UGT1A1 genotype-guided irinotecan dosing during neoadjuvant chemoradiotherapy for locally advanced rectal cancer: A prospective analysis of SN-38 concentration.

Irinotecan plays a crucial role in the neoadjuvant chemoradiotherapy (nCRT) of rectal cancer, but its optimal dosing is still unclear. In this study, we included 101 eligible patients with the UGT1A1*28 genotype of UGT1A1*1*1 (74.3%) and UGT1A1*1*28 (25.7%) and UGT1A1*6 genotypes of GG (63.4%), GA (32.7%), and AA (3.9%). All patients received preoperative radiotherapy (50 Gy/25 fractions) with concurrent irinotecan (UGT1A1*1*1: 80 mg/m2 ; UGT1A1*1*28: 65 mg/m2 ) and capecitabine (CapIri). SN-38 concentrations were measured at 1.5, 24, and 49 h post-administration. Patients were divided into four groups (Q1-Q4) based on the SN-38 concentration. The complete-response (CR) rate was the primary endpoint. The analysis demonstrated that the 49 h SN-38 concentration was relatively optimal for predicting efficacy and toxicity. The Q4 group had a significantly higher CR rate than the Q1 group (p = .019), but also higher rates of adverse events (p = .009). We screened the recommended 49 h SN-38, with a 0.5-1.0 ng/mL concentration range. We also validated the correlation between UGT1A1*6 polymorphism and SN-38 concentration, along with the clinical efficacy of irinotecan. In conclusion, our study identified the relatively optimal timepoint and concentration range for monitoring SN38 concentrations and revealed the clinical significance of UGT1A1*6 and UGT1A1*28 polymorphisms in guiding irinotecan administration, offering meaningful insights for personalised irinotecan dosing.

Clinical outcomes of liposomal irinotecan in patients with advanced pancreatic cancer previously treated with conventional irinotecan: A meta-analysis of real-world evidence.

BACKGROUND: Pivotal clinical trials supported survival benefits of liposomal irinotecan (nal-IRI) plus fluorouracil/leucovorin in patients with pancreatic ductal adenocarcinoma (PDAC) who previously received gemcitabine-based therapy. There are concerns about the benefits of nal-IRI in patients who received FOLFIRINOX (combined fluorouracil, leucovorin, IRI, and oxaliplatin) because of potential cross-resistance to IRI. The objective of this meta-analysis was to characterize the impact of the previous receipt of IRI on the outcomes of nal-IRI regimens in patients with advanced PDAC. METHODS: Real-world studies evaluating the outcomes of nal-IRI in patients who had prior IRI exposure published up to April 2023 were searched using electronic databases. The meta-analysis was conducted using a random effects model to estimate pooled hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Eight studies (n = 1368 patients) were included. The pooled median progression-free survival (PFS) was 2.02 months (95% CI, 1.43-2.57 months), and the median overall survival (OS) was 4.26 months (95% CI, 3.03-5.39 months). Patients with prior IRI exposure had PFS (HR, 1.17; 95% CI, 0.94-1.47; p = .17) and OS (HR, 1.16; 95% CI, 0.95-1.42; p = .16) comparable to patients without prior IRI exposure. Likewise, patients who had progressive disease on conventional IRI had PFS (HR, 1.50; 95% CI, 0.73-3.08; p = .24) and OS (HR, 1.70; 95% CI, 0.68-4.27; p = .26) with nal-IRI comparable to patients who had no progressive disease. CONCLUSIONS: Prior IRI exposure does not affect the survival outcomes of nal-IRI regimens in patients who have advanced PDAC. The selection of later lines of chemotherapy regimens should be based on the differential safety profile, patient status, the cost of treatment, and health-related quality of life.

A phase II trial of UGT1A1 genotype-guided FOLFIRI plus bevacizumab as first-line therapy for advanced, unresectable colorectal cancer.

BACKGROUND: FOLFIRI is a standard regimen for metastatic colorectal cancer (mCRC). We hypothesized that a pharmacogenomic-directed strategy where more efficient irinotecan metabolizers (UGT1A1 *1/*1 homozygotes and *1/*28 heterozygotes) receive higher-than-standard irinotecan doses would improve progression-free survival (PFS) compared to non-genotype selected historical controls with acceptable toxicity. METHODS: In this phase II multicenter study irinotecan dosing in first-line FOLFIRI and bevacizumab for mCRC was based on UGT1A1 genotype with *1/*1, *1/*28, and *28/*28 patients receiving 310 mg/m2, 260 mg/m2, and 180 mg/m2, respectively. Primary endpoint was PFS. Secondary endpoints were investigator and patient-reported adverse events, and estimation of overall survival (OS). RESULTS: One-hundred patients were enrolled with 91 evaluable for PFS and 83 evaluable for best response. Median PFS was 12.5 months (90% CI 10.9, 15.4), shorter than the anticipated alternative hypothesis of 14 months. PFS by genotype was 12.5 months (90% CI 10.9, 17.4) for *1/*1, 14.6 months (90% CI 11.8, 17.5) for *1/*28, and 6 months (90% CI 2.3, 7.7) for *28/28, respectively. OS was 24.5 months (90% CI 19.1, 30.7) and by genotype was 26.5 (90% CI 19.1, 32.9), 25.9 (90% CI 17.6, 37.7), and 13.4 (90% CI 2.3, 20.5) months for *1/*1, *1/*28, and *28/*28, respectively. G3/4 toxicity was similar between all subgroups, including diarrhea and neutropenia. CONCLUSIONS: A pharmacogenomic-directed irinotecan strategy improved PFS in the *1/*1 and *1/*28 genotypes with higher rates of neutropenia and similar rates of diarrhea compared to expected with standard FOLFIRI dosing. However, improvements in response rate and PFS were modest. This strategy should not change standard practice for mCRC patients in the first-line setting.

SN-38, an active metabolite of irinotecan, inhibits transcription of nuclear factor erythroid 2-related factor 2 and enhances drug sensitivity of colorectal cancer cells.

Nuclear factor erythroid 2-related factor 2 (Nrf2) significantly contributes to drug resistance of cancer cells, and Nrf2 inhibitors have been vigorously pursued. Repurposing of existing drugs, especially anticancer drugs, is a straightforward and promising strategy to find clinically available Nrf2 inhibitors and effective drug combinations. Topoisomerase inhibitors SN-38 (an active metabolite of irinotecan), topotecan, mitoxantrone, and epirubicin were found to significantly suppress Nrf2 transcriptional activity in cancer cells. SN-38, the most potent one among them, significantly inhibited the transcription of Nrf2, as indicated by decreased mRNA level and binding of RNA polymerase II to NFE2L2 gene, while no impact on Nrf2 protein or mRNA degradation was observed. SN-38 synergized with Nrf2-sensitive anticancer drugs such as mitomycin C in killing colorectal cancer cells, and irinotecan and mitomycin C synergistically inhibited the growth of SW480 xenografts in nude mice. Our study identified SN-38 and three other topoisomerase inhibitors as Nrf2 inhibitors, revealed the Nrf2-inhibitory mechanism of SN-38, and indicate that clinically feasible drug combinations could be designed based on their interactions with Nrf2 signaling.

Bifidobacterium longum SX-1326 ameliorates gastrointestinal toxicity after irinotecan chemotherapy via modulating the P53 signaling pathway and brain-gut axis.

BACKGROUND: Colorectal cancer (CRC) is a prevalent malignant malignancy affecting the gastrointestinal tract that is usually treated clinically with chemotherapeutic agents, whereas chemotherapeutic agents can cause severe gastrointestinal toxicity, which brings great pain to patients. Therefore, finding effective adjuvant agents for chemotherapy is crucial. METHODS: In this study, a CRC mouse model was successfully constructed using AOM/DSS, and the treatment was carried out by probiotic Bifidobacterium longum SX-1326 (B. longum SX-1326) in combination with irinotecan. Combining with various techniques of modern biomedical research, such as Hematoxylin and Eosin (H&E), Immunohistochemistry (IHC), Western blotting and 16S rDNA sequencing, we intend to elucidate the effect and mechanism of B. longum SX-1326 in improving the anticancer efficacy and reducing the side effects on the different levels of molecules, animals, and bacteria. RESULTS: Our results showed that B. longum SX-1326 enhanced the expression of Cleaved Caspase-3 (M vs. U = p < 0.01) and down-regulated the expression level of B-cell lymphoma-2 (Bcl-2) through up-regulation of the p53 signaling pathway in CRC mice, which resulted in an adjuvant effect on the treatment of CRC with irinotecan. Moreover, B. longum SX-1326 was also able to regulate the gut-brain-axis (GBA) by restoring damaged enterochromaffin cells, reducing the release of 5-hydroxytryptamine (5-HT) in brain tissue (I vs. U = 89.26 vs. 75.03, p < 0.05), and further alleviating the adverse effects of nausea and vomiting. In addition, B. longum SX-1326 reversed dysbiosis in CRC model mice by increasing the levels of Dehalobacterium, Ruminnococcus, and Mucispirillum. And further alleviated colorectal inflammation by downregulating the TLR4/MyD88/NF-κB signaling pathway. CONCLUSIONS: In conclusion, our work reveals that B. longum SX-1326 has a favorable effect in adjuvant irinotecan for CRC and amelioration of post-chemotherapy side effects, and also provides the theoretical basis and data for finding a safe and efficient chemotherapeutic adjuvant.

Liposomal irinotecan (HR070803) in combination with 5-fluorouracil and leucovorin in patients with advanced solid tumors: a phase 1b dose-escalation and expansion study.

This phase 1b study aimed to evaluate the dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetics, and preliminary efficacy of HR070803, a novel nanoliposomal formulation of irinotecan, in combination with 5-fluorouracil and leucovorin in patients with pretreated advanced solid tumors. This study consisted of dose-escalation and expansion stages. Dose escalation was performed with a traditional 3 + 3 design; patients received intravenous infusion of HR070803 from 60 to 80 mg/m2, followed by leucovorin (200 mg/m2) and 5-fluorouracil (2000 mg/m2) every 2 weeks. In the expansion stage, patients received treatments at selected tolerable dose. Fifteen patients received treatments at 60 mg/m2 (n = 12) and 80 mg/m2 (n = 3). DLTs occurred in 2 patients at 80 mg/m2 (grade 2 neutropenia that resulted in a dose delay of ≥ 7 days, n = 1; grade 3 febrile neutropenia, n = 1). The MTD was determined to be 60 mg/m2. The most frequent HR070803related adverse events included anorexia, leukopenia, neutropenia, nausea, fatigue, and diarrhea. SN-38, the active metabolite of irinotecan, exhibited lower maximum plasma concentrations and a prolonged terminal half-life when irinotecan was administered via nanoliposome compared to conventional injection. Overall, 4 patients achieved a partial response (confirmed, n = 2), and 9 had stable disease. The MTD of HR070803 was 60 mg/m2 when infused with 5-fluorouracil and leucovorin. Nanoliposomal encapsulation modified the pharmacokinetics of irinotecan and SN-38. HR070803 with 5-fluorouracil and leucovorin demonstrated a manageable safety profile and promising antitumor efficacy in advanced solid tumors. TRIAL REGISTRATION: Clinicaltrials.gov, NCT05086848. Retrospectively registered on Oct. 12, 2021.

Phase I study of trifluridine/tipiracil (TAS-102) plus irinotecan in combination with bevacizumab as a second-line therapy for patients with metastatic colorectal cancer.

PURPOSE: This phase I trial is to determine the recommended dose of the TAS-102, irinotecan plus bevacizumab regimen and assess its safety and efficacy in patients with metastatic colorectal cancer refractory to fluoropyrimidine and oxaliplatin treatment. METHODS: A 3 + 3 designed dose escalation was performed. Patients were administered TAS-102 (30-35 mg/m2 twice daily on days 1-5) and irinotecan (150-165 mg/m2 on day 1) combined with a fixed dose of bevacizumab (5 mg/kg on day 1) every two weeks. The primary endpoint was the determination of the recommended phase II dose. RESULTS: Eighteen patients were enrolled: 6 at the Level 1 (TAS-102 30 mg/m2 twice daily, irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg), six at the Level 2 (TAS-102 35 mg/m2 twice daily, irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg), and six at the Level 3 (TAS-102 30 mg/m2 twice daily, irinotecan 165 mg/m2 plus bevacizumab 5 mg/kg). Five dose-limiting toxicities occurred: one observed at Level 1 (thrombocytopenia), two at Level 2 (neutropenia and diarrhea), and two at Level 3 (fatigue and neutropenia). The RP2D was established as TAS-102 30 mg/m2 twice daily and irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg. The most frequent grade 3/4 treatment-related adverse events were neutropenia (33.3%), diarrhea (16.7%), and thrombocytopenia (11.1%). No treatment-related death occurred. Two patients (11.1%) experienced partial responses and 14 (77.8%) had stable disease. CONCLUSION: The regimen of TAS-102, irinotecan, and bevacizumab is tolerable with antitumor activity for metastatic colorectal cancer patients refractory to first-line fluoropyrimidines and oxaliplatin treatment.

Real-world outcomes of third-line immune checkpoint inhibitors versus irinotecan-based chemotherapy in patients with advanced gastric cancer: a Korean, multicenter study (KCSG ST22-06).

BACKGROUND: Immune checkpoint inhibitor (ICI) or irinotecan-based chemotherapy is frequently used after failure of second-line paclitaxel plus ramucirumab treatment for patients with locally advanced unresectable or metastatic advanced gastric cancer (AGC). This study aimed to compare the efficacy between ICI and irinotecan-based chemotherapy as third-line treatment in patients with AGC. METHODS: We retrospectively reviewed patients with AGC, whose third-line treatment started between July 2019 and June 2021 at 17 institutions in Korea. The ICI group included patients who received nivolumab or pembrolizumab, and the irinotecan-based chemotherapy group included patients who received irinotecan or FOLFIRI (5-fluorouracil, leucovorin and irinotecan). RESULTS: A total of 363 patients [n = 129 (ICI) and n = 234 (irinotecan-based chemotherapy)] were analyzed. The median progression-free survival was 2.3 and 2.9 months in ICI and irinotecan-based chemotherapy groups, respectively (p = 0.802). The median overall survival (OS) was 5.5 and 6.0 months in ICI and irinotecan-based chemotherapy groups, respectively (p = 0.786). For all patients included in this study, multivariable analysis showed that weight loss, peritoneal metastasis, low serum sodium or albumin, and short duration of second-line treatment were associated with inferior OS (p < 0.05). ICI showed significantly longer OS than irinotecan-based chemotherapy in patients without peritoneal metastasis. Whereas ICI showed significantly shorter OS in patients without PD-L1 expression than irinotecan-based chemotherapy. CONCLUSIONS: No significant difference in survival outcome was observed between ICI and irinotecan-based chemotherapy as third-line treatment for AGC patients. ICI might be preferred for patients without peritoneal metastasis and irinotecan-based chemotherapy for patients with tumors without PD-L1 expression. TRIAL REGISTRATION: This study was registered in the Clinical Trial Registry of Korea ( https://cris.nih.go.kr : KCT 0007732).

Survival outcome of different treatment sequences in patients with locally advanced and metastatic pancreatic cancer.

BACKGROUND: Despite some therapeutic advances, improvement in survival rates of unresectable and/or metastatic pancreatic ductal adenocarcinoma (PDAC) has been minimal over recent decade. We aimed to evaluate the impact of different treatment sequences on clinical outcomes of advanced PDAC at our academic institution. METHODS: In this single institution retrospective analysis, we assessed characteristics and survival rates of unresectable and/or metastatic pancreatic PDAC patients who started a systemic treatment between 01/2015 and 12/2021. Survival analyses were performed by Kaplan-Meier and Cox proportional hazards model. RESULTS: The number of 285 patients received at least two lines of treatment, but only 137 patients were suitable for third-line treatment. Subgroup analysis showed that thirty-seven patients received A line (gemcitabine/nab-paclitaxel or nab-paclitaxel combined therapy to FOLFIRINOX) therapy, 37 patients received B line (nab-paclitaxel combined therapy to gemcitabine combined therapy to FOLFIRINOX) therapy, 21 patients received C line (nab-paclitaxel combined therapy to gemcitabine combined therapy to oxaliplatin or irinotecan combined therapy) therapy. Survival rates for different treatment lines were significantly different and median overall survival (OS) was 14.00, 18.00, and 14.00 months, respectively (p<0.05). CONCLUSION: Our study provides real-world evidence for the effectiveness of different treatment sequences and underscores the treatment sequences on survival outcome when considering the entire management in advanced PDAC.

An evaluation model of hepatic steatosis based on CT value and serum uric acid/HDL cholesterol ratio can predict intrahepatic recurrence of colorectal cancer liver metastasis.

BACKGROUND: Intrahepatic recurrence is one of the main causes of treatment failure in patients with colorectal cancer liver metastasis (CRLM). Hepatic steatosis was reported to provide fertile soil for metastasis. The effect of irinotecan-inducted hepatic steatosis on the progression of liver metastasis remains to be verified. Therefore, we aim to clarify the effect of hepatic steatosis on postoperative intrahepatic recurrence in CRLM and whether it is relevant to irinotecan-based chemotherapy. METHODS: Data for a total of 284 patients undergoing curative surgical treatment for CRLMs were retrospectively reviewed between March 2007 and June 2018. Hepatic steatosis score (HSS) was established by combining Liver to Spleen CT ratio (LSR) and Uric acid to HDL-cholesterol ratio (UHR) to detect the presence of hepatic steatosis. RESULTS: The evaluation model is consistent with pathological results and has high prediction ability and clinical application value. Patients with HSS high risk (HSS-HR) had significantly worse prognosis than those with HSS low risk (HSS-LR) (3-year intrahepatic RFS: 42.7% vs. 29.4%, P = 0.003; 5-year OS: 45.7% vs. 26.5%, P = 0.002). Univariate and multivariate analysis confirmed its essential role in the prediction of intrahepatic RFS. Besides, patients treated with preoperative irinotecan chemotherapy were more likely to end up with HSS-HR than those with non-irinotecan chemotherapy (63.3% vs. 21.8%, P < 0.001). Furthermore, irinotecan chemotherapy is relevant to worse prognosis in baseline HSS-HR patients. CONCLUSION: In summary, patients with HSS-HR had significantly worse 5-year OS and 3-year intrahepatic RFS. Irinotecan chemotherapy is more likely to lead to HSS-HR and pre-existing hepatic steatosis may be a worse prognostic factor limiting patients underwent IRI-based chemotherapy.

Liposomal irinotecan plus fluorouracil/leucovorin in older patients with advanced pancreatic cancer: a single-center retrospective study.

BACKGROUND: The global phase 3 NAPOLI -1 trial of patients with pancreatic ductal adenocarcinoma (PDAC) demonstrated an overall survival (OS) benefit from using liposomal irinotecan and 5-fluorouracil/leucovorin (nal-IRI + 5-FU/LV) after treatment with gemcitabine (GEM) compared to 5-FU/LV alone. However, the efficacy and safety of this regimen in older patients are not well studied. METHODS: We conducted a single-center retrospective study to compare the therapeutic efficacy of nal-IRI + 5-FU/LV between older and younger patients with cutoff ages of 70 and 75 years, respectively. We included patients with a prior history of one or more GEM-based regimens for locally advanced or metastatic PDAC and were treated with nal-IRI + 5-FU/LV. RESULTS: Of the 115 patients, 54 (47.0%) and 24 (20.9%) were aged ≥ 70 and ≥ 75 years, respectively. The median OS and progression-free survival (PFS) of the entire cohort were 8.5 and 3.6 months, respectively. No significant differences were observed in OS and PFS hazard ratios using age cutoffs of 70 (P = 0.90 and 0.99, respectively) and 75 (P = 0.90 and 0.76, respectively) years. Additionally, no significant differences were found in the incidence of treatment-related adverse events (trAEs) between patients aged ≥ 70 and < 70 years or those aged ≥ 75 and < 75 years. Other than hematological toxicity, no trAEs higher than Grade 4 were observed in either age group. CONCLUSION: The efficacy and safety of nal-IRI + 5-FU/LV for patients with PDAC are not significantly different for those aged ≥ 70 years compared to younger patients.

Pharmacogenetics testing (DPYD and UGT1A1) for fluoropyrimidine and irinotecan in routine clinical care: Perspectives of medical oncologists and oncology pharmacists.

BACKGROUND: Despite robust evidence and international guidelines, to support routine pharmacogenetic (PGx) testing, integration in practice has been limited. This study explored clinicians' views and experiences of pre-treatment DPYD and UGT1A1 gene testing and barriers to and enablers of routine clinical implementation. METHODS: A study-specific 17-question survey was emailed (01 February-12 April 2022) to clinicians from the Medical Oncology Group of Australia (MOGA), the Clinical Oncology Society of Australia (COSA) and International Society of Oncology Pharmacy Practitioners (ISOPP). Data were analysed and reported using descriptive statistics. RESULTS: Responses were collected from 156 clinicians (78% medical oncologists, 22% pharmacists). Median response rate of 8% (ranged from 6% to 24%) across all organisations. Only 21% routinely test for DPYD and 1% for UGT1A1. For patients undergoing curative/palliative intent treatments, clinicians reported intent to implement genotype-guided dosing by reducing FP dose for DPYD intermediate metabolisers (79%/94%), avoiding FP for DPYD poor metabolisers (68%/90%), and reducing irinotecan dose for UGT1A1 poor metabolisers (84%, palliative setting only). Barriers to implementation included: lack of financial reimbursements (82%) and perceived lengthy test turnaround time (76%). Most Clinicians identified a dedicated program coordinator, i.e., PGx pharmacist (74%) and availability of resources for education/training (74%) as enablers to implementation. CONCLUSION: PGx testing is not routinely practised despite robust evidence for its impact on clinical decision making in curative and palliative settings. Research data, education and implementation studies may overcome clinicians' hesitancy to follow guidelines, especially for curative intent treatments, and may overcome other identified barriers to routine clinical implementation.

British Oncology Pharmacy Association Delphi consensus guidelines: Co-infusion of trometamol-containing calcium folinate (Leucovorin) with systemic anti-cancer treatments.

Drug stability and compatibility are critical factors influencing the cost and logistics of treatment delivery, therapeutic effectiveness, and patient safety. This is particularly significant in the realm of cancer chemotherapeutics, where stability and compatibility studies play a vital role in ensuring rational and safe medicine administration. Oxaliplatin, fluorouracil, and irinotecan, commonly used in various combinations for gastrointestinal cancers, are complemented by co-administration of folinic acid in certain protocols. Notably, some folinic acid preparations include trometamol as an excipient, potentially impacting the stability of the chemotherapeutic agents if infused concomitantly. This study seeks to establish guidelines for oncology multidisciplinary teams, addressing potential risks associated with the combination of trometamol-containing folinic acid and chemotherapeutics. To achieve this, a quantitative questionnaire was distributed to members of the British Oncology Pharmacy Association (BOPA) and non-BOPA members through an online survey. Nineteen healthcare professionals with oncology experience, comprising 18 pharmacists and one nurse, completed the questionnaires. Each participant rated the validity and clarity of statements on a 5-point scale. The Delphi process concluded after the fourth round, consolidating the findings and recommendations from the multidisciplinary team. Twelve recommendations for safe practice have been made.

Phenethyl isothiocyanate and irinotecan synergistically induce cell apoptosis in colon cancer HCT 116 cells in vitro.

Irinotecan (IRI), an anticancer drug to treat colon cancer patients, causes cytotoxic effects on normal cells. Phenethyl isothiocyanate (PEITC), rich in common cruciferous plants, has anticancer activities (induction of cell apoptosis) in many human cancer cells, including colon cancer cells. However, the anticancer effects of IRI combined with PEITC on human colon cancer cells in vitro were unavailable. Herein, the aim of this study is to focus on the apoptotic effects of the combination of IRI and PEITC on human colon cancer HCT 116 cells in vitro. Propidium iodide (PI) exclusion and Annexin V/PI staining assays showed that IRI combined with PEITC decreased viable cell number and induced higher cell apoptosis than that of IRI or PEITC only in HCT 116 cells. Moreover, combined treatment induced higher levels of reactive oxygen species (ROS) and Ca2+ than that of IRI or PEITC only. Cells pre-treated with N-acetyl-l-cysteine (scavenger of ROS) and then treated with IRI, PEITC, or IRI combined with PEITC showed increased viable cell numbers than that of IRI or PEITC only. IRI combined with PEITC increased higher caspase-3, -8, and -9 activities than that of IRI or PEITC only by flow cytometer assay. IRI combined with PEITC induced higher levels of ER stress-, mitochondria-, and caspase-associated proteins than that of IRI or PEITC treatment only in HCT 116 cells. Based on these observations, PEITC potentiates IRI anticancer activity by promoting cell apoptosis in the human colon HCT 116 cells. Thus, PEITC may be a potential enhancer for IRI in humans as an anticolon cancer drug in the future.

Cytostatic Bacterial Metabolites Interfere with 5-Fluorouracil, Doxorubicin and Paclitaxel Efficiency in 4T1 Breast Cancer Cells.

The microbiome is capable of modulating the bioavailability of chemotherapy drugs, mainly due to metabolizing these agents. Multiple cytostatic bacterial metabolites were recently identified that have cytostatic effects on cancer cells. In this study, we addressed the question of whether a set of cytostatic bacterial metabolites (cadaverine, indolepropionic acid and indoxylsulfate) can interfere with the cytostatic effects of the chemotherapy agents used in the management of breast cancer (doxorubicin, gemcitabine, irinotecan, methotrexate, rucaparib, 5-fluorouracil and paclitaxel). The chemotherapy drugs were applied in a wide concentration range to which a bacterial metabolite was added in a concentration within its serum reference range, and the effects on cell proliferation were assessed. There was no interference between gemcitabine, irinotecan, methotrexate or rucaparib and the bacterial metabolites. Nevertheless, cadaverine and indolepropionic acid modulated the Hill coefficient of the inhibitory curve of doxorubicin and 5-fluorouracil. Changes to the Hill coefficient implicate alterations to the kinetics of the binding of the chemotherapy agents to their targets. These effects have an unpredictable significance from the clinical or pharmacological perspective. Importantly, indolepropionic acid decreased the IC50 value of paclitaxel, which is a potentially advantageous combination.

Innovative Nanoparticulate Strategies in Colon Cancer Treatment: A Paradigm Shift.

As a major public health issue, colorectal cancer causes 9.4% of total cancer-related deaths and comprises 10% of new cancer diagnoses worldwide. In the year 2023, an estimated 153,020 people are expected to receive an identification of colorectal cancer (CRC), resulting in roughly 52,550 fatalities anticipated as a result of this illness. Among those impacted, approximately 19,550 cases and 3750 deaths are projected to occur in individuals under the age of 50. Irinotecan (IRN) is a compound derived from the chemical structure of camptothecin, a compound known for its action in inhibiting DNA topoisomerase I. It is employed in the treatment strategy for CRC therapies. Comprehensive in vivo and in vitro studies have robustly substantiated the anticancer efficacy of these compounds against colon cancer cell lines. Blending irinotecan in conjunction with other therapeutic cancer agents such as oxaliplatin, imiquimod, and 5 fluorouracil enhanced cytotoxicity and improved chemotherapeutic efficacy. Nevertheless, it is linked to certain serious complications and side effects. Utilizing nano-formulated prodrugs within "all-in-one" carrier-free self-assemblies presents an effective method to modify the pharmacokinetics and safety portfolio of cytotoxic chemotherapeutics. This review focuses on elucidating the mechanism of action, exploring synergistic effects, and innovating novel delivery approaches to enhance the therapeutic efficacy of irinotecan.

Optimized rat models better mimic patients with irinotecan-induced severe diarrhea.

Irinotecan-induced severe diarrhea (IISD) not only limits irinotecan's application but also significantly affects patients' quality of life. However, existing animal models often inadequately represent the dynamics of IISD development, progression, and resolution across multiple chemotherapy cycles, yielding non-reproducible and highly variable response with limited clinical translation. Our studies aim to establish a reproducible and validated IISD model that better mimics the pathophysiology progression observed in patients, enhancing translational potential. We investigated the impact of dosing regimens (including different dose, infusion time, and two cycles of irinotecan administration), sex, age, tumor-bearing conditions, and irinotecan formulation on the IISD incidence and severity in mice and rats. Lastly, we investigated above factors' impact on pharmacokinetics of irinotecan, intestinal injury, and carboxylesterase activities. In summary, we successfully established a standard model establishment procedure for an optimized IISD model with highly reproducible severe diarrhea incidence rate (100%) and a low mortality rate (11%) in F344 rats. Additionally, the rats tolerated at least two cycles of irinotecan chemotherapy treatment. In contrast, the mouse model exhibited suboptimal IISD incidence rates (60%) and an extremely high mortality rate (100%). Notably, dosing regimen, age and tumor-bearing conditions of animals emerged as critical factors in IISD model establishment. In conclusion, our rat IISD model proves superior in mimicking pathophysiology progression and characteristics of IISD in patients, which stands as an effective tool for mechanism and efficacy studies in future chemotherapy-induced gut toxicity research.

Patient-derived tumor organoids predict responses to irinotecan-based neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer.

Adding irinotecan to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) increases the pathologic complete response (pCR) rate but brings more toxicities. Robust biomarkers to predict response to irinotecan-based nCRT are extremely necessary for selecting the right patients. Our previous study suggests that patient-derived tumor organoids (PDTOs) sensitivity to chemoradiotherapy matches patient responses. In this study, we investigated whether PDTOs sensitivity to irinotecan can predict complete response (CR) and survival. Eligible patients receiving irinotecan-based nCRT between April 5, 2017 and December 11, 2020 were enrolled in the training cohort (n = 91) for response prediction and survival analysis. Patients receiving nCRT between February 21, 2021 and September 17, 2021 were included in the validation cohort (n = 27). Predictive performances of irinotecan organoid size ratio (OSR) for CR or pCR were evaluated. The irinotecan-sensitive groups had higher response rates compared with the insensitive groups (training cohort: 71.8% vs 24.4%, P < .0001; validation cohort, 81.8% vs 18.8%, P = .002). Moreover, the irinotecan-sensitive group had higher rates of 3-year disease-free survival (DFS: 71.6% vs 55.5%, P = .034) and distant metastasis-free survival (DMFS, 77.9% vs 57.2%, P = .015) than the irinotecan-insensitive group. 5-FU and irradiation sensitivities failed to predict 3-year DFS (5-FU: 65.4% vs 61.9%, P = .643; irradiation: 84.8% vs 57.8%; P = .072). Performances of irinotecan OSR to predict CR or pCR were good in the training cohort (CR: AUC = 0.828; 95% CI = 0.723-0.932; pCR: AUC = 0.864; 95% CI = 0.759-0.961). The validation showed robust predictive ability (CR: AUC = 0.796, 95% CI = 0.5974-0.9952; pCR: AUC = 0.917, 95% CI = 0.7921-1.0000). Irinotecan sensitivity in PDTOs was a predictive and prognostic factor in LARC.

China special issue on gastrointestinal tumors-Cetuximab retreatment plus camrelizumab and liposomal irinotecan in patients with RAS wild-type metastatic colorectal cancer: Cohort B of the phase II CRACK study.

Patients with metastatic colorectal cancer (mCRC) have poor long-term survival. Rechallenge with anti-epidermal growth factor receptor (anti-EGFR) based therapy has shown certain activity as late-line therapy. To further improve clinical outcomes, we evaluated the antitumor efficacy and safety of cetuximab in combination with camrelizumab and liposomal irinotecan in patients with RASwt mCRC pretreated with anti-EGFR-based therapy. Patients with RASwt mCRC who had received at least two prior systemic therapies, including anti-EGFR-based treatment in the metastatic or unresectable disease setting, were enrolled in cohort B. Patients were treated with cetuximab (500 mg/m2 ) and camrelizumab (200 mg) plus liposomal irinotecan (HR070803, 60 mg/m2 ) intravenously once every 2 weeks. The primary endpoint was the objective response rate (ORR) by RECIST v1.1. The secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety. At the data cutoff (23 November 2022), 19 patients were enrolled in the two stages, and 16 were evaluable for efficacy analyses. The ORR was 25% (95% confidence interval [CI]: 10.2%-49.5%), and DCR was 75% (95% CI: 50.5%-89.8%). The median PFS and OS were 6.9 (95% CI: 2.6-11.2) and 15.1 (95% CI: 6.1-24.0) months, respectively. Grade 3 treatment-related adverse events (TRAEs) occurred in 15.8% (3/19) of patients. No grade ≥4 TRAEs were found in the safety population. Our study suggests that anti-EGFR retreatment therapy with cetuximab plus camrelizumab and liposomal irinotecan (HR070803) is a promising late-line treatment option with good antitumor activity and well-tolerated toxicity in RASwt mCRC patients.

Pediatric phase 2 trial of a WEE1 inhibitor, adavosertib (AZD1775), and irinotecan for relapsed neuroblastoma, medulloblastoma, and rhabdomyosarcoma.

BACKGROUND: Inhibition of the WEE1 kinase by adavosertib (AZD1775) potentiates replicative stress from genomic instability or chemotherapy. This study reports the pediatric solid tumor phase 2 results of the ADVL1312 trial combining irinotecan and adavosertib. METHODS: Pediatric patients with recurrent neuroblastoma (part B), medulloblastoma/central nervous system embryonal tumors (part C), or rhabdomyosarcoma (part D) were treated with irinotecan and adavosertib orally for 5 days every 21 days. The combination was considered effective if there were at least three of 20 responses in parts B and D or six of 19 responses in part C. Tumor tissue was analyzed for alternative lengthening of telomeres and ATRX. Patient's prior tumor genomic analyses were provided. RESULTS: The 20 patients with neuroblastoma (part B) had a median of three prior regimens and 95% had a history of prior irinotecan. There were three objective responses (9, 11, and 18 cycles) meeting the protocol defined efficacy end point. Two of the three patients with objective responses had tumors with alternative lengthening of telomeres. One patient with pineoblastoma had a partial response (11 cycles), but parts C and D did not meet the protocol defined efficacy end point. The combination was well tolerated and there were no dose limiting toxicities at cycle 1 or beyond in any parts of ADVL1312 at the recommended phase 2 dose. CONCLUSION: This is first phase 2 clinical trial of adavosertib in pediatrics and the first with irinotecan. The combination may be of sufficient activity to consider further study of adavosertib in neuroblastoma.