Irinotecan Dose Escalation Research Articles

Comparison of UGT1A1 Polymorphism as Guidance of Irinotecan Dose Escalation in RAS Wild-Type Metastatic Colorectal Cancer Patients Treated With Cetuximab or Bevacizumab Plus FOLFIRI as the First-Line Therapy.

Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) polymorphism plays a crucial role in the increased susceptibility and toxicity of patients to irinotecan. This retrospective, observational study compared the clinical outcomes and adverse events (AEs) in RAS wild-type metastatic colorectal cancer (mCRC) patients treated with cetuximab or bevacizumab plus FOLFIRI with UGT1A1 genotyping and irinotecan dose escalation as the first-line therapy. In total, 173 patients with mCRC with RAS wild-type were enrolled. Among them, 98 patients were treated with cetuximab, whereas 75 patients were treated with bevacizumab. All patients received irinotecan dose escalation based on UGT1A1 genotyping. We compared the progression-free survival (PFS), overall survival (OS), objective response rates (ORRs), disease control rates (DCRs), metastatectomy, and severe adverse events (SAEs) between the two groups. The clinical effects of primary tumor sidedness and target therapy crossover were further analyzed. Over a median follow-up of 23.0 months [interquartile range (IQR), 15.0–32.5 months], no significant differences were observed between the cetuximab and bevacizumab groups in PFS [18.0 months vs. 14.0 months; 95% confidence interval (CI), 0.517–1.027; hazard ratio (HR), 0.729; p = 0.071], OS (40.0 months vs. 30.0 months; 95% CI, 0.410–1.008; HR, 0.643; p = 0.054), ORR (65.3% vs. 62.7%; p = 0.720), DCR (92.8% vs. 86.7%; p = 0.175), metastatectomy (36.7% vs. 29.3%; p = 0.307), and SAEs (p = 0.685). Regardless of primary tumor sidedness and target therapy crossover, no significant differences were noted in efficacy and safety between the two groups (all p > 0.05). Our results revealed that patients with wild-type RAS mCRC, regardless of biologics, with UGT1A1 genotyping can tolerate escalated doses of irinotecan and potentially achieve a more favorable clinical outcome without significantly increased toxicity.

Clinical Outcomes of Patients with Peritoneal Metastasis-Only Colorectal Cancer Treated with First-Line Bevacizumab and FOLFIRI Through Irinotecan Dose Escalation According to UGT1A1 Polymorphism: Compared to Liver Metastasis-Only, and Lung Metastasis-Only.

BackgroundThe prognosis of metastatic colorectal cancer (mCRC) depends on the metastatic site and systemic therapy regimen. Peritoneal metastases are associated with a relatively unfavorable prognosis among patients with mCRC. In this article, we present the treatment outcomes of patients with peritoneal carcinomatosis (PC)-only, liver metastasis (LiM)-only, and lung metastasis (LuM)-only CRC.MethodsOverall, 206 mCRC patients with single-site metastasis and who had received treatment from January 2014 to December 2018 were recruited. Among 206 patients with mCRC, 15 had PC-only mCRC, 145 had LiM-only mCRC, and 46 had LuM-only mCRC. They attended regular follow-ups until November 2020, and the median follow-up period was 24.7 months (5.1–41.3 months). Patients’ characteristics, including clinical data, gene mutation profiles, and clinical outcomes, were evaluated. All patients with PC-only CRC were treated with first-line bevacizumab and FOLFIRI, and the irinotecan dose escalation depended on UGT1A1 polymorphism.ResultsOf the 206 patients, no statistical difference was observed between the PC-only, LiM-only, and LuM-only groups in terms of age, primary tumor location, RAS mutation status, BRAF mutation status, and epidermal growth factor receptor overexpression (all P > 0.05). Patients with PC-only CRC had a median progression-free survival (mPFS) of 18.0 months and a median overall survival (mOS) of 24.6 months. Patients with LiM-only or LuM-only CRC had mPFS of 18.2 and 26.6 months and mOS of 25.0 and 44.5 months, respectively. No significant differences regarding PFS and OS (both P > 0.05) between the three groups of patients with mCRC were observed.ConclusionOur study revealed that in patients with PC-only mCRC treatment of first-line bevacizumab and FOLFIRI through irinotecan dose escalation according to UGT1A1 polymorphism could confer such patients with comparable outcomes to that of patients with LiM-only and LuM-only mCRC.

Effectiveness and Cost-Utility Analysis of Different Doses of Irinotecan Plus Bevacizumab in Patients With Metastatic Colorectal Cancer: A Long-Term and Prospective Cohort Study.

ObjectivePatients with metastatic colorectal cancer (mCRC) had oncological benefits with irinotecan dose escalation of FOLFIRI regimen combined with bevacizumab according to UGT1A1 genotypes in our previous study. In the current study, we performed a quality of life (QOL) outcome evaluation and cost-utility analysis of different irinotecan dose regimens in patients with mCRC.Materials and MethodsWith inverse probability-of-treatment weighting (IPTW) matching on all covariates, 75 patients with dose escalation of irinotecan (study group) and 121 patients with the recommended dose of irinotecan (control group) were recruited between October 2015 and December 2019. The QOL outcome measures were Functional Assessment of Cancer Therapy-Colorectal, Beck Anxiety Inventory, Beck Depression Inventory, and SF-36; cost-utility outcome measures were medical direct costs, quality-adjusted life-years (QALYs), and incremental cost-utility ratios (ICURs).ResultsAll mCRC patients exhibited a significant decrease in both emotional wellbeing and depression from pretherapeutic period to posttherapeutic 6th month (P < 0.05); however, from the posttherapeutic 1st year to the 2nd year, improvement in most QOL measures was significantly better in the study group than in the control group (P < 0.05). Over a 2-year time period, the study group had higher total medical direct costs than the control group (US$ 54,742 ± 14,013 vs. US$ 54,608 ± 9,673) and higher average QALYs gained (1.88 vs. 1.65), with an ICUR of US$ 583 per QALY gained.ConclusionFor patients with mCRC, irinotecan dose escalation appeared cost-effective with considerable QOL improvements during the study period. Further randomized, multi-institutional controlled trials are warranted to corroborate these results.

UGT1A1 Polymorphism for Irinotecan Dose Escalation in Patients with BRAF-Mutated Metastatic Colorectal Cancer Treated with First-Line Bevacizumab and FOLFIRI.

Background Patients with metastatic colorectal cancer (mCRC) and BRAF V600E mutation have a poor prognosis, with a median progression-free survival (PFS) of only 5–7 months after initial therapy. The current standard first-line chemotherapy for these patients includes FOLFOX or FOLFIRI plus bevacizumab. In this study, we explored the effects and oncological outcomes of UGT1A1 polymorphism for irinotecan escalation in patients with BRAF-mutated mCRC. Patients and Methods. This retrospective study included 17 patients with BRAF-mutated mCRC between April 2016 and December 2019. UGT1A1 genotyping was performed on all patients prior to initiating bevacizumab plus FOLFIRI chemotherapy. The primary endpoint was PFS, and the secondary endpoints were toxicity, response rate, disease control rate, and overall survival (OS). Results Fifteen and two patients had UGT1A1 1∗/1∗ and 1∗/28∗, respectively. Eight underwent irinotecan dose escalation with tolerable adverse effects (AEs), and nine maintained an irinotecan dose of 180 mg/m2 or required deescalation to 150 mg/m2 due to intolerable AEs. After a median follow-up period of 15.7 (range, 3–54) months, the median PFS and OS were 9.4 and 15.7 months, respectively. Grade 3/4 AEs were observed in three (6%) patients. The disease control and partial response rates were 64.7% and 11.8%, respectively, indicating that most patients (14, 82.3%) could maintain this as a first-line line therapy with stable disease or proceed to second-line therapy if disease progression occurred, thereby maintaining acceptable performance status. Conclusions The oncological outcomes of patients with BRAF-mutated mCRC treated using FOLFIRI plus bevacizumab with irinotecan dose escalation as a first-line therapy are acceptable with tolerable AEs; this may be a feasible treatment option in such patients. Pretherapeutic UGT1A1 genotyping-guided dose adjustment can achieve favorable outcomes.

Determination of the UGT1A1 polymorphism as guidance for irinotecan dose escalation in metastatic colorectal cancer treated with first-line bevacizumab and FOLFIRI (PURE FIST)

AimUridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) polymorphism plays a crucial role in the increased susceptibility of patients to irinotecan and its toxicity. This study is a multicenter, randomised clinical trial comparing the clinical outcomes and adverse events (AEs) in metastatic colorectal cancer (mCRC) patients treated with bevacizumab plus FOLFIRI with or without UGT1A1 genotyping and irinotecan dose escalation as the first-line therapy. MethodsThe control group received conventional biweekly FOLFIRI plus bevacizumab without UGT1A1 genotyping, whereas the study group received the same regimen with irinotecan dose escalation based on UGT1A1 genotyping. The primary end-point was progression-free survival (PFS), and secondary end-points were overall response rate (ORR), disease control rate (DCR), overall survival (OS), AEs and metastasectomy rate. ResultsOver a median follow-up of 26.0 months (IQR, 17.0–35.0 months), study group (n = 107) was superior to the control group (n = 106) in PFS, OS, ORR, DCR, and metastasectomy rate (all P < 0.05). Furthermore, there were no significant differences in AEs ≥ grade III between the two groups, even with the 1.36-fold increase in the relative dose intensity of irinotecan in the study group. Dose escalation of irinotecan, an independent factor of ORR (P < 0.001) and DCR (P = 0.006), improved PFS in mCRC patients with wild-type and mutant KRAS (P = 0.007 and P = 0.019, respectively). ConclusionThe current study revealed that mCRC patients, regardless of KRAS gene status, with UGT1A1 genotyping can tolerate escalated doses of irinotecan and potentially achieve a more favourable clinical outcome without significantly increased toxicities. Clinical trial registrationNCT02256800.

Regorafenib Plus FOLFIRI With Irinotecan Dose Escalated According to Uridine Diphosphate Glucuronosyltransferase 1A1 Genotyping in Patients With Metastatic Colorectal Cancer.

We analyzed the results of previously treated patients with metastatic colorectal cancer (mCRC) who received regorafenib plus FOLFIRI with the irinotecan dose escalation on the basis of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotyping. Thirteen patients with previously treated mCRC were subjected to UGT1A1 genotyping between October 2013 and June 2015 and were administered regorafenib plus FOLFIRI with irinotecan dose escalation. Patients with UGT1A1*1/*1 and *1/*28 genotypes were administered 180 mg/m2 of irinotecan, whereas those with the UGT1A1*28/*28 genotype were administered 120 mg/m2 of irinotecan. For all patients, the irinotecan dose was increased by 30 mg/m2 every two cycles until grade ≥3 adverse events or severe adverse events developed, following which the dose was reverted to and maintained at the previously tolerated level. The oral regorafenib dose was adjusted to 120 mg/day daily. The median follow-up period was 10.0 months (1.0–21.0 months). The disease control rate was 69.2%, whereas the median progression-free survival and overall survival were 9.5 and 13.0 months, respectively. Our findings indicate that regorafenib plus FOLFIRI with irinotecan dose escalation based on UGT1A1 genotyping in previously treated patients with mCRC and with UGT1A1*1/*1 and UGT1A1*1/*28 genotypes is clinically effective and yields improved oncological outcomes.

A prospective, multicenter, randomized clinical trial of UGT1A1 promoter polymorphism for irinotecan dose escalation in metastatic colorectal cancer patients treated with bevacizumab plus FOLFIRI as the first-line setting (PURE FIST).

625 Background: The polymorphisms of genes encoding drug-metabolizing enzymes can play a crucial role in the increased susceptibility of patients to chemotherapy. This study is a prospective, multicenter, randomized clinical trial to compare the clinical outcomes and adverse events in metastatic colorectal cancer (mCRC) patients treated with bevacizumab plus 5-fluorouracil/leucovorin/irinotecan (FOLFIRI) with or without UGT1A1genotyping and irinotecan dose escalation as the first-line setting (NCT02256800). Methods: The enrolled patients were randomly assigned to one of two groups on the basis of receiving UGT1A1 genotyping or not. The study group receives a biweekly FOLFIRI plus bevacizumab, with irinotecan dose escalation based on UGT1A1 genotyping; whereas the control group receives the conventional biweekly FOLFIRI plus bevacizumab without UGT1A1 genotyping. The primary endpoint was the overall response rate (ORR), and the second endpoint was progression-free survival (PFS), overall survival (OS) and toxicities between the two groups. Results: BetweenAugust 2013 and May 2016, eighty-eight mCRC patients were enrolled, including 45 patients in the study group and 43 patients in the control group. With a median follow up time of 12.5 months (range, 5-30), the ORR was 71.4% vs. 44.2% ( P = 0.011). The PFS was 14.04 ± 1.44 vs. 9.08 ± 0.58 months in study group and control group ( P = 0.195), OS was 19.12 ± 1.24 vs. 14.16 ± 1.04 months ( P = 0.098), and ≥ Gr. III anemia was 2.2% vs. 23.3% ( P= 0.002) in study group and control group, respectively. However, there were no significant differences in ≥ Gr. III leukopenia or diarrhea even though the 1.36 fold relative dose intensity (RDI) in the study group. Conclusions: In the current study, patients with mCRC undergoing UGT1A1 genotyping may receive escalated doses of irinotecan for a potentially more favorable clinical response and outcome, in addition to acceptable toxicities. Such a personalized medicine based on genotyping may be feasible for potentially clinical practice. Clinical trial information: NCT02256800.

Prospective analysis of UGT1A1 promoter polymorphism for irinotecan dose escalation in metastatic colorectal cancer patients treated with bevacizumab plus FOLFIRI as the first-line setting: study protocol for a randomized controlled trial.

BackgroundIrinotecan is approved and widely administered to metastatic colorectal cancer (mCRC) patients; however, it can cause severe toxicities including neutropenia and diarrhea. The polymorphisms of genes encoding drug-metabolizing enzymes can play a crucial role in the increased susceptibility of cancer patients to chemotherapy toxicity. Therefore, we plan to explore the effect of the genetic polymorphism of uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) for irinotecan detoxification in mCRC patients. This trial will compare the clinical outcomes and side effects observed in mCRC patients treated with bevacizumab plus 5-fluorouracil/leucovorin/irinotecan (FOLFIRI) with and without UGT1A1 genotyping and irinotecan dose escalation. A total of 400 mCRC patients were randomized into a study group and a control group.Methods/DesignThis trial is a prospective, multicenter, randomized clinical trial comparing UGT1A1 promoter polymorphism for irinotecan dose escalation in mCRC patients administered with bevacizumab plus FOLFIRI as the first-line setting. The enrolled patients were randomly assigned to one of two groups, a study group and a control group, on the basis of receiving UGT1A1 genotyping or not. The study group receive a biweekly FOLFIRI regimen, with irinotecan dose escalation based on UGT1A1 genotyping; whereas the control group receive the conventional biweekly FOLFIRI regimen without UGT1A1 genotyping. The clinicopathological features, response rates, toxicity, and progression-free survival or overall survival will be compared between the two groups.DiscussionPatients with mCRC undergoing UGT1A1 genotyping may receive escalated doses of irinotecan for a potentially more favorable clinical response and outcome, in addition to comparable toxicities. Such personalized medicine based on genotyping may be feasible for clinical practice.Trial registrationNCT02256800. Date of registration: 3 October 2014. Date of first patient randomized: 16 January 2015

Clinical Implication of UGT1A1 Promoter Polymorphism for Irinotecan Dose Escalation in Metastatic Colorectal Cancer Patients Treated with Bevacizumab Combined with FOLFIRI in the First-line Setting

PURPOSE: This study aimed to identify the efficacy and toxicity of the FOLFIRI regimen (fluorouracil, leucovorin, and irinotecan) with irinotecan dose escalation plus bevacizumab as first-line chemotherapy for metastatic colorectal cancer (mCRC) via UGT1A1 genotyping. METHODS: We administered bevacizumab plus FOLFIRI with irinotecan dose escalation to treat 70 mCRC patients. The UGT1A1 *1/*1 and *1/*28 genotypes started with a 180-mg/m2 dose of irinotecan, and UGT1A1 *28/*28 genotype started with a dose of 120 mg/m2. The dose of irinotecan was escalated at increasing intervals of 20 to 30 mg/m2 until grade 3/4 adverse events (AEs) occurred. The clinical response rate, toxicity, and survival were analyzed. RESULTS: The clinical response and disease control rates of mCRC patients treated with FOLFIRI plus bevacizumab were significantly better in patients with UGT1A1 *1/*1 and *1/*28 genotypes than in patients with UGT1A1 *28/*28 (P = .006 and P < .001, respectively). Grade 3/4 AEs were significantly more common in mCRC patients with the UGT1A1 *28/*28 genotype (P < .001). Progression-free survival was significantly higher in UGT1A1 *1/*1 and *1/*28 patients (P = .002). mCRC patients who underwent metastasectomy achieved better overall survival than those who did not undergo metastasectomy (P = .015). CONCLUSIONS: Our study showed that mCRC patients with UGT1A1 *1/*1 and *1/*28 genotypes could receive escalated doses of irinotecan to obtain a more favorable clinical outcome without significant AEs.

710: Clinical implication of UGT1A1 promoter polymorphism for irinotecan dose escalation in metastatic colorectal cancer patients treated with bevacizumab combined with FOLFIRI in the first-line setting

710: Clinical implication of UGT1A1 promoter polymorphism for irinotecan dose escalation in metastatic colorectal cancer patients treated with bevacizumab combined with FOLFIRI in the first-line setting

Prognostic advantage of irinotecan dose escalation according to uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotyping in patients with metastatic colorectal cancer treated with bevacizumab combined with 5-fluorouracil/leucovorin with irinotecan in a first-line setting

This study compared the clinical responses of patients with metastatic colorectal cancer (mCRC) with 5-fluorouracil/leucovorin with irinotecan (FOLFIRI) plus bevacizumab therapy either with or without uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotyping and irinotecan dose escalation. Of 107 total patients with mCRC, 79 were classified as the study group and 28 as the control group. The study group received irinotecan dose escalation based on UGT1A1 genotyping whereas the control group did not. Clinicopathologic features, response rates, and survival were compared for the 2 groups. The clinical response rate of patients with mCRC treated with FOLFIRI plus bevacizumab under UGT1A1 genotyping and irinotecan dose escalation was significantly better than that of those without these prospective tests and dose escalation (P = 0.028). Both progression-free survival (PFS) and overall survival were significantly greater in clinical responders than nonresponders (both, P < 0.001), and PFS was significantly greater among the study group patients than among the control group patients, with a median PFS of 12.2 months vs 9.4 months (P = 0.025). Grade 3/4 adverse events were not significantly different between the 2 groups (P = 0.189). Patients with mCRC undergoing UGT1A1 genotyping may receive escalated doses of irinotecan to obtain a better clinical response/outcome with comparable toxicities.

Prospective analysis of UGT1A1 promoter polymorphism for irinotecan dose escalation in metastatic colorectal cancer patients treated with bevacizumab combined with FOLFIRI as the first-line setting.

491 Background: Infusional fluorouracil/leucovorin plus irinotecan-based regimen (FOLFIRI) with bevacizumab has been widely used as first-line treatment for patients with metastatic colorectal cancer (mCRC). We prospectively analyzed the influence of uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1) genotyping for irinotecan dose escalation in mCRC patients treated with combination of FOLFIRI and bevacizumab as the first-line setting. Methods: A total of 65 mCRC patients undergoing first-line treatment with FOLFIRI combined with bevacizumab were analyzed. Genotypes were performed by analyzing the sequence of TATA box of UGT1A1 of genomic DNA from the patients. Genotype and clinical parameters were compared by univariate analysis. The irinotecan dose is escalating form 180 mg/m2 to 260 mg/m2 in UGT1A1 6/6 or 6/7, and from 120 mg/m2 to 210 mg/m2 in UGT1A17/7. Results: The response rate was observed in 44 of 60 UGT1A1 6/6 or 6/7 (73.3%) in comparison to 1 of 5 UGT1A1 7/7 (20%) patients (p=0.013). The grade III-IV adverse events (AE) was observed in 4 of 60 UGT1A1 6/6 or 6/7 (6.7%) in comparison to 3 of 5 UGT1A1 7/7 (60%) patients (p&lt;0.001), but it was not different between age of ≥ 70 and &lt; 70 (p=0.559). Fifteen of 60 (20%) patients with UGT1A1 6/6 or 6/7 could be performed with liver or lung metastaectomy in comparison to none of 5 patients with UGT1A1 7/7. In addition, the disease control rate was significantly higher in irinotecan dose of ≥ 210 mg/m2 than irinotecan dose of &lt; 210 mg/m2(p=0.015). Conclusions: UGT1A1 promoter polymorphism was found to be predictive of toxicity and efficacy in mCRC patients with first-line treatment of FOLFIRI combined with bevacizumab. The higher dose of irinotecan (≥ 210 mg/m2) may achieve a better disease control rate but do not increase the incidence of GR III-IV AE in mCRC patients of age ≥ 70 years.

Phase II and UGT1A1 genotype study of irinotecan dose escalation as salvage therapy for advanced gastric cancer

Background:To assess the efficacy and safety of individualised dose optimisation of irinotecan monotherapy as salvage treatment for advanced gastric cancer (AGC).Methods:A total of 43 patients were enrolled. Intravenous irinotecan (350 mg m−2) was administered every 3 weeks. The dose was increased (425 mg m−2 and 500 mg m−2) or decreased (250 mg m−2) depending on patient tolerance. UGT1A1 genotypes were determined by direct sequencing of genomic DNA extracted from peripheral blood.Results:A total of 183 cycles of irinotecan were administered, with a median of four cycles per patient. The overall response rate was 9.3%, and the disease control rate was 62.8%. Median time to disease progression was 2.8 months, and median overall survival was 8.0 months. Grade 3–4 neutropenia was the most common toxicity (53.5%), and febrile neutropenia was the least common toxicity (4.6%). Compared with defective allele groups, UGT1A1 *1/*1 was associated with a lower incidence of grade 3–4 neutropenia during the first cycle (P=0.018).Conclusion:Individualised irinotecan dose escalation based on patient tolerance was not associated with increased toxicity and shows modest activity as salvage chemotherapy for AGC. The role of UGT1A1 genotype in clinical toxicity requires further evaluation.

Current place of high-dose irinotecan chemotherapy in patients with metastatic colorectal cancer

Irinotecan has an important place in the treatment of metastatic colorectal cancer. It was initially administered as monotherapy, but is now generally used in combination with 5-fluorouracil or targeted therapies (cetuximab or bevacizumab), with various doses. We here review the main studies assessing irinotecan doses escalation, and discuss the potent advantages of this escalation. Several studies have demonstrated a dose-intensity relationship for irinotecan, and high doses (up to 600 mg/m2 as monotherapy, 260 mg/m2 in combination therapy) have been used with satisfactory safety and higher objective response rates. It is possible that, in practice, some patients receive insufficient doses of irinotecan. Dose escalation could be considered in carefully selected patients: young patients with a good performance status and normal liver function. This approach could be useful in patients with liver metastases, which may become resectable in the case of a major tumour response. It is wise to perform UGT1A1 genotyping prior to dose escalation to detect patients at high risk of toxicity (genotype 7/7). The role of another laboratory parameter, which needs to be evaluated is the KRAS status of the tumour. A KRAS mutation confers resistance to cetuximab, which reduces treatment options, especially in first-line. However, in the CRYSTAL trial comparing FOLFIRI to FOLFIRI-cetuximab as first-line therapy, the presence of a KRAS mutation did not appear to influence the efficacy of FOLFIRI. The value of irinotecan dose escalation needs to be determined in this setting. Irinotecan dose escalation is potentially of interest in highly selected patients, but this concept is only based on phase I or II trials and must be validated by a randomized trial. Its value regarding other regimens such as FOLFIRINOX or combinations with targeted therapies also needs to be determined.

A phase I and pharmacokinetic (PK) study of high dose selenomethionine (SLM) in combination with irinotecan (IRI) in patients with advanced solid tumors

2080 Background: SLM, an organic selenium (Se) compound, potentiates IRI activity, protects against toxicity, and allows dose-escalation of IRI in pre-clinical models. IRI dose-escalation in mice models was possible only in association with serum Se concentrations > 1200ng/ml. We initiated a phase I study of daily SLM with weekly IRI to investigate: 1) the maximum tolerated dose (MTD) of IRI when combined with high dose SLM; 2) the pharmacokinetics (PK) of both compounds. Methods: IRI was escalated in a standard 3+3 design. SLM was administered at a fixed dose of 2200 μg/day starting 1 week before the 1st dose of IRI. IRI was administered intravenously weekly x 4 repeated every 6 weeks (1cycle). Dose level (DL) 1 and DL2 consisted of IRI 125mg/m2 and 160mg/m2 respectively. Blood for Se was drawn on days 1, 2, 8, 15, 29 and 50 (and later where possible). Results: 10 evaluable pts were treated on study (M/F: 6/4; median age: 59; ECOG 0/1: 3/7; prior chemo: 10). At DL2, 3 out of 4 pts had G3 diarrhea (DLT). None of the 6 DL1 pts had a DLT (declared MTD). Diarrhea was ≤ G2 (1 pt with G2) and neutropenia ≤ G2 at DL1 except for 1 pt with G4 neutropenia. SLM was associated with mild intermittent garlic-like breath. Se PK showed a suboptimal concentration <1000 ng/ml on day 1 of IRI. The mean Se (SD) serum half-life was 183 (94) h, and CLt/F 0.10 (0.04) L/h. Modeling of data suggests steady state attainment after ∼30 days, with a median Se steady state level of 844 (range 585 -1300) ng/ml. Responses were evaluable in 8 patients: 1 pt with prior IRI-refractory colon cancer had a partial response that is ongoing (11 months +). This patient had complete reversal of total alopecia upon built up of Se concentrations > 1200 ng/ml. 4pts had prolonged stable disease (Colon, NSCL, pancreatic, and gastric cancer). Conclusions: The administration of SLM at 2200 μg PO QD is safe but does not allow IRI escalation > 125mg/m2/week. Unexpected responses and disease stabilizations were noted at the MTD suggesting possible synergy between SLM and IRI. The inability to escalate IRI may be related to suboptimal concentrations of Se on D1 of IRI. SLM escalation in combination with fixed dose IRI is ongoing. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Sabinsa Sabinsa

Phase I trial of cisplatin, infusional 5-FU and irinotecan in advanced gastric cancer

2117 Background: There is not a standard chemotherapy treatment for advanced gastric cancer. Irinotecan/Cisplatin is one of the new combinations showing promising activity in this disease. Methods: This study aim to determine maximum tolerated dose (MTD) of a three drugs combination chemotherapy in patients with locally advanced non rescetable or metastatic gastric cancer. Other advanced solid tumors not previously treated for which the proposed chemotherapy is a reasonable therapeutic option could be included. The MTD is defined as the dose at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity (DLT). The recommended phase II dose is defined as the dose preceding the MTD A Phase I trial, started with: Infusional 5-FU: 14 days protacted infusion, days 1 and 22, fixed dose 200 mg/m2, weekly cisplatin: fixed dose 30 mg/m2, days 1,8,22 and 29. Weekly irinotecan days 1,8,22 and 29, 3 doses levels: 0: 55 mg/m2, 1: 60 mg/m2, 2: 65 mg/m2. Irinotecan dose escalation is allowed if 0/3 or 1/6 patients had limiting toxicity at previous dose level and at least three patients were treated for the entire treatment period in each level. DLT is defined as: G4 neutropenia and trombophenia for five days or more, fever or sepsis with neutropenia and other non-hematological grade 3–4 toxicity (excluding alopecia, anaemia and vomiting). Results: Three patients were included in first level, 2 males / 1 female (ages: 21,22,56). Two advanced gastric adenocarcinoma and one hepatocarcinoma Toxicity: diarrhea grade 2: one patient, asthenia grade 2: one patient, nausea grade 2: one patient. No MTD toxicity was found. Conclusions: In December 2003, the first level is completed without DLT. The study is ongoing and there is a patient included in second level. No significant financial relationships to disclose.

Effect of intrapatient dosage escalation of irinotecan on its pharmacokinetics in pediatric patients who have high-grade gliomas and receive enzyme-inducing anticonvulsant therapy.

The authors set out to determine the effect of intrapatient dose escalation of irinotecan on its disposition in pediatric patients with high-grade glioma who received concomitant enzyme-inducing anticonvulsants (EIAs). During Course 1, a 60-minute intravenous infusion of irinotecan (20 mg/m(2) per day) was administered once daily for 5 days on each of 2 consecutive weeks. The authors measured the concentrations of the lactone forms of irinotecan and its metabolites 7-ethyl-10-hydroxycamptothecin (SN-38), SN-38 glucuronide, and 7-ethyl-10-[4-N-(5-aminopeptanoic acid)-1-piperidino]-carbonyloxycamptothecin (APC) in serial plasma samples collected on Days 1 and 12 of Course 1. For the 6 patients who received EIAs but whose SN-38 areas under the concentration-time curve (AUCs) on Day 1 were below clinically significant levels, irinotecan dosage was increased, and subsequent pharmacokinetic studies were performed. Thirty-five patients were enrolled. The rate of irinotecan clearance was greater for patients who received EIAs than for those who did not (P = 0.0008), whereas systemic exposure to irinotecan (P = 0.02) and SN-38 (P = 0.0001) was lower for those treated with EIAs than for those who were not. Of the 6 patients whose irinotecan dosages were increased, 3 experienced an increase in the SN-38 AUC between Days 1 and 12. For 1 patient, the SN-38 AUC on Day 12 was lower than on Day 1; this result likely was due to an increased dose of EIAs during the same period. Despite irinotecan dose escalation to 60 and 80 mg/m(2), the SN-38 AUCs for 2 patients did not increase to clinically significant levels. The type and grade of toxicity did not differ between the two patient groups. Increasing the dosage of irinotecan increased the SN-38 AUC in some patients who received concomitant EIA therapy.