Impact of UGT1A1 genetic polymorphism on toxicity in unresectable pancreatic cancer patients undergoing FOLFIRINOX

Efficacy and safety of neoadjuvant nab-paclitaxel plus gemcitabine therapy in patients with borderline resectable pancreatic cancer: A multicenter single-arm phase II study (NAC-GA trial)

Background

Nab-paclitaxel plus gemcitabine is a standard treatment for metastatic/locally advanced pancreatic cancer. The effectiveness of neoadjuvant therapy with nab-paclitaxel plus gemcitabine (GnP-NAT) in patients with borderline resectable pancreatic cancer (BRPC) remains unclear.

Patients and Methods

This single-arm phase II trial included 61 patients with BRPC that were treated with two cycles of GnP-NAT, (nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2), on days 1, 8, and 15 over a 4-week period, which comprised one cycle. The primary endpoint was overall survival time. In the absence of disease progression, patients underwent planned pancreatectomy.

Results

Median overall survival, the primary endpoint, was 25.2 months, and the median recurrence-free survival was 12.3 months. The overall rate of grade 3/4 events was 73.8%. One patient, who had a history of radiation therapy for past esophageal cancer, died from exacerbation via pneumonia. The overall resection rate was 73.8% (n = 45), and the R0 resection rate was 63.9% (n = 39). Overall, postoperative complications were found in 19 patients (42%) with 24 events, and nine patients (20%) with nine events ≥ grade IIIa, based on Dindo's classification.

Conclusions

This protocol treatment is thought to be a feasible, safe, and promising treatment regimen, but we caution against its use in patients with a history of interstitial lung disease and/or prior pulmonary irradiation. The survival data from this study suggest the need for further investigations of GnP-NAT efficacy in patients with BRPC, as well as prospective evaluation of adverse events.

Clinical Trial Registration

UMIN Clinical Trials Registry, UMIN000024154 and ClinicalTrials.gov, NCT02926183.

Impact of Granulocyte Colony-Stimulating Factor (G-CSF) on the Outcomes of Patients With Metastatic Pancreatic Adenocarcinoma (MPA) During First-Line Treatment With FOLFIRINOX: A Single-Center Retrospective Analysis

INTRODUCTION

The role of primary prophylaxis (PP) with granulocyte colony-stimulating factor (G-CSF) for patients with metastatic pancreatic adenocarcinoma (MPA) treated with FOLFIRINOX is unknown. We aimed to compare the frequencies of grades 3 or 4 neutropenia (G3/4N) and febrile neutropenia (FN) and survival outcomes according to the use of PP.

METHODS

This is a retrospective study. We included patients with pathologically confirmed MPA treated with FOLFIRINOX in first-line. Patients who received primary prophylaxis (PP group) were compared to patients who received secondary or no G-CSF (no-PP group). Overall survival (OS) and progression-free survival (PFS) were evaluated using the standard Cox proportional hazard model. To account for potential biases, we performed sensitivity analyses excluding patients who received secondary prophilaxis and treating G-CSF as a time-dependent covariate in extended Cox proportional hazard models.

RESULTS

The study population consisted of 123 patients. PP was used by 75 patients (61.0%). G3/4 N occurred more frequently among patients without PP (10.7 vs 41.7%; P < .001). There was no difference in the frequency of FN between groups (5.3 vs 8.3%; P = .710). In multivariate analysis, PP was associated with a trend toward improved OS (HR = .66; 95% confidence interval [95% CI] .41 - 1.07; P = .094). In the multivariate model excluding patients with secondary prophylaxis (HR = .54; 95% CI 0.32 - .91; P = .022) and in the time-dependent model (HR = .47; 95% CI 0.28 - .80; P = .005), PP was associated with statistically superior OS.

CONCLUSIONS

Despite the reduction in the frequency of G3/4N, the risk of FN among patients treated with FOLFIRINOX without G-CSF is too low to justify its use in a routine basis. However, given the potential of G-CSF to improve survival in this setting, further studies are warranted to assess its role during treatment with FOLFIRINOX for patients with MPA.

Incidence of and risk factors for severe neutropenia during treatment with the modified FOLFIRINOX therapy in patients with advanced pancreatic cancer

Although FOLFIRINOX (l-Leucovorin/5-FU/Irinotecan/Oxaliplatin) is established as one of the standard therapies for patients with metastatic pancreatic cancer, the modified FOLFIRINOX (mFOLFIRINOX) is often used in clinical practice to reduce the incidence of toxicities. Febrile neutropenia (FN) and severe neutropenia during FOLFIRINOX are especially frequently observed in Japanese patients. In this study, we evaluated the incidence of FN and severe neutropenia, and explored the risk factors for severe neutropenia in patients receiving treatment with mFOLFIRINOX. The data of patients who had received mFOLFIRINOX between December 2013 and December 2014 at the National Cancer Center Hospital East were reviewed retrospectively. We graded the neutropenia severity and defined ≥ Grade 3 neutropenia as severe neutropenia. Univariate and multivariate analysis were undertaken to evaluate the associations with risk of development of severe neutropenia. A total of 122 patients were enrolled in this study. Sixty two patients (51%) and 10 patients (8%) developed severe neutropenia and FN, respectively. Multivariate analysis identified a low baseline white blood cell count (odds ratio [OR], 14.50; 95% confidence interval (CI), 3.27–111.14; p = 0.002) and presence of heterozygosity for UGT1A1*28 or UGT1A1*6 polymorphism (OR, 2.84; 95% CI, 1.18–7.17; p = 0.023) as independent risk factors for severe neutropenia. The incidences of severe neutropenia and FN in patients receiving mFOLFIRINOX in our clinical practice were comparable to previous reports. The risk factors for severe neutropenia in patients receiving mFOLFIRINOX were a low baseline white blood cell count and presence of heterozygosity for UGT1A1*28 or UGT1A1*6 polymorphism.

The influence of UGT1A1 polymorphisms on modified FOLFIRINOX dose in double-variant-type patients with advanced pancreatic cancer

BACKGROUND

UGT1A1 polymorphisms should be considered when using irinotecan-containing regimens, especially in patients with a double-variant-type (DV), including homozygous for UGT1A1*28 and UGT1A1*6 and heterozygous for both UGT1A1*28 and UGT1A1*6. We investigated the safety and efficacy of modified FOLFIRINOX (mFOLFIRINOX) (irinotecan 80 mg/m2) in patients having DV.

METHODS

Patients with advanced pancreatic cancer who had received FOLFIRINOX between January 2015 and December 2019 were included in this study. Non-DV patients received the standard mFOLFIRINOX (irinotecan 150 mg/m2) as first-line (non-DV1) or second-line therapy (non-DV2); however, DV patients received mFOLFIRINOX (irinotecan 80 mg/m2) as the second-line therapy (DV2). We retrospectively evaluated the safety and efficacy of the lowered irinotecan dose in the DV2 group relative to the non-DV1 (safety) or non-DV2 (safety and efficacy) groups.

RESULTS

A total of 235 patients were eligible for this study with 118 patients in the non-DV1, 106 in the non-DV2, and 11 in the DV2 groups. Major grade 3-4 adverse events were neutropenia (33.9, 31.1, and 18.2%) and febrile neutropenia (6.8, 3.8, and 9.1%) in the non-DV1, non-DV2, and DV2 groups, respectively. The median progression-free survival was 3.4 months in the non-DV2 group, and 4.4 months in the DV2 group. The overall survival from the date of starting second-line chemotherapy was 8.8 months in the non-DV2 group and 11.5 months in the DV2 group.

CONCLUSIONS

Based on our findings, the safety and efficacy of mFOLFIRINOX (irinotecan 80 mg/m2) in DV patients were comparable with the standard mFOLFIRINOX (irinotecan 150 mg/m2) in non-DV patients.

A phase 1b study of OXIRI in pancreatic adenocarcinoma patients and its immunomodulatory effects

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal and debilitating disease with limited therapeutic options. The aim of this clinical study was to evaluate the safety, efficacy and pharmacokinetics of a novel regimen comprised of metronomic oxaliplatin (O), chronomodulated capecitabine (X) and UGT1A1 genotype-guided dosing of irinotecan (IRI) [OXIRI] as well as its immunomodulatory effects. Thirty-six patients were enrolled into either dose-escalation or expansion cohorts. In the dose escalation phase, capecitabine doses (2000, 2650, 3500 and 4500 mg/day) were administered at midnight on days 1 to 14 while oxaliplatin and irinotecan were intravenously infused at fixed doses of 50 and 75 mg/m2 respectively on days 1, 8 in a 21-day cycle. The maximum tolerated dose of capecitabine was 2650 mg/day and the most common grade 3 adverse events were neutropenia (30.6%) and diarrhea (13.9%). No grade 4 toxicity was observed. UGT1A1-genotype directed dosing resulted in similar exposure levels of irinotecan, SN-38 and SN-38G in all patients. Objective response rate was 22.2%. Median overall survival and progression-free survival were 8.1 and 5.2 months, respectively. Exploratory immunoprofiling by flow cytometry and quantitative spatial localization analysis of infiltrated immune cells performed on biopsy and plasma samples revealed significant declines in CCL22, CCL2 and TNFα levels at end of first cycle and an active host immune response. Our study showed that OXIRI was well-tolerated and exhibited good efficacy, with immunomodulatory effects. It may be considered as an alternative to FOLFIRINOX in patients intolerant to the latter.

Modern developments in germline pharmacogenomics for oncology prescribing

The integration of genomic data into personalized treatment planning has revolutionized oncology care. Despite this, patients with cancer remain vulnerable to high rates of adverse drug events and medication inefficacy, affecting prognosis and quality of life. Pharmacogenomics is a field seeking to identify germline genetic variants that contribute to an individual's unique drug response. Although there is widespread integration of genomic information in oncology, somatic platforms, rather than germline biomarkers, have dominated the attention of cancer providers. Patients with cancer potentially stand to benefit from improved integration of both somatic and germline genomic information, especially because the latter may complement treatment planning by informing toxicity risk for drugs with treatment-limiting tolerabilities and narrow therapeutic indices. Although certain germline pharmacogenes, such as TPMT, UGT1A1, and DPYD, have been recognized for decades, recent attention has illuminated modern potential dosing implications for a whole new set of anticancer agents, including targeted therapies and antibody-drug conjugates, as well as the discovery of additional genetic variants and newly relevant pharmacogenes. Some of this information has risen to the level of directing clinical action, with US Food and Drug Administration label guidance and recommendations by international societies and governing bodies. This review is focused on key new pharmacogenomic evidence and oncology-specific dosing recommendations. Personalized oncology care through integrated pharmacogenomics represents a unique multidisciplinary collaboration between oncologists, laboratory science, bioinformatics, pharmacists, clinical pharmacologists, and genetic counselors, among others. The authors posit that expanded consideration of germline genetic information can further transform the safe and effective practice of oncology in 2022 and beyond.

Characteristics and Clinical Implication of UGT1A1 Heterozygous Mutation in Tumor

BACKGROUND

The literature recommends that reduced dosage of CPT-11 should be applied in patients with UGT1A1 homozygous mutations, but the impact of UGT1A1 heterozygous mutations on the adverse reactions of CPT-11 is still not fully clear.

METHODS

A total of 107 patients with UGT1A1 heterozygous mutation or wild-type, who were treated with CPT-11 from January 2018 to September 2021 in Peking University Third Hospital, were retrospectively enrolled. The adverse reaction spectra of patients with UGT1A1*6 and UGT1A1*28 mutations were analyzed. Adverse reactions were evaluated according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) 5.0. The efficacy was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The genotypes of UGT1A1*6 and UGT1A1*28 were detected by digital fluorescence molecular hybridization.

RESULTS

There were 43 patients with UGT1A1*6 heterozygous mutation, 26 patients with UGT1A1*28 heterozygous mutation, 8 patients with UGT1A1*6 and UGT1A1*28 double heterozygous mutations, 61 patients with heterozygous mutation at any gene locus of UGT1A1*6 and UGT1A1*28. Logistic regression analysis showed that the presence or absence of vomiting (P=0.013) and mucositis (P=0.005) was significantly correlated with heterozygous mutation of UGT1A1*28, and the severity of vomiting (P<0.001) and neutropenia (P=0.021) were significantly correlated with heterozygous mutation of UGT1A1*6. In colorectal cancer, UGT1A1*6 was significantly correlated to diarrhea (P=0.005), and the other adverse reactions spectrum was similar to that of the whole patient cohort, and efficacy and prognosis were similar between patients with different genotypes and patients treated with reduced CPT-11 dosage or not.

CONCLUSIONS

In clinical use, heterozygous mutations of UGT1A1*6 and UGT1A1*28 are related to the risk and severity of vomiting, diarrhea, neutropenia and mucositis in patients with Pan-tumor and colorectal cancer post CPT-11 therpy. In colorectal cancer, UGT1A1*6 is significantly related to diarrhea post CPT-11 use, efficacy and prognosis is not affected by various genotypes or CPT-11 dosage reduction.

Impact of UGT1A1 Polymorphisms on Febrile Neutropenia in Pancreatic Cancer Patients Receiving FOLFIRINOX: A Single-Center Cohort Study

FOLFIRINOX (oxaliplatin, leucovorin, irinotecan, and 5-fluorouracil) is a first-line chemotherapy for metastatic pancreatic cancer (PC). Chemotherapy-induced neutropenia is one of the most serious adverse events associated with advanced PC. Although UGT1A1 polymorphisms are associated with the metabolism of irinotecan, their role as surrogate markers for FOLFIRINOX-induced neutropenia has not been confirmed. We investigated risk factors for FN-in particular, UGT1A1 polymorphisms-in PC patients receiving FOLFIRINOX, using a single-center cohort registry. To investigate the association between UGT1A1 polymorphisms and FN, we divided patients into three groups based on the predicted UGT1A1 phenotype: extensive metabolizer (EM) vs. intermediate metabolizer (IM) vs. poor metabolizer (PM). A total of 154 patients (FN group (n = 31) vs. non-FN group (n = 123)) receiving first-line FOLFIRINOX were identified between December 2017 and July 2020. The Cox regression analysis showed that female sex (HR: 2.20; p = 0.031), Eastern Cooperative Oncology Group performance status = 1 (HR: 2.83; p = 0.008), UGT1A1 IM (HR: 4.30; p = 0.004), and UGT1A1 PM (HR: 4.03; p = 0.028) were statistically significant risk factors for FN. We propose that UGT1A1 is the strongest predictive factor for FN and that this gene should be screened prior to the administration of chemotherapy.

Comparative efficacy of modified FOLFIRINOX, gemcitabine plus capecitabine and gemcitabine plus nab-paclitaxel as adjuvant treatment for resected pancreatic cancer: a Bayesian network meta-analysis

Background

There are no head-to-head comparisons evaluating the efficacy of the main polychemotherapy regimens used for patients with pancreatic cancer in the adjuvant setting. We aimed to describe the relative efficacy of modified FOLFIRINOX (mFOLFIRINOX), gemcitabine plus capecitabine (GEM-CAP) and gemcitabine plus nab-paclitaxel (GEM-NAB) in this setting using a Bayesian network approach.

Methods

We collected data from the ESPAC-4, PRODIGE 24 and APACT trials. Disease-free survival (DFS), according to the investigators, and overall survival (OS) for the three polychemotherapy regimens were compared using gemcitabine as the reference arm. We ran Markov chain Monte Carlo simulations with a fixed-effect model to generate the posterior distribution of the hazard ratios (HRs) using non-informative priors. Relative efficacy was measured by HRs, surface under cumulative ranking and rankograms.

Results

mFOLFIRINOX was the chemotherapy regimen most likely to be the most effective in the adjuvant setting (98.9% and 89.6% probability for DFS and OS, respectively). GEM-NAB marginally improved DFS (HR = 0.97, 95% credible interval (95% CrI) = 0.77–1.21) and OS (HR = 0.98, 95% CrI = 0.76–1.25) when compared to GEM-CAP. However, GEM-NAB had the highest chances of being the second most active chemotherapy regimen (61.4% and 52.5% probability for DFS and OS, respectively), whereas GEM-CAP was less likely to represent the second most active regimen (37.7% and 40.1% probability for DFS and OS, respectively).

Conclusion

For patients eligible and fit enough to undergo adjuvant treatment with mFOLFIRINOX, this constitutes the treatment of choice. For those with contraindications to mFOLFIRINOX, while both GEM-NAB and GEM-CAP can be considered appropriate alternatives, GEM-NAB is likely the most effective regimen.

Comprehensive pharmacogenetic analysis of DPYD, UGT, CDA, and ABCB1 polymorphisms in pancreatic cancer patients receiving mFOLFIRINOX or gemcitabine plus nab-paclitaxel

Modified FOLFIRINOX (mFOLFIRINOX) and gemcitabine + nab-paclitaxel (GemNab) regimens represent a standard treatment in advanced pancreatic cancer (aPC). DPYD and UGT1A1 variants are relevant predictors of fluoropyrimidine and irinotecan-associated adverse events (AEs). Furthermore, data about the associations between polymorphisms in ABCB and CDA genes and GemNab-related toxicities are still controversial. The present study analyzes the association between DPYD, UGT, ABCB1, CDA variants, and AEs in aPC patients (pts) treated with mFOLFIRINOX or GemNab. Blood samples collected from 104 aPC pts treated with mFOLFIRINOX and 63 with GemNab were tested for DPYD c.1679T>G, IVS14+1G>A, c.2194G>A, c.2846A>T, UGT1A1*28, CDA c.79A>C, and ABCB1 c.1236C>T, c.2677G>T/A, c.3435C>T by real-time PCR and automatic sequencing. In mFOLFIRINOX cohort, DPYD IVS14+1GA genotype was associated with G4 hematological AEs, while the UGT1A1*28 significantly correlated with the risk of thrombocytopenia (p = 0.006). In the GemNab cohort, a significant association between CDA c.79CC and high-grade nausea was observed (p = 0.002). Moreover, the presence of at least a mutant allele in ABCB1 increased the risk of overall hematological AEs (p = 0.01), both further strengthened by the presence of CDA c.79CC (p = 0.0002). DPYD IVS14+1A allele is confirmed to be associated with fluoropyrimidine life-threatening toxicities, and UGT1A1*28 is related with a higher risk of hematologic AEs following irinotecan treatment. CDA c.79C and ABCB1 c.1236T, c.2677T/A, and c.3435T mutant alleles are predictive biomarkers of GemNab-related AEs. All these variants should be considered in aPC pts candidate to mFOLFIRINOX or GemNab treatments.

FOLFIRINOX in advanced pancreatic cancer patients with the double-variant type of UGT1A1 *28 and *6 polymorphism: a multicenter, retrospective study

Background

UGT1A1 *28 and *6 polymorphism is associated with reduced enzyme activity and severe toxicities of irinotecan, especially in patients with homozygous or heterozygous for UGT1A1*28 or *6 polymorphism for both UGT1A1*28 and *6 (double-variant-type of UGT1A1 polymorphism, UGT1A1-DV). FOLFIRINOX is one of the standard treatments for metastatic pancreatic cancer (PC). The optimal dose of irinotecan as a component of the FOLFIRINOX has not been established yet for patients with UGT1A1-DV.

Patients and methods

Advanced PC patients with UGT1A1-DV who had received at least one cycle of FOLFIRINOX from December 2013 to March 2016 were collected retrospectively conducted at multicenter in Japan. We evaluated the patient characteristics, efficacy and safety of FOLFIRINOX and investigate the optimal initial dose of irinotecan in Japanese advanced PC patients with UGT1A1-DV.

Results

A total of 31 patients were enrolled. Grade 4 neutropenia was seen more frequently (67%; 4/6) in patients who had received irinotecan at an initial dose of  ≥ 150 mg/m² than in those who had received the drug at an initial dose of  ≤ 120 mg/m² (20%; 5/24). The response rate (RR) and progression-free survival (PFS) in patients given irinotecan of  ≤ 120 mg/m² were 21.4% and 8.1 months, respectively, which were consistent with previous report for patients without UGT1A1-DV.

Conclusion

Based on our findings, we recommend that in Japanese advanced PC patients with UGT1A1- DV treated with FOLFIRINOX, irinotecan be administered at an initial dose of  ≤ 120 mg/m².

Implementation of pharmacogenomic testing in oncology care (PhOCus): study protocol of a pragmatic, randomized clinical trial

BACKGROUND

Many cancer patients who receive chemotherapy experience adverse drug effects. Pharmacogenomics (PGx) has promise to personalize chemotherapy drug dosing to maximize efficacy and safety. Fluoropyrimidines and irinotecan have well-known germline PGx associations. At our institution, we have delivered PGx clinical decision support (CDS) based on preemptively obtained genotyping results for a large number of non-oncology medications since 2012, but have not previously evaluated the utility of this strategy for patients initiating anti-cancer regimens. We hypothesize that providing oncologists with preemptive germline PGx information along with CDS will enable individualized dosing decisions and result in improved patient outcomes.

METHODS

Patients with oncologic malignancies for whom fluoropyrimidine and/or irinotecan-inclusive therapy is being planned will be enrolled and randomly assigned to PGx and control arms. Patients will be genotyped in a clinical laboratory across panels that include actionable variants in UGT1A1 and DPYD. For PGx arm patients, treating providers will be given access to the patient-specific PGx results with CDS prior to treatment initiation. In the control arm, genotyping will be deferred, and dosing will occur as per usual care. Co-primary endpoints are dose intensity deviation rate (the proportion of patients receiving dose modifications during the first treatment cycle), and grade ⩾3 treatment-related toxicities throughout the treatment course. Additional study endpoints will include cumulative drug dose intensity, progression-free survival, dosing of additional PGx supportive medications, and patient-reported quality of life and understanding of PGx.

DISCUSSION

Providing a platform of integrated germline PGx information may promote personalized chemotherapy dosing decisions and establish a new model of care to optimize oncology treatment planning.

FOLFIRINOX as second-line chemotherapy for advanced pancreatic cancer: A subset analysis of data from a nationwide multicenter observational study in Japan

BACKGROUND

Data on FOLFIRINOX as a second-line chemotherapy for advanced pancreatic cancer are limited. In the JASPAC06 study-a nationwide, multicenter, observational study-FOLFIRINOX for patients with unresectable or recurrent pancreatic cancer as any line of treatment showed favorable efficacy and safety in Japanese clinical practice.

METHODS

We performed exploratory analyses of patients with unresectable or recurrent pancreatic cancer who received FOLFIRINOX as the second-line chemotherapy in Japanese clinical settings.

RESULTS

Of the 399 evaluable patients, 44 were eligible for inclusion in the analysis. The patients' characteristics were as follows: median age, 62 years; men, 26 (59%); Eastern Cooperative Oncology Group-Performance status 0/1, 30 (68%)/14 (32%); disease status, recurrent/local/metastatic: 4 (9%)/8 (18%)/32 (73%). The initial dose was reduced in 28 (64%) patients. The median time to treatment failure and number of cycles were 4.5 (range, 0.2-19.1) months and 6 cycles (range, 1-13 or more), respectively. The major grade 3/4 adverse events were neutropenia in 29 (66%), leucopenia in 17 (39%), anorexia in 7 (16%), febrile neutropenia in 5 (11%), and anemia in 5 (11%) patients. The median overall survival, progression-free survival, and 1-year survival rates were 10.3 (95% confidence interval [CI], 7.2-13.3), 4.1 (95% CI, 2.6-5.5) months, and 30%, respectively.

CONCLUSION

Our findings suggest that FOLFIRINOX as a second-line chemotherapy for advanced pancreatic cancer was effective in patients with a good performance status. It displayed toxicity similar to that observed with its use as a first-line treatment.

Main contribution of UGT1A1 and CYP2C9 in the metabolism of UR-1102, a novel agent for the treatment of gout

UR-1102, a novel uricosuric agent for treating gout, has been confirmed to exhibit a pharmacological effect in patients. We clarified its metabolic pathway, estimated the contribution of each metabolic enzyme, and assessed the impact of genetic polymorphisms using human in vitro materials. Glucuronide, sulfate and oxidative metabolites of UR-1102 were detected in human hepatocytes. The intrinsic clearance by glucuronidation or oxidation in human liver microsomes was comparable, but sulfation in the cytosol was much lower, indicating that the rank order of contribution was glucuronidation ≥ oxidation > sulfation. Recombinant UGT1A1 and UGT1A3 showed high glucuronidation of UR-1102. We took advantage of a difference in the inhibitory sensitivity of atazanavir to the UGT isoforms and estimated the fraction metabolised (fm) with UGT1A1 to be 70%. Studies using recombinant CYPs and CYP isoform-specific inhibitors showed that oxidation was mediated exclusively by CYP2C9. The effect of UGT1A1 and CYP2C9 inhibitors on UR-1102 metabolism in hepatocytes did not differ markedly between the wild type and variants.

Population Pharmacokinetic Model-Based Evaluation of Circadian Variations in Plasma 5-Fluorouracil Concentrations During Long-Term Infusion in Rats: A Comparison With Oral Anticancer Prodrugs

Circadian fluctuations in the plasma concentration of 5-fluorouracil impede the accurate estimation of target therapeutic concentrations in the long-term infusion or oral 5-fluorouracil-based prodrug regimen. We evaluated the circadian patterns of plasma 5-fluorouracil concentrations in rats using population pharmacokinetic model. Rats were divided into 2 groups, and a continuous infusion (50 mg/m²/h) for 48 h was initiated with or without a bolus injection of 60 mg/kg 5-fluorouracil. In the group not administered a loading dose, significant circadian variation of plasma 5-fluorouracil concentration was observed. In contrast, in the loading dose group, this circadian variation disappeared. Additionally, decreased hepatic dihydropyrimidine dehydrogenase activity was observed. Population model analysis revealed that the concentrations of 5-fluorouracil followed a 24-h cosine circadian curve, representing an overall 1.8-fold increase from a nadir to a peak, with a relative amplitude (% of mesor) of 28%. The circadian 5-fluorouracil clearance pattern in the infusion-regimen was consistent with previously reported pattern for capecitabine and uracil-tegafur. In the recently modified regimen omitting the bolus injection of 5-fluorouracil, the circadian variations should be considered for blood sampling time points in therapeutic drug monitoring. The chronomodulated chemotherapy using oral prodrug administration could be established based on accumulating evidence in the infusion-regimen.

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

BACKGROUND

FOLFIRINOX 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.

AIM

To investigate the potential clinical value of FOLFOXIRI in patients with aPDAC in routine clinical practice.

METHODS

Analyses 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.

RESULTS

Median 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.

CONCLUSION

FOLFOXIRI 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.

Modified FOLFIRINOX for resected pancreatic cancer: Opportunities and challenges

Pancreatic cancer is one of the leading causes of cancer death worldwide. Adjuvant chemotherapy has been developed based on the experiences made with palliative chemotherapy, and advocated to improve long-term survival of patients with this disease. However, the optimal chemotherapeutic regimen remains controversial. Recently, Conroy et al demonstrated the impressive benefits of modified FOLFIRINOX over gemcitabine alone in the multicenter Partenariat de Recherche en Oncologie Digestive 24 (PRODIGE-24) trial. The remarkable results mark a new milestone in treating resectable pancreatic cancer and have now changed the standard of care for this patient population. In this commentary, we discuss an issue of difference of tumor grade between the PRODIGE-24 trial and previous phase III trials. We also discuss potential biomarkers predicting therapeutic response to modified FOLFIRINOX. Finally, we summarize several ongoing clinical trials of replacing part of the FOLFIRINOX regimen with Xeloda/S-1/nanoliposomal irinotecan for pancreatic cancer.

Impact of UGT1A1 genetic polymorphism on toxicity in unresectable pancreatic cancer patients undergoing FOLFIRINOX

Studies have indicated an association between UDP‐glucuronosyltransferase‐1A1 (UGT1A1) genetic polymorphisms and irinotecan‐induced toxicity. We undertook this study to investigate the association between UGT1A1 genetic polymorphisms and toxicity in patients treated with the FOLFIRINOX (comprising oxaliplatin, irinotecan, fluorouracil, and leucovorin) chemotherapy regimen in the JASPAC 06 study. Patients screened for UGT1A1*6 and UGT1A1*28, and treated with either the original FOLFIRINOX (oxaliplatin 85 mg/m², irinotecan 180 mg/m², leucovorin 200 mg/m², bolus 5‐fluorouracil [5‐FU] 400 mg/m², and continuous 5‐FU 2400 mg/m²) or a modified FOLFIRINOX (oxaliplatin 85 mg/m², irinotecan 150 mg/m², leucovorin 200 mg/m², and continuous 5‐FU 2400 mg/m²) as first‐line chemotherapy were included. Of 199 patients eligible for this analysis, 79 patients were treated with the original FOLFIRINOX regimen and 120 patients were treated with the modified FOLFIRINOX regimen. In the original FOLFIRINOX group, 54 were UGT1A1 WT, and 25 were UGT1A1 heterozygous type (−/*6, 12 patients; −/*28, 13 patients). In the modified FOLFIRINOX group, 64 were UGT1A1 WT and 56 were UGT1A1 heterozygous type (−/*6, 33 patients; −/*28, 23 patients).

In the original FOLFIRINOX group, the incidence of diarrhea was significantly higher among patients with UGT1A1 heterozygous type than among those with UGT1A1 WT and the incidence of leukopenia and diarrhea was significantly higher among patients with UGT1A1 −/*6 than among those with UGT1A1 −/*28. Patients with UGT1A1 heterozygous type, especially those with UGT1A1 −/*6, tended to show a higher incidence rate of severe adverse events, but this was not statistically significant. However, for patients who received the modified FOLFIRINOX, there was no difference in the frequency of adverse events due to UGT1A1 status. In conclusion, patients with heterozygous UGT1A1 polymorphisms treated with the original FOLFIRINOX regimen experienced severe toxicity more frequently than patients with WT UGT1A1.