment. This effect could be rescued through the addition of NMN in the majority of cell lines tested, supporting the proposed mechanism of OT-82 as a NAMPT inhibitor. When combined with either niraparib or SN-38, anti-proliferative activity was synergistic in vitro. In vivo, treatment with OT-82 resulted in tumor regression or growth inhibition in multiple xenograft models of EWS treated at doses between 25 and 50 mg/kg three days per week. When combined with low dose niraparib (50 mg/kg five days per week), tumor growth was suppressed, and survival time was significantly increased as compared to either single agent. When OT-82 was combined with low-dose irinotecan (2-5 mg/kg two days per week), the combination exhibited enhanced efficacy in multiple models. Biology studies of tumor tissue are ongoing and will be reported. OT-82 may be a novel targeted approach for the treatment of EWS and the addition of niraparib or irinotecan may enhance its efficacy. Citation Format: Anna E. Gibson, Arnulfo Mendoza, Lioubov Korotchkina, Olga Chernova, Christine M. Heske. Targeting nicotinamide phosphoribosyltransferase (NAMPT) with OT-82 in Ewing sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5477.

UGT1A1*6 and UGT1A1*28 polymorphisms are correlated with irinotecan-induced toxicity: A meta-analysis.

Previous articles explored the role of UGT1A1 polymorphism on predicting irinotecan-induced toxicity, but the conclusions were still inconsistent and not comprehensive. We performed this meta-analysis to investigate the association between UGT1A1 polymorphism and irinotecan-induced toxicity. PubMed and Web of Science were searched for articles before July 2017. Inclusion and exclusion criteria were set to select eligible articles, and corresponding data were extracted from those articles. Subgroup analyses based on different cancer categories, doses and races were carried out to achieve comprehensive results. Statistical analyses were conducted using STATA 11.0. A total of 38 studies with 6742 cases were included after reading full text. Both UGT1A1*6 and UGT1A1*28 polymorphism are significantly associated with severe irinotecan-induced toxicity. Both Asian and Caucasian cancer patients with UGT1A1*28 variant had an increased risk. Compared with heterozygous variant, patients with homozygous variant suffered from a higher risk of toxicity. The effect of UGT1A1*28 polymorphism on diarrhea was less than on neutropenia. Subgroup analysis exhibited that for UGT1A1*6 polymorphism, patients treated with low-dose irinotecan were at a notable risk of toxicity. Moreover, the association between UGT1A1*6 polymorphism and irinotecan-induced toxicity was found in patients suffering from respiratory system cancers. Both UGT1A1*6 and UGT1A1*28 polymorphisms can be considered as predictors of irinotecan-induced toxicity, with effect varying by race, cancer type and irinotecan dose.

Effects of quercetin combined with anticancer drugs on metastasis-associated factors of gastric cancer cells: in vitro and in vivo studies

Chemotherapy is essential to most patients with gastric cancer and the anticancer drug, irinotecan (CPT-11), and its metabolite, SN-38, an inhibitor of DNA topoisomerase I, are first-line chemotherapies for gastric cancer. Quercetin, a flavonoid that is widely found in various vegetables and fruits, has the ability to potentiate the efficacy of anticancer drugs. The purpose of this study was to investigate the therapeutic effect of quercetin combined with irinotecan/SN-38 in the AGS human gastric cancer cell line in vitro and in vivo. The in vitro study evaluated the efficacy of high-dose SN-38 and quercetin combined with low-dose SN-38 on cell viability, apoptosis, and β-catenin expression. Results showed that cell viability and the percentage of apoptosis in combined treatments with quercetin and SN-38 were comparable to treatment with high-dose SN-38 alone. AGS cells treated with a high dose of SN-38 exhibited up-regulation of β-catenin protein expression, whereas quercetin-treated cells (either quercetin alone or combined with low-dose SN-38) exhibited lower protein levels of β-catenin. In the AGS xenograft mouse model, gene expression of cyclooxygenase-2 and epithelial-mesenchymal transition-related markers, such as Twist1 and ITGβ6, were lower in combined treatments with quercetin and low-dose irinotecan than high-dose irinotecan alone. Furthermore, the concentration of angiogenesis-associated factors (vascular endothelial growth factor (VEGF)-A and VEGF-receptor 2) and percentage of Tie2-expressing monocytes was significantly down-regulated in combined treatments with quercetin and irinotecan. These results suggest that quercetin may enhance the efficacy of irinotecan/SN-38 in the human AGS cell line.

UGT1A1*6 polymorphisms are correlated with irinotecan-induced neutropenia: a systematic review and meta-analysis.

Irinotecan (IRI) chemotherapy toxicities can be severe, and may result in treatment delay, morbidity and in some rare cases death. Neutropenia is a life-threatening side effect of irinotecan, and UDP glucuronosyltransferases (UGTs) gene polymorphisms could predict the side effects in cancer patients and then reduce IRI-induced toxicity by preventative treatment or a decrease in dose. Both UGT1A1*6 and *28 were reliably demonstrated to be risk factors for IRI-induced neutropenia, with tests for both polymorphisms potentially being particularly useful in Asian cancer patients. However, some researchers reported that UGT1A1*6 could predict IRI-induced toxicities in Asian populations, controversial conclusions still remained. Thus, the association between UGT1A1*6 polymorphisms and IRI-induced severe toxicity in cancer patients is still needed to be explored. Therefore, this study aims to investigate the association between UGT1A1*6 polymorphisms and IRI-related severe neutropenia in cancer patients on a large scale. A total of 12 studies that included 746 wild genotype (G/G) cases and 394 variant genotype (G/A and A/A) cases were included on the basis of inclusion criteria. Then we assessed the methodologies quality; odds ratio (OR), risk difference (RD) and 95% confidence intervals (95% CI) were used to assess the strength of association. Overall, an increased risk of severe neutropenia in cancer patients with UGT1A1*6 polymorphisms was found. Patients with recessive models (GA+AA vs. GG) of UGT1A1*6 showed an increased risk (OR 2.03, 95% CI 1.54-2.68; RD=0.11, P<0.001). Specifically, the heterozygous variant of UGT1A1*6 showed an increased risk (OR 1.83, 95% CI 1.36-2.46; RD=0.09, P<0.001), and homozygous mutation showed also high risk (OR 2.95, 95% CI 1.83-4.75; RD=0.18, P<0.001) for severe neutropenia. Subgroup meta-analysis revealed that for patients harboring both heterozygous and homozygous variants, cancer types, low dose of IRI and the duration of treatment also presented comparably increased risk in suffering severe neutropenia. As for country, in China and Japan, there was a statistically increased severe neutropenia with variant genotype of UGT1A1*6 (China: GA+AA vs. GG, OR 1.83, 95% CI 1.28-2.59; RD=0.08, P=0.001; Japan: GA+AA vs. GG, OR 2.39, 95% CI 1.45-3.92; RD=0.15, P=0.001). In conclusion, in this meta-analysis, the UGT1A1*6 polymorphisms were associated with an increased risk of IRI-induced neutropenia in cancer patients, and increased incidences of severe neutropenia could be correlated with diverse regions, cancer type, low dose of IRI and the duration of treatment.

Suppression of lupus nephritis and skin lesions in MRL/lpr mice by administration of the topoisomerase I inhibitor irinotecan.

BackgroundSince the precise mechanism for the pathogenesis of systemic lupus erythematosus (SLE) is unknown, no targeted therapies in addition to immunosuppression are available so far. We recently demonstrated that administration of the topoisomerase I (topo I) inhibitor irinotecan at extremely low concentrations reversed established lupus nephritis in NZB/NZW mice. While profound immunosuppression was absent, we proposed changes in DNA relaxation and anti-double-stranded (ds)DNA antibody binding as the underlying mechanism. To exclude that these effects were restricted to NZB/NZW mice, irinotecan was used in a genetically different strain of lupus-prone mice.MethodsMRL/lpr mice were treated with high- and low-dose irinotecan beginning at 8 weeks of age. Treatment was repeated every fourth week. In vitro, DNA was relaxed by recombinant topo I, and altered anti-dsDNA antibody binding was measured by enzyme-linked immunosorbent assay.ResultsAdministration of both high- and low-dose irinotecan prevented proteinuria and prolonged survival in MRL/lpr mice. Moreover, both concentrations of irinotecan significantly improved histopathology of the skin at 18 weeks of age. While only high-dose irinotecan diminished the numbers of plasmablasts and double-negative T cells, no changes in IgG-secreting cells or anti-dsDNA IgG were observed. In vitro, relaxation of DNA by topo I increased the binding of anti-dsDNA IgG but not the binding of anti-dsDNA IgM derived from the plasma of MRL/lpr mice.ConclusionThe beneficial effects of topo I inhibition in a second, genetically different strain of lupus-prone mice strongly implicate irinotecan as a new therapeutic option for human SLE.

Irinotecan-induced toxicity pharmacogenetics: an umbrella review of systematic reviews and meta-analyses.

Irinotecan chemotherapy toxicities can be severe, and may result in treatment delay, morbidity and in some rare cases death. This systematic review of systematic reviews synthesises all meta-analyses on biomarkers for irinotecan toxicity across all genetic models for Asians, Caucasians, low dose, medium/high dose and regimens with and without fluorouracil. False-positive findings are a problem in pharmacogenetics, increasing the importance of systematic reviews. Four systematic reviews that investigated the effect of the polymorphisms UGT1A1*6 and/or*28 on neutropenia or diarrhoea toxicity were included. Both UGT1A1*6 and *28 were reliably demonstrated to be risk factors for irinotecan-induced neutropenia, with tests for both polymorphisms potentially being particularly useful in Asian cancer patients. UGT1A1*6 and *28 were also related to diarrhoea toxicity; however, at low doses of irinotecan there was evidence that UGT1A1*28 was not. In synthesising the best available evidence, this umbrella systematic review provides a novel reference for clinicians applying personalised medicine and identifies important research gaps.

Phase II trial of panitumumab with irinotecan as salvage therapy for patients with advanced or recurrent colorectal cancer (TOPIC study).

Little is known about the clinical impact of salvage panitumumab with irinotecan for metastatic colorectal cancer (mCRC) patients. The present study conducted a single-arm, multicenter phase II trial for mCRC with skin toxicity prevention program. The subjects were mCRC patients with wild-type KRAS, who showed resistance to fluoropyrimidine, oxaliplatin and irinotecan. Panitumumab was administered at a dose of 6 mg/kg every 2 weeks by intravenous infusion over 60 min, and irinotecan was administered at a dose of 100-180 mg/m2 every 2 weeks by intravenous infusion over 90 min, depending on the preceding treatment dose. To prevent skin toxicities, a moisturizer was applied and oral antibiotics (100 mg minocycline twice daily) were initiated for 6 weeks. The primary endpoint was the response rate (RR) determined by independent reviewers. Secondary endpoints were the disease control rate (DCR), progression-free survival (PFS) time, overall survival (OS) time and adverse events. A total of 35 patients were enrolled between October 2010 and March 2012. The median age was 61 years (range, 41-76 years), with 25 male and 10 female patients. The initial irinotecan dose was 150 mg/m2 in 19 patients and 180 mg/m2 in 1 patient. The remaining patients were treated with ≤120 mg/m2. A central review indicated a partial response in 8 patients (22.9%) and stable disease in 6 patients (17.1%), with an RR of 22.9% (95% confidence interval, 12.1-39.0) and a DCR of 40%. The RR of the patients with standard-dose irinotecan (150 or 180 mg/m2) was 30%, although that of low-dose irinotecan (100-120 mg/m2) was 13%. The median PFS time was 2.7 months, and the median OS time was 6.3 months. A grade 3 or above acne-like rash developed in 25.7% of patients. In conclusion, panitumumab and irinotecan as salvage therapy for mCRC KRAS wild-type patients with skin toxicity prevention exhibits limited efficacy. In particular, the effect of low-dose irinotecan with panitumumab appears to be clinically insignificant. Routine use of skin toxicity prevention is currently under evaluation.

Impact of UGT1A1 genotype upon toxicities of combination with low-dose irinotecan plus platinum.

Irinotecan-induced severe toxicities are possibly related to UGT1A1*6 and *28 genotypes. However, the correlation between UGT1A1 polymorphisms and the risk of toxicities induced by low-dose irinotecan plus platinum combination therapy still remains controversial. This prospective observational study aimed to examine the correlation between UGT1A1 genotypes and clinical outcomes of low-dose irinotecan (median 60 mg/m(2) , range 25-115 mg/m(2) ) plus platinum in Japanese patients with solid tumors. Toxicity profiles were compared between UGT1A1 SNP heterozygotes (hetero-group) and patients with homozygous SNP profile (*6/*6, *28/*28 and *6/*28). Logistic regression models were used to identify independent risk factors for these toxicities. A total of 331 patients were enrolled: 84% with hetero-group and 16% with homo-group. Although the initial irinotecan dose was similar, the dose intensities during the three cycles were significantly lower in the homo-group (P < 0.01). Grade 3/4 hematological toxicities were significantly more frequent in the homo-group. Multivariable analysis identified UGT1A1 genotype (P < 0.01) as an independent factor for grade 4 hematological toxicity in the first treatment cycle. UGT1A1 genotype has a major impact on the increased risk of severe hematological toxicities, even in low-dose irinotecan regimens. UGT1A1 genotypes are useful biomarkers for predicting severe hematological toxicities in patients treated with irinotecan plus platinum analog.

Efficacy and safety of FOLFIRI regimen in elderly versus nonelderly patients with advanced colorectal and gastric cancer.

701 Background: Irinotecan-based chemotherapy is a standard backbone in patients (pts) with advanced colorectal (CRC) or gastric cancer (GC). However, there is still a paucity of information concerning the efficacy and safety of irinotecan-based regimen in elderly pts. Methods: Using pt cohort (N = 1,545) of the UGT1A1 genotype study (Kim KP, et al. J Clin Oncol 33, 2015 (suppl; abstr 3600)), we performed subgroup analysis comparing the efficacy and safety between elderly (age ≥ 70 years, median 73 years, N = 245) and non-elderly ( &lt; 70 years, median 57 years, N = 1,300) pts with advanced CRC or GC who received first- or second-line FOLFIRI chemotherapy. Results: In both CRC (N = 934) and GC cohorts (N = 611), elderly pts received significantly lower dose of irinotecan (CRC: mean 74.8% vs. 80.9%, P &lt; 0.001; GC: 72.4% vs. 76.2%, P = 0.018) and infusional 5-fluorouracil (CRC: 61.6% vs. 71.8%, P &lt; 0.001; GC: 47.1% vs. 55.8%, P = 0.004). However, the response rate was similar between elderly and non-elderly pts in both CRC (28.7% vs. 32.9%, P = 0.347) and GC cohorts (22.9% vs. 18.3%; P = 0.369). The progression-free survival was also similar between the two age groups in both CRC (median 27.9 vs. 29.1 weeks, P = 0.202) and GC cohorts (20.1 vs. 17.0 weeks, P = 0.407). In addition, the overall survival was comparable between the two age groups in both CRC (81.9 vs. 91.8 weeks, P = 0.965) and GC cohorts (33.6 vs. 49.3 weeks, P = 0.085). In both cohorts, asthenia was significantly more frequent in elderly pts, while nausea and vomiting were significantly more frequent in non-elderly pts. In CRC cohort, grade 3-4 toxicities that were significantly more frequent in elderly pts were asthenia (1.3% vs. 0.2% per cycle, P &lt; 0.001), mucositis (0.4% vs. 0.1%, P = 0.021), and anorexia (0.8% vs. 0.2%, P = 0.005) in CRC cohort. However, in GC cohort, grade 3-4 toxicities were not significantly different between the two age groups. Conclusions: Despite relatively lower dose intensity in elderly pts, efficacy of FOLFIRI regimen in this subset was comparable to that of non-elderly pts. FOLFIRI regimen was relatively well tolerated in elderly pts. Taken together, FOLFIRI is a considerable standard backbone in elderly pts with advanced CRC or GC.