Dosage Adjustment of Irinotecan in Patients with UGT1A1 Polymorphisms: A Review of Current Literature

Risk Factors for Adverse Events of Nanoliposomal Irinotecan Plus 5-Fluorouracil and L-leucovorin

Background/Aim

The regimen with nanoliposomal irinotecan plus 5-fluorouracil and L-leucovorin (nal-IRI/FL) is used for metastatic pancreatic cancer. A clinical study has indicated that the uridine diphosphate-glucuronosyltransferase (UGT) 1A1 polymorphism is associated with neutropenia during nal-IRI/FL treatment; however, no studies have reported risk factors for the occurrence of adverse events in the clinical setting. This study aimed to explore the risk factors for adverse events of nal-IRI/FL.

Patients and Methods

This study included patients with metastatic pancreatic cancer who started nal-IRI/FL treatment. Patient information, including laboratory data before nal-IRI/FL initiation and adverse events during nal-IRI/FL treatment, was retrospectively obtained from medical records.

Results

This study consisted of 36 patients, including 16, 16, and 4 with UGT1A1*6 or *28 wild-type (-/-), heterozygous (+/-), and homozygous (+/+), respectively. Patients with UGT1A1*6 or *28 (+/+) exhibited significantly lower nadir counts of white blood cells (p=0.033) and neutrophils (p=0.043). Multiple regression analyses revealed that the decreased white blood cell count was significantly associated with the genotype of UGT1A1*6 or *28 (+/+) (p=0.009), high aspartate aminotransferase (AST) value before the therapy (p=0.019), and pancreatic head cancer (p=0.030). Also, the decreased neutrophil count was significantly related to the genotype of UGT1A1*6 or *28 (+/+) (p=0.017).

Conclusion

Patients with UGT1A1*6 or *28 (+/+) should be especially concerned about neutropenia and leukopenia during nal-IRI/FL treatment. Additionally, high AST value and pancreatic head cancer may be risk factors for leukopenia during nal-IRI/FL treatment.

Protective Effects of Arbutus unedo L. Honey in the Alleviation of Irinotecan-Induced Cytogenetic Damage in Human Lymphocytes-An In Vitro Study

Strawberry tree (Arbutus unedo L.) honey (STH) has been used since ancient times as a folk medicine remedy, especially in certain Mediterranean countries. This honey, rich in phenolic content, is well recognized for its antioxidant, anti-inflammatory, and antimicrobial activities, and is used for the treatment of skin lesions as well as gastrointestinal and respiratory disorders. This study investigated whether STH alleviates genome damage in human peripheral blood lymphocytes produced by the cytotoxic drug irinotecan. The phenolic profile of STH was previously estimated by ultra-high-performance liquid chromatography coupled to a linear ion trap-Orbitrap hybrid mass spectrometer. The effects of STH were evaluated at three concentrations (1×, 5×, and 10×), based on the daily consumption of the honey by an adult person. After 2 h of in vitro exposure, standard lymphocyte cultures for the analysis of chromosome aberrations and the cytokinesis-block micronucleus cytome assay were established. Our results demonstrate that STH offered remarkable geno- and cytoprotection when administered with irinotecan. These findings are relevant for drawing preliminary conclusions regarding the in vitro safety of the tested honey. However, further studies are needed with the application of more complex experimental models.

Temporal offset association between the number of irinotecan-related adverse reactions and pharmacogenomic studies: A cross-correlation analysis

Objectives

Studies have proved that UGT1A1 (*6, *28 and *93) gene polymorphism was closely related to the side effects of irinotecan. This study intends to perform a correlation analysis on the relationship between pharmacogenomic studies and ADRs based on time series.

Methods

The ADRs related to irinotecan were derived through the FAERS; searched all pharmacogenomic studies in PubMed and Web of Science; then analyzed the sequence of correlation coefficients between total ADRs, fatal ADRs and pharmacogenomic studies under different time offset.

Results

There is a positive correlation between the number of total ADRs and pharmacogenomic studies, of which the maximum correlation coefficient was 0.78 (95 % CI: 0.58-0.90), with a lag of 1 year. There is also a positive correlation between the number of fatal ADRs and pharmacogenomic studies, with the maximum correlation coefficient of 0.87 (95 % CI: 0.73-0.94) and a offset of - 4 years.

Conclusion

It was found that both the total ADRs and fatal ADRs were significantly positively correlated with change trend of published pharmacogenomic literatures, which confirmed the role of pharmacogenomic research in promoting the safe use of irinotecan, and have a faster response time in reducing fatal ADRs during clinical application.

Next-Generation Personalized Medicine: Implementation of Variability Patterns for Overcoming Drug Resistance in Chronic Diseases

Chronic diseases are a significant healthcare problem. Partial or complete non-responsiveness to chronic therapies is a significant obstacle to maintaining the long-term effect of drugs in these patients. A high degree of intra- and inter-patient variability defines pharmacodynamics, drug metabolism, and medication response. This variability is associated with partial or complete loss of drug effectiveness. Regular drug dosing schedules do not comply with physiological variability and contribute to resistance to chronic therapies. In this review, we describe a three-phase platform for overcoming drug resistance: introducing irregularity for improving drug response; establishing a deep learning, closed-loop algorithm for generating a personalized pattern of irregularity for overcoming drug resistance; and upscaling the algorithm by implementing quantified personal variability patterns along with other individualized genetic and proteomic-based ways. The closed-loop, dynamic, subject-tailored variability-based machinery can improve the efficacy of existing therapies in patients with chronic diseases.

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.

Pharmacogenomics in Cytotoxic Chemotherapy of Cancer

Pharmacogenetic testing in patients with cancer requiring cytotoxic chemotherapy offers the potential to predict, prevent, and mitigate chemotherapy-related toxicities. While multiple drug-gene pairs have been identified and studied, few drug-gene pairs are currently used routinely in the clinical status. Here we review what is known, theorized, and unknown regarding the use of pharmacogenetic testing in cancer.

Homogentisic acid, a main phenolic constituent of strawberry tree honey, protects human peripheral blood lymphocytes against irinotecan-induced cytogenetic damage in vitro

Homogentisic acid (HGA) is the most abundant phenolic compound in strawberry tree (Arbutus unedo L.) honey and an intermediate in the metabolism of phenylalanine and tyrosine. Since HGA exerts its dual nature (pro-oxidant and antioxidant), which depends on the concentration and cell type, the aim of study was to determine whether HGA possess cytoprotective effects and could counteract the cyto- and genotoxic effects of the antineoplastic drug irinotecan (IRI). Tested concentrations corresponded to HGA content in average daily dose of strawberry tree honey as well as five- and ten-fold higher concentrations. Cyto- and genoprotective effects were tested on human peripheral blood lymphocytes using chromosomal aberrations assay and cytokinesis-block micronucleus cytome assay. HGA, even at concentrations 10-fold higher than the one present in the daily amount of consumed strawberry tree honey, posed a non-significant cytotoxic threat to lymphocytes, had a negligible potential for causing cytogenetic damage in treated cells, and did not significantly impair their proliferation. Results of the chromosomal aberration assay and CBMN Cyt assay also showed that HGA efficiently counteracted the detrimental cytogenetic effects of IRI in vitro. The finding on cyto- and genoprotective effects of HGA merits further research in order to better explain the safety profile of this compound and to assess its potency for the development of novel nutraceutical products.